ribociclib and Breast-Neoplasms

The cyclin-dependent kinase 4 and 6 inhibitors (CDK4/6i) have become the standard of care for hormone receptor-positive (HR + ) and human epidermal growth factor receptor 2-negative (HER2-) metastatic breast cancer, improving survival outcomes compared to endocrine therapy alone. Abemaciclib and ribociclib, in combination with endocrine therapy, have demonstrated significant benefits in invasive disease-free survival for high-risk HR+/HER2- early breast cancer patients. Each CDK4/6i-palbociclib, ribociclib, and abemaciclib-exhibits distinct toxicity profiles. Radiation therapy (RT) can be delivered with a palliative or ablative intent, particularly using stereotactic body radiation therapy for oligometastatic or oligoprogressive disease. However, pivotal randomized trials lack information on concomitant CDK4/6i and RT, and existing preclinical and clinical data on the potential combined toxicities are limited and conflicting. As part of a broader effort to establish international consensus recommendations for integrating RT and targeted agents in breast cancer treatment, we conducted a systematic review and meta-analysis to evaluate the safety profile of combining CDK4/6i with palliative and ablative RT in both metastatic and early breast cancer settings.

Topics: Antineoplastic Combined Chemotherapy Protocols; Breast Neoplasms; Cyclin-Dependent Kinase 4; Cyclin-Dependent Kinase 6; Cyclin-Dependent Kinases; Female; Humans; Protein Kinase Inhibitors; Radiosurgery

The approval of CDK4/6 inhibitors has dramatically improved care for the treatment of HR+/HER2- advanced breast cancer, but navigating the rapidly-expanding treatment evidence base is challenging. In this narrative review, we provide best-practice recommendations for the first-line treatment of HR+/HER2- advanced breast cancer in Canada based on relevant literature, clinical guidelines, and our own clinical experience. Due to statistically significant improvements in overall survival and progression-free survival, ribociclib + aromatase inhibitor is our preferred first-line treatment for de novo advanced disease or relapse ≥12 months after completion of adjuvant endocrine therapy and ribociclib or abemaciclib + fulvestrant is our preferred first-line treatment for patients experiencing early relapse. Abemaciclib or palbociclib may be used when alternatives to ribociclib are needed, and endocrine therapy can be used alone in the case of contraindication to CDK4/6 inhibitors or limited life expectancy. Considerations for special populations-including frail and fit elderly patients, as well as those with visceral disease, brain metastases, and oligometastatic disease-are also explored. For monitoring, we recommend an approach across CDK4/6 inhibitors. For mutational testing, we recommend routinely performing ER/PR/HER2 testing to confirm the subtype of advanced disease at the time of progression and to consider

Topics: Aged; Aminopyridines; Breast Neoplasms; Female; Humans; Neoplasm Recurrence, Local

The cyclin-dependent kinase 4 and 6 (CDK4/6) inhibitors palbociclib, ribociclib, and abemaciclib are standard-of-care therapy for hormone receptor-positive advanced or metastatic breast cancer, based on randomized trials showing improved progression-free survival for all 3 drugs and overall survival for ribociclib and abemaciclib. Results in early breast cancer are discordant, with sustained improvement in invasive disease-free survival demonstrated for abemaciclib but not other CDK4/6 inhibitors to date. We review nonclinical studies exploring mechanistic differences between the drugs, the impact of continuous dosing on treatment effect, and translational research into potential resistance mechanisms and prognostic and predictive markers. We focus particularly on how emerging findings may help us understand similarities and differences between the available CDK4/6 inhibitors. Even at late-stage clinical development, there remains much to learn about how agents in this class exert their varying effects.

Topics: Aminopyridines; Breast Neoplasms; Cyclin-Dependent Kinase 4; Female; Humans

Combination therapy with cyclin-dependent kinase 4 and 6 inhibitors (CDK4/6i: palbociclib, ribociclib, abemaciclib) and endocrine therapy (ET) has been a major advance for the treatment of hormone receptor-positive (HR+), ERBB2 (formerly HER2)-negative (ERBB2-) advanced or metastatic breast cancer.. Randomized phase 3 studies demonstrated that the addition of CDK4/6i reduced the hazard risk of disease progression by approximately half compared with hormonal monotherapy (an aromatase inhibitor, tamoxifen, or fulvestrant) in the first-line (1L) and/or second-line (2L) setting. Hence, the US Food and Drug Administration and European Medicines Agency approved 3 CDK4/6i, in both 1L and 2L settings. However, differences among the CDK4/6i regarding mechanisms of action, adverse effect profiles, and overall survival (OS) are emerging. Both abemaciclib and ribociclib have demonstrated efficacy in high-risk HR+ early breast cancer. While ET with or without CDK4/6i is accepted as standard treatment for persons with advanced HR+ ERBB2- metastatic breast cancer, several key issues remain. First, why are there discordances in OS in the metastatic setting and efficacy differences in the adjuvant setting? Additionally, apart from HR status, there are few biomarkers predictive of response to CDK4/6i plus ET, and these are not used routinely. Despite the clear OS advantage noted in the 1L and 2L metastatic setting with some CDK4/6i, a subset of patients with highly endocrine-sensitive disease do well with ET alone. Therefore, an unanswered question is whether some patients can postpone CDK4/6i until the 2L setting, particularly if financial toxicity is a concern. Finally, given the lack of endocrine responsiveness following progression on some CDK4/6i, strategies to optimally sequence treatment are needed.. Future research should focus on defining the role of each CDK4/6i in HR+ breast cancer and developing a biomarker-directed integration of these agents.

Topics: Aminopyridines; Antineoplastic Combined Chemotherapy Protocols; Breast Neoplasms; Cyclin-Dependent Kinase 4; Cyclin-Dependent Kinase 6; Female; Humans; Protein Kinase Inhibitors; Receptor, ErbB-2; Triple Negative Breast Neoplasms

This network meta-analysis aimed to assess the comparative efficacy and safety of combinations involving three cyclin-dependent kinase 4/6 (CDK4/6) inhibitors and endocrine therapies (ETs) in patients with metastatic or advanced breast cancer (BC) who are hormone receptor-positive (HR+) and human epidermal growth factor receptor 2-negative (HER2-).. We initially identified relevant studies from previous meta-analyses and then conducted a comprehensive search of PubMed, Embase, and the Cochrane Central Register of Controlled Trials (CENTRAL) databases to locate additional studies published between February 2020 and September 2021. Essential data were extracted, and a network meta-analysis was performed using R 4.1.1 software with a random-effects model. Furthermore, we assigned rankings to all available treatment combinations by calculating their cumulative probability.. Data analysis included ten reports from nine studies. Pooled results demonstrated that each treatment combination significantly reduced the hazard risk of progression-free survival (PFS) compared to treatment with an aromatase inhibitor (AI) or fulvestrant alone. However, there were no differences observed in PFS or overall survival (OS) among the different treatment combinations. Additionally, patients receiving palbociclib plus AI and abemaciclib plus AI or fulvestrant experienced more severe adverse events (AEs), with hazard ratios (HRs) of 10.83 (95% confidence interval [CI] = 2.3 to 52.51) and 4.8 (95%CI = 1.41 to 16.21), respectively. The HR for ribociclib plus AI was 9.45 (95%CI = 2.02 to 43.61), and the HR for palbociclib plus fulvestrant was 6.33 (95%CI = 1.03 to 39.86). Based on the ranking probabilities, palbociclib plus fulvestrant had the highest probability of achieving superior PFS (37.65%), followed by abemaciclib plus fulvestrant (28.76%). For OS, ribociclib plus fulvestrant ranked first (34.11%), with abemaciclib plus fulvestrant in second place (25.75%). In terms of safety, palbociclib plus AI (53.98%) or fulvestrant (51.37%) had the highest probabilities of being associated with adverse events.. Abemaciclib plus fulvestrant or ribociclib plus AI appear to be effective and relatively safe for the treatment of HR+/HER2- metastatic or advanced BC patients. However, given the reliance on limited evidence, our findings require further validation through additional studies.

Topics: Aromatase Inhibitors; Breast Neoplasms; Cyclin-Dependent Kinase 4; Female; Fulvestrant; Humans; Network Meta-Analysis

Herein, we discuss more than 50 cyclin-dependent kinase (CDK) inhibitors that have been approved or have undergone clinical trials and their therapeutic application in multiple cancers. This review discusses the design strategies, structure-activity relationships, and efficacy performances of these selective or nonselective CDK inhibitors. The theoretical basis of early broad-spectrum CDK inhibitors is similar to the scope of chemotherapy, but because their toxicity is greater than the benefit, there is no clinical therapeutic window. The notion that selective CDK inhibitors have a safer therapeutic potential than pan-CDK inhibitors has been widely recognized during the research process. Four CDK4/6 inhibitors have been approved for the treatment of breast cancer or for prophylactic administration during chemotherapy to protect bone marrow and immune system function. Furthermore, the emerging strategies in the field of CDK inhibitors are summarized briefly, and CDKs continue to be widely pursued as emerging anticancer drug targets for drug discovery.

Topics: Antineoplastic Agents; Breast Neoplasms; Cell Cycle; Cyclin-Dependent Kinase 4; Cyclin-Dependent Kinase 6; Cyclin-Dependent Kinases; Female; Humans; Pharmaceutical Preparations; Protein Kinase Inhibitors

Cyclin-dependent kinase 4 and 6 (CDK4/6) inhibitors have revolutionized the treatment of hormone-positive metastatic breast cancers (mBCs). They are currently established as standard therapies in combination with endocrine therapy as first- and second-line systemic treatment options for both endocrine-sensitive and endocrine-resistant mBC populations. In the first-line metastatic setting, the median progression-free survival for the three currently approved CDK4/6 inhibitors, palbociclib, ribociclib, and abemaciclib, with aromatase inhibitors is greater than 2 years (palbociclib 27.6 months; ribociclib 25.3 months; and abemaciclib 28.18 months). Although CDK4/6 inhibitors have significant clinical benefits and enable physicians to delay starting chemotherapy, they are expensive and can be associated with drug toxicities. Here, we have performed a systemic review of the reported molecular markers predictive of drug response including intrinsic and acquired resistance for CDK4/6 inhibition in mBC. The rapidly emerging molecular landscape is captured through next-generation sequencing of breast cancers (DNA with or without RNA), liquid biopsies (circulating tumor DNA), and protein analyses. Individual molecular candidates with robust and reliable evidence are discussed in more depth.

Topics: Aminopyridines; Antineoplastic Agents; Benzimidazoles; Biomarkers, Tumor; Breast Neoplasms; Cyclin-Dependent Kinase 4; Cyclin-Dependent Kinase 6; Drug Resistance, Neoplasm; Female; Humans; Piperazines; Prognosis; Purines; Pyridines

Cyclin-dependent kinase 4/6 (CDK4/6) inhibitors abemaciclib, palbociclib, and ribociclib radically modified the treatment of hormone receptor-positive/human epidermal growth factor 2-negative advanced breast cancer. Ribociclib efficacy was proved in the phase III MONALEESA-2, -3, and -7 trials. In the first-line setting, ribociclib plus endocrine therapy determined statistically significant improvements in progression-free (PFS) and overall survival (OS) in pre-menopausal (MONALEESA-7) and post-menopausal (MONALEESA-2) women. Likewise, ribociclib and fulvestrant induced a significant PFS and OS benefit in post-menopausal women previously treated with endocrine therapy (MONALEESA-3). Additionally, ribociclib did not affect patients health-related quality of life in all the MONALEESA trials.. We reviewed the results of the available randomized phase III trials testing ribociclib and endocrine therapy in advanced breast cancer, focusing on different patient subgroups and then on health-related quality of life.. The benefit of ribociclib is consistent across patient subgroups and is maintained in populations with unfavorable features, such as those with endocrine resistance or visceral metastases. Furthermore, the addition of ribociclib to endocrine therapy delays quality of life deterioration and improves pain scores. These results represent a pivotal improvement for the treatment of advanced breast cancer patients receiving CDK4/6 inhibitors.

Topics: Aminopyridines; Antineoplastic Combined Chemotherapy Protocols; Breast Neoplasms; Clinical Trials, Phase III as Topic; Cyclin-Dependent Kinase 4; Female; Humans; Patient Reported Outcome Measures; Purines; Quality of Life; Randomized Controlled Trials as Topic; Receptor, ErbB-2

Evaluation of health-related quality of life (HR-QoL) among cancer patients has gained an increasing importance and is now a key determinant of anticancer treatments' value. HR-QoL has been assessed in trials testing cyclin-dependent kinase 4/6 inhibitors (CDK4/6i) in breast cancer (BC), using various questionnaires at different timepoints. HR-QoL reports from BC patients treated with CDK4/6i in the real-world setting are also available.. We systematically reviewed the literature, searching for full-length articles, and selected conference abstracts reporting data on HR-QoL in BC patients at any stage and of any molecular subtype treated with abemaciclib, palbociclib or ribociclib.. A total of 533 full-length articles and 143 abstracts were retrieved. After screening for eligibility, 38 records were included (31 clinical trials; 7 real-world reports). Assessment methods were heterogeneous across studies in terms of questionnaires, evaluation timepoints and endpoints. Overall, adding CDK4/6i to endocrine therapy did not worsen patients' HR-QoL, with a positive trend towards pain improvement. Gastrointestinal scores (diarrhea, nausea and appetite loss) statistically favored the control arm among metastatic BC patients receiving abemaciclib, whereas they were superimposable in the early setting. The combination of palbociclib and endocrine therapy showed similar HR-QoL outcomes compared with endocrine therapy alone, but determined better scores compared with chemotherapy. HR-QoL was specifically assessed in premenopausal patients treated with ribociclib, showing similar scores compared with postmenopausal patients.. Despite methodological heterogeneity does not allow a proper comparison, HR-QoL was generally maintained with CDK4/6i. However, differences between abemaciclib, palbociclib and ribociclib exist and mainly rely on the distinct safety profiles of the compounds. These differences should be acknowledged and taken into account in the clinical practice.

Topics: Aminopyridines; Breast Neoplasms; Cyclin-Dependent Kinase 4; Cyclin-Dependent Kinase 6; Female; Humans; Protein Kinase Inhibitors; Quality of Life

Topics: Aminopyridines; Breast Neoplasms; Cardiac Conduction System Disease; Clinical Trials, Phase III as Topic; Female; Humans; Neoplasm Metastasis; Purines; Randomized Controlled Trials as Topic; Risk Factors

Endocrine therapy (ET) is a standard first-line treatment for hormone receptor-positive, human epidermal growth factor receptor 2-negative (HR+/HER2-) advanced breast cancer (ABC) Cyclin-dependent kinase 4/6 inhibitors (CDK4/6i) have demonstrated significantly improved progression-free survival (PFS) with ET in patients with ABC. Recent reports indicate that the addition of the CDK4/6i ribociclib to ET, including fulvestrant, significantly improves PFS and overall survival (OS).. This review summarizes the efficacy and safety of ribociclib plus fulvestrant in HR+/HER2- ABC and its role in clinical practice. Various post-progression strategies are discussed.. In MONALEESA-3, ribociclib +fulvestrant significantly improved PFS and OS in postmenopausal patients who received no prior chemotherapy and ≤1 prior line of ET for ABC and benefited many patient subgroups, including those with visceral metastases and ET resistance. The safety of this combination is manageable and consistent with the known safety profile of ribociclib, with myelosuppression being a common and expected toxicity; other relevant toxicities requiring monitoring that occur at a low rate include hepatobiliary toxicity, pneumonitis, and QTc prolongation. There is an important role for CDK4/6i + ET, including ribociclib + fulvestrant, in clinical practice. The optimal position of CDK4/6i in first or subsequent lines of treatment and the optimal post-CDK4/6i progression strategies are not yet elucidated.

Topics: Aminopyridines; Antineoplastic Combined Chemotherapy Protocols; Breast Neoplasms; Disease Progression; Female; Fulvestrant; Humans; Progression-Free Survival; Purines; Randomized Controlled Trials as Topic; Survival Rate

HER2-positive (HER2+) breast cancer represents a heterogeneous breast cancer subtype, including both oestrogen receptor (ER) positive and negative tumours. A deeper understanding of the crosstalk between ER and HER2 receptor pathways has led to the development of treatment strategies consisting of a simultaneous blockade of both signalling pathways, as a reasonable approach to prevent the onset of mechanisms of resistance.. This review was based on the material searched on PubMed, MEDLINE and Embase databases and on conference proceedings from major oncology conferences up to 15 December 2020. The search strategy included the following keywords: 'HER2-positive breast cancer', 'CDK4-6 inhibitors' and 'PI3K inhibitors', and was adapted for use with different bibliographic databases.. CDK4/6 and PI3K inhibitors are two classes of agents already approved in patients with hormone receptor positive, HER2-negative breast cancer. Recently, promising data with their use have been also shown in HER2+ disease. Results from preclinical and clinical studies are shedding light on the role of these classes of agents in HER2+ breast cancer, and are paving the road for a forthcoming change in clinical practice.. Treatment landscape for HER2+ breast cancer is rapidly changing, and CDK4/6 and PI3K inhibitors represent a new promising strategy to improve patients' outcomes.

Topics: Aminopyridines; Anastrozole; Antibodies, Monoclonal, Humanized; Antineoplastic Agents, Hormonal; Antineoplastic Agents, Immunological; Benzimidazoles; Breast Neoplasms; Cyclin-Dependent Kinase 4; Cyclin-Dependent Kinase 6; Female; Fulvestrant; Humans; Letrozole; Phosphoinositide-3 Kinase Inhibitors; Piperazines; Protein Kinase Inhibitors; Purines; Pyridines; Receptor, ErbB-2; Receptors, Estrogen; Receptors, Progesterone; Tamoxifen; Trastuzumab

The historical median survival of advanced luminal breast cancer does not exceed four years. The deciphering of the mechanisms of resistance to hormone therapy has led to the development of inhibitors of cyclin D dependent kinases (CDK4 and 6). Three drugs, palbociclib, ribociclib and abemaciclib, very similar pharmacologically, have been evaluated in the context of pivotal, randomized phase III trials. Strikingly and regardless of the endocrine therapy backbone, and in both hormone-sensitive and hormone-resistant patients, the addition of a CDK4 / 6 inhibitor doubles progression-free survival with a hazard ratio always around 0.55. The benefit in overall survival begins to be demonstrated. This review presents all published results, as well as the main safety data.

Topics: Aminopyridines; Benzimidazoles; Breast Neoplasms; Cell Cycle; Clinical Trials, Phase III as Topic; Cyclin-Dependent Kinase 4; Cyclin-Dependent Kinase 6; Female; Humans; Piperazines; Progression-Free Survival; Proportional Hazards Models; Protein Kinase Inhibitors; Purines; Pyridines; Randomized Controlled Trials as Topic; Retinoblastoma Binding Proteins; Ubiquitin-Protein Ligases

A 72-year-old woman with metastatic ER/PR-positive breast cancer who had been on ribociclib and letrozole for 1 year developed severe life-threatening colitis. She presented to emergency department with features of acute abdomen and diarrhoea. The diagnosis of colitis was confirmed radiologically as well as by histopathological examination of the biopsy specimen and the patient clinically improved after withholding ribociclib and receiving corticosteroids compatible with ribociclib-induced colitis. The mechanism of injury in CDK 4/6 inhibitor-induced colitis is unknown but may be related to recruitment of inflammatory cells. Whether the development of colitis is associated with tumour response is an interesting and unanswered question.

Topics: Aged; Aminopyridines; Antineoplastic Combined Chemotherapy Protocols; Breast Neoplasms; Colitis; Cyclin-Dependent Kinase 4; Cyclin-Dependent Kinase 6; Female; Humans; Letrozole; Purines; Receptor, ErbB-2; Receptors, Estrogen

Over the past years, planet oncology has kept changing and moving forward. Recent results of important clinical trials are challenging our daily practices. With modesty, the Editorial Board of BulletinduCancer has selected some clinical trials they consider as "must-know about" even if they go beyond our medical fields.

Topics: Aminopyridines; Breast Neoplasms; Clinical Trials as Topic; Digestive System Neoplasms; Female; Genital Neoplasms, Female; Humans; Lung Neoplasms; Male; Molecular Targeted Therapy; Neoplasms; Neoplasms, Unknown Primary; Prostatic Neoplasms; Purines

Topics: Alopecia; Aminopyridines; Antineoplastic Combined Chemotherapy Protocols; Benzimidazoles; Breast Neoplasms; Clinical Trials, Phase II as Topic; Clinical Trials, Phase III as Topic; Cyclin-Dependent Kinase 4; Cyclin-Dependent Kinase 6; Estrogen Receptor alpha; Female; Fulvestrant; Germany; Humans; Incidence; Neoplasm Metastasis; Piperazines; Protein Kinase Inhibitors; Purines; Pyridines; Quality of Life; Randomized Controlled Trials as Topic; Receptors, Progesterone; Survival Rate; Tamoxifen

Palbociclib, ribociclib and abemaciclib have all been approved in combination with endocrine therapy in hormone-receptor positive, HER2 negative metastatic breast cancer. While the efficacy of these drugs appears similar, differences in safety and tolerability are apparent.. We searched PubMed and ASCO, ESMO and SABCS proceedings to identify randomized trials of palbociclib, ribociclib and abemaciclib. Data on common and serious adverse events (AE) were extracted for each approved drug. The odds ratio for each AE and the hazard ratio for progression-free survival were calculated relative to endocrine therapy alone. A network meta-analysis was then performed for each endocrine therapy backbone (aromatase inhibitor (AI) or fulvestrant) to compare ribociclib and abemaciclib to palbociclib.. 8 trials were included in the analysis and comprised 2799 patients receiving cyclin-dependent kinase 4/6 inhibitors palbociclib: 873 patients; ribociclib: 1153 patients; abemaciclib: 773 patients. In 5 trials (1524 patients), the endocrine therapy backbone was an AI and in 3 trials (1275 patients) it was fulvestrant. Compared to palbociclib, ribociclib and abemaciclib showed significantly lower grade 3-4 neutropenia, but significantly higher GI toxicity. Treatment discontinuation was higher with abemaciclib than other drugs. Efficacy of the 3 drugs was similar. Compared to palbociclib, for AI backbone, the HR for PFS for ribociclib was 0.98 and for abemaciclib 1.02. For fulvestrant backbone, the HR were 0.88 and 0.93 respectively.. Palbociclib, ribociclib and abemaciclib have comparable efficacy, but differences in safety and tolerability. Abemaciclib has worse tolerability with significantly higher treatment discontinuation likely due to GI toxicity.

Topics: Aminopyridines; Antineoplastic Agents; Benzimidazoles; Breast Neoplasms; Cyclin-Dependent Kinase 4; Cyclin-Dependent Kinase 6; Female; Humans; Neoplasm Metastasis; Network Meta-Analysis; Piperazines; Protein Kinase Inhibitors; Purines; Pyridines; Randomized Controlled Trials as Topic

Palbociclib, ribociclib, and abemaciclib are inhibitors of the cyclin-dependent kinases 4 and 6 approved for the treatment of locally advanced or metastatic breast cancer. In this review, we provide an overview of the available clinical pharmacokinetic and pharmacodynamic characteristics of these novel drugs, summarize the results of food-effect and drug-drug interaction studies, and highlight exposure-response and exposure-toxicity relationships. All three drugs exhibit a large inter-individual variability in exposure (coefficient of variation range 40-95% for minimum plasma concentration), are extensively metabolized by cytochrome P450 3A4, and have their brain penetration limited by efflux transporters. Abemaciclib has three active metabolites with similar potency that are clinically relevant (i.e., M2, M20, M18), whereas the metabolites of palbociclib and ribociclib are not of clinical significance. Pharmacokinetic exposure increases in a dose-proportional manner for palbociclib, whereas exposure increases under- and over-proportionally with an increasing dose for abemaciclib and ribociclib, respectively. High exposure is associated with an increased risk of neutropenia, and for ribociclib also to corrected QT prolongation. For abemaciclib, a clear exposure-efficacy relationship has been described, while for palbociclib and ribociclib exposure-response analyses remain inconclusive. Future studies are needed to address exposure-efficacy relationships to further improve dosing.

Topics: Aminopyridines; Antineoplastic Agents; Benzimidazoles; Breast Neoplasms; Cyclin-Dependent Kinase 4; Cyclin-Dependent Kinase 6; Female; Humans; Piperazines; Protein Kinase Inhibitors; Purines; Pyridines

Sustained proliferative capacity and gene dysregulation are hallmarks of cancer. In mammalian cells, cyclin-dependent kinases (CDKs) control critical cell cycle checkpoints and key transcriptional events in response to extracellular and intracellular signals leading to proliferation. Significant clinical activity for the treatment of hormone receptor positive metastatic breast cancer has been demonstrated by palbociclib, ribociclib and abemaciclib, dual CDK4/6 inhibitors recently FDA-approved. SY-1365, a CDK7 inhibitor has shown initial encouraging data in phase I for solid tumors treatment. These results have rejuvenated the CDKs research field. This review provides an overview of relevant advances on CDK inhibitor research since 2015 to 2019, with special emphasis on transcriptional CDK inhibitors, new emerging strategies such as target protein degradation and compounds under clinical evaluation.

Topics: Aminopyridines; Animals; Antineoplastic Agents; Benzimidazoles; Breast Neoplasms; Cell Cycle Checkpoints; Cyclin-Dependent Kinases; Drug Discovery; Humans; Indoles; Piperazines; Protein Kinase Inhibitors; Purines; Pyridines; Pyrimidines; Transcription Factors

Although international guidelines support the administration of hormone therapies with or without targeted therapies in postmenopausal women with hormone-receptor-positive, HER2-negative metastatic breast cancer, upfront use of chemotherapy remains common even in the absence of visceral crisis. Because first-line or second-line treatments, or both, based on chemotherapy and on hormone therapy have been scarcely investigated in head-to-head randomised controlled trials, we aimed to compare these two different approaches.. We did a systematic review and network meta-analysis with a systematic literature search on PubMed, Embase, Cochrane Central Register of Clinical Trials, Web of Science, and online archives of the most relevant international oncology conferences. We included all phase 2 and 3 randomised controlled trials investigating chemotherapy with or without targeted therapies and hormone therapies with or without targeted therapies as first-line or second-line treatments, or both, in postmenopausal women with hormone-receptor-positive, HER2-negative metastatic breast cancer, published between Jan 1, 2000, and Dec 31, 2017. Additional recently published randomised controlled trials relevant to the topic were also subsequently added. No language restrictions were adopted for our search. A Bayesian network meta-analysis was done to compare hazard ratios (HRs) for progression-free survival (the primary outcome), and to compare odds ratios (ORs) for the proportion of patients achieving an overall response (the secondary outcome). All treatments were compared to anastrozole and to palbociclib plus letrozole. This study is registered in the Open Science Framework online public database, registration DOI 10.17605/OSF.IO/496VR.. We identified 2689 published results and 140 studies (comprising 50 029 patients) were included in the analysis. Palbociclib plus letrozole (HR 0·42; 95% credible interval [CrI] 0·25-0·70), ribociclib plus letrozole (0·43; 0·24-0·77), abemaciclib plus anastrozole or letrozole (0·42; 0·23-0·76), palbociclib plus fulvestrant (0·37; 0·23-0·59), ribociclib plus fulvestrant (0·48; 0·31-0·74), abemaciclib plus fulvestrant (0·44; 0·28-0·70), everolimus plus exemestane (0·42; 0·28-0·67), and, in patients with a PIK3CA mutation, alpelisib plus fulvestrant (0·39; 0·22-0·66), and several chemotherapy-based regimens, including anthracycline and taxane-containing regimens, were associated with better progression-free survival than was anastrozole alone. No chemotherapy or hormone therapy regimen was significantly better than palbociclib plus letrozole for progression-free survival. Paclitaxel plus bevacizumab was the only clinically relevant regimen that was significantly better than palbociclib plus letrozole in terms of the proportion of patients achieving an overall response (OR 8·95; 95% CrI 1·03-76·92).. In the first-line or second-line setting, CDK4/6 inhibitors plus hormone therapies are better than standard hormone therapies in terms of progression-free survival. Moreover, no chemotherapy regimen with or without targeted therapy is significantly better than CDK4/6 inhibitors plus hormone therapies in terms of progression-free survival. Our data support treatment guideline recommendations involving the new combinations of hormone therapies plus targeted therapies as first-line or second-line treatments, or in both settings, in women with hormone-receptor-positive, HER2-negative metastatic breast cancer.. None.

Topics: Aminopyridines; Anastrozole; Androstadienes; Antineoplastic Agents, Hormonal; Antineoplastic Combined Chemotherapy Protocols; Benzimidazoles; Bevacizumab; Breast Neoplasms; Clinical Trials, Phase II as Topic; Clinical Trials, Phase III as Topic; Everolimus; Female; Fulvestrant; Humans; Letrozole; Network Meta-Analysis; Paclitaxel; Piperazines; Postmenopause; Progression-Free Survival; Purines; Pyridines; Randomized Controlled Trials as Topic; Receptor, ErbB-2; Receptors, Estrogen; Receptors, Progesterone

Both palbociclib and abemaciclib are, oral, highly selective inhibitors of cyclin-dependent kinase 4 and 6, which are proteins involved in cell differentiation and growth. In pivotal phase III trials (PALOMA and MONARCH), they demonstrated a significant improvement in median progression-free survival in combination with a nonsteroidal aromatase inhibitor in the first-line, and with a fulvestrant in the second-line in hormone receptor-positive and HER2-negative metastatic breast cancer, respectively. Both palbociclib and abemaciclib were approved, however, ribociclib, the third cyclin-dependent kinase 4/6 inhibitor, has not been approved in Japan. The overall benefits from palbociclib and abemaciclib seem to be equivalent. Subsets analyses suggest that clinical benefits of palbociclib are associated with bone-only disease at baseline, no measurable disease, sensitive to previous endocrine therapy and longer disease-free interval. In contrast, additional benefits from abemaciclib in combination with nonsteroidal aromatase inhibitor or fulvestrant seem to have a relationship with visceral disease, liver metastasis, primary resistant to endocrine therapy, and short treatment-free interval. Abemaciclib induces senescence and apoptosis more than palbociclib does in a time-dependent manner and has potential to produce tumor shrinkage by single use. Neutropenia is more frequent in palbociclib, in contrast, diarrhea, nausea, and liver dysfunction are frequent in abemaciclib. In this review, we provide an overview of the two kinds of cyclin-dependent kinase 4/6 inhibitor, which were already approved in Japan. These differences might be useful information for the proper use in daily practice.

Topics: Aminopyridines; Antineoplastic Agents; Apoptosis; Aromatase Inhibitors; Benzimidazoles; Breast Neoplasms; Cyclin-Dependent Kinase 4; Cyclin-Dependent Kinase 6; Female; Fulvestrant; Humans; Japan; Piperazines; Protein Kinase Inhibitors; Purines; Pyridines

Cyclin-dependent kinase 4/6 inhibitors, which act by inhibiting progression from the G1 to S phases of the cell cycle, include palbociclib, ribociclib, abemaciclib, and trilaciclib. Palbociclib and ribociclib are currently food and drug administration-approved for use in combination with aromatase inhibitors in postmenopausal women with metastatic hormone receptor-positive, human epidermal growth factor receptor 2-negative breast cancer. Palbociclib is also food and drug administration-approved for use in combination with fulvestrant in hormone receptor-positive, human epidermal growth factor receptor 2-negative breast cancer progressing after endocrine therapy. Abemaciclib is the newest cyclin-dependent kinase 4/6 inhibitor to gain Food and Drug Administration (FDA) approval, specifically as monotherapy for hormone receptor-positive, human epidermal growth factor receptor 2-negative metastatic breast cancer previously treated with chemotherapy and endocrine therapy. Abemaciclib also shares a similar indication with palbociclib for use in combination with fulvestrant in hormone receptor-positive, human epidermal growth factor receptor 2-negative breast cancer progressing after endocrine therapy. Trilaciclib use remains largely investigational at this time. However, despite FDA-approval for only metastatic hormone receptor-positive, human epidermal growth factor receptor 2-negative breast cancer, all four cyclin-dependent kinase 4/6 inhibitors have shown promise in hematologic malignancies and non-breast solid tumors. Although further research is needed, cyclin-dependent kinase 4/6 inhibitors represent intriguing developments in the treatment of various malignancies, including those with such poor prognoses as glioblastoma multiforme, mantle cell lymphoma, and metastatic melanoma. We discuss the approved indications, current research, and areas of future exploration for palbociclib, ribociclib, abemaciclib, and trilaciclib.

Topics: Aminopyridines; Benzimidazoles; Breast Neoplasms; Clinical Trials as Topic; Cyclin-Dependent Kinase 4; Cyclin-Dependent Kinase 6; Female; Forecasting; Humans; Piperazines; Protein Kinase Inhibitors; Purines; Pyridines; Receptor, ErbB-2; Treatment Outcome

Despite the recent advances in breast cancer early detection and awareness, a significant portion of patients present with an advanced-stage disease and more patients will progress to stage IV despite adequate treatment of their initial early-stage disease. Hormone receptor (HR)-positive, Human Epidermal Growth Factor Receptor-2 (HER2)-negative subtype is the commonest among all breast cancer subtypes. The management of the advanced-stage disease of this subtype has evolved significantly over the past few years. The emergence of estrogen receptor down regulators (fulvestrant), mTOR-inhibitors and the recent introduction of CDK4/6 inhibitors, like palbociclib, abemaciclib and ribociclib, has resulted in a significant and a historical improvement in treatment outcomes. In this paper, we review many of the recently reported clinical trials that led to the approval of these new drugs in the first-line settings, along with the current international guidelines.

Topics: Aminopyridines; Benzimidazoles; Breast Neoplasms; Female; Fulvestrant; Humans; Neoplasm Staging; Piperazines; Purines; Pyridines; Receptor, ErbB-2

To evaluate the existing literature regarding the use of cyclin-dependent kinase (CDK) 4/6 inhibitors in the treatment of hormone receptor-positive advanced breast cancer (ABC).. A search of the medical literature was performed using PubMed (2014 to June 2018). Search terms included cyclin-dependent kinase, CDK, breast cancer, palbociclib, ribociclib, abemaciclib, PD0332991, LEE011, and LY2835219. Clinicaltrials.gov was also searched.. Trials with clinical efficacy outcomes evaluating CDK 4/6 inhibitors in the treatment of advanced hormone-positive breast cancer were considered.. Palbociclib, abemaciclib, and ribociclib each demonstrated significant benefit when combined with an aromatase inhibitor, the benefit to patients was similar for each, with an improvement of 42% to 51% in median progression-free survival (PFS). In combination with fulvestrant, CDK 4/6 inhibitors used for the treatment of hormone receptor-positive ABC resulted in a 43% to 58% improvement in median PFS versus fulvestrant alone. CDK inhibitors are relatively well tolerated; however, discontinuation as a result of adverse effects was highest with abemaciclib. Relevance to Patient Care and Clinical Practice: This review considers the use of the 3 commercially available CDK 4/6 inhibitors for treatment of hormone receptor-positive breast cancer, including data on each of the 3 agents in newly advanced and treatment refractory disease.. The CDK inhibitors should be used in combination with endocrine therapies for the treatment of ABC. Efficacy of the 3 agents is similar. Selection within the class should include consideration of adverse effects and drug interactions.

Topics: Aminopyridines; Aromatase Inhibitors; Benzimidazoles; Breast Neoplasms; Cyclin-Dependent Kinase 4; Cyclin-Dependent Kinase 6; Disease Progression; Female; Humans; Piperazines; Protein Kinase Inhibitors; Purines; Pyridines; Receptor, ErbB-2

Topics: Aminopyridines; Antineoplastic Combined Chemotherapy Protocols; Aromatase Inhibitors; Breast Neoplasms; Cost-Benefit Analysis; Female; Humans; Models, Economic; Purines; Randomized Controlled Trials as Topic; Receptors, Estrogen; Technology Assessment, Biomedical

Topics: Aminopyridines; Breast Neoplasms; Cyclin-Dependent Kinase 4; Cyclin-Dependent Kinase 6; Drug Resistance, Neoplasm; Lymphocytes, Tumor-Infiltrating; Piperazines; Protein Kinase Inhibitors; Purines; Pyridines; Receptors, Estrogen; Tumor Microenvironment

Metastatic or advanced breast cancer (mBC/ABC) remains incurable despite many different systemic treatment options. Hormone receptor positive (HR+) disease represents the most common subtype in both early and advanced disease. A better understanding of the biology of this BC subtype, in particular regarding potential mechanisms of endocrine resistance, has led to the development of CDK4/6 inhibitors. All three selective CDK4/6 inhibitors, palbociclib, ribociclib and abemaciclib have shown to significantly improve progression-free survival (PFS) when combined to endocrine therapy as first-line treatment for patients with HR+/HER-2 negative ABC, who have progressed on or after adjuvant endocrine therapy. All three of them have also shown an improved PFS as 2nd line therapy for HR+/Her2 negative ABC. Their toxicity profile is favorable, with hematological toxicity (mainly neutropenia) being predominant, followed by diarrhea and fatigue. Quality of life has been maintained in the 1st line setting or improved in the 2nd line setting. Overall survival (OS) has been reported so far only in 2 out of 7 trials as first line therapy and the difference did not reach statistical significance. In this article we review the biology of CDK signaling pathway and its inhibitors, preclinical and clinical data of all three investigated selective CDK4/6 inhibitors and their toxicity. We also discuss how these agents are being included in current international guidelines and future directions for these agents in other subtypes of breast cancer, in both advanced disease and early-stage disease.

Topics: Aminopyridines; Benzimidazoles; Breast Neoplasms; Cyclin-Dependent Kinase 4; Cyclin-Dependent Kinase 6; Humans; Molecular Targeted Therapy; Piperazines; Progression-Free Survival; Protein Kinase Inhibitors; Purines; Pyridines; Receptors, Estrogen; Receptors, Progesterone; Signal Transduction

Recently, new targeted agents have been developed, which can prolong the effect of endocrine treatment (ET) by targeting resistance pathways in HR+/HER2- advanced breast cancer. This review examines available studies of everolimus, an mTOR inhibitor, and the CDK 4/6 inhibitors ribociclib, palbociclib and abemaciclib in terms of efficacy, tolerability and safety.. A systematic literature search was performed in Pubmed. Evaluation of the quality of the identified studies was based on selected elements from the GRADE guidelines.. The literature search yielded eight randomized trials that all presented a significant increase in the progression free survival (PFS)/time to progression (TTP) for the targeted agents plus ET vs ET only. The improvement was evident as first-line therapy with an increase in PFS of 10-11 months when adding a CDK4/6 inhibitor to ET, as well as in patients previously treated for metastatic disease, with an increase of 5-6 months. The common adverse events (AEs) of the CDK 4/6 inhibitors were due to myelosuppression. In addition, abemaciclib was associated with liver toxicity and diarrhea, and ribociclib with liver toxicity and QTcF prolongation. The most common grade 3/4 AE of everolimus was stomatitis. The majority (five) of the trials had no serious limitations, and thus the quality of evidence was high.. The new targeted agents are all associated with an improvement of the PFS with an acceptable tolerability, and they should be offered to women with advanced HR+/HER2- breast cancer both as first-line therapy as well as among patients previously treated in metastatic regimens. However, further data regarding the impact on overall survival are required to evaluate the full benefit for patients. Price and differences in AEs could become substantial arguments for the choice of therapy for the individual patient.

Topics: Aminopyridines; Antineoplastic Agents, Hormonal; Antineoplastic Combined Chemotherapy Protocols; Benzimidazoles; Breast Neoplasms; Disease Progression; Drugs, Investigational; Everolimus; Female; Humans; Molecular Targeted Therapy; Piperazines; Purines; Pyridines; Randomized Controlled Trials as Topic; Receptor, ErbB-2; Receptors, Cytoplasmic and Nuclear; Treatment Outcome

Adding cyclin-dependent kinase (CDK) 4/6 inhibitor to endocrine therapy improves progression-free survival (PFS) in advanced breast cancer but the impact of ethnicity on efficacy and toxicity is unclear. We aimed to estimate the relative treatment efficacy and toxicity of endocrine therapy with and without CDK4/6 inhibitors, and compare between Asian/non-Asian subgroups.. This meta-analysis included published first-line randomized trials comparing CDK4/6 inhibitor-endocrine therapy versus endocrine monotherapy. Hazard ratios (HR) and 95% confidence intervals (CI) for the overall population and Asian/non-Asian subgroups were extracted. The inverse-variance-weighted method was used to pool treatment estimates of PFS.. Four trials (N = 2499) were included. Patients received combination CDK4/6 inhibitor-endocrine therapy (N = 1441; ribociclib, [46.4%]; palbociclib, [30.8%]; or abemaciclib, [22.8%]) versus endocrine monotherapy (N = 1058). CDK4/6 inhibitor-endocrine therapy was associated with prolonged PFS compared with endocrine monotherapy (HR 0.56; 95% CI 0.50-0.62). In Asians (N = 492), PFS HR was 0.39 (95% CI 0.29-0.51, P < 0.0001). In non-Asians (N = 2007), PFS HR was 0.62 (95% CI 0.54-0.71, P < 0.0001). There was a significant treatment-by-ethnicity interaction (P = 0.002). Toxicity data by ethnic subgroup were only available from two trials (n = 1334) with no convincing evidence that the risk of toxicity between CDK4/6 inhibitor-endocrine therapy and endocrine monotherapy varied by ethnicity.. Adding CDK4/6 inhibitor to endocrine therapy prolongs PFS compared to endocrine therapy alone as first-line treatment in advanced breast cancer. The magnitude of PFS benefit is ethnicity-dependent but there is no interethnic differences in relative treatment-related toxicities. These findings may assist in the design and interpretation of trials, inform economic analyses, and stimulate pharmacogenomic research.

Topics: Aminopyridines; Antineoplastic Agents, Hormonal; Antineoplastic Combined Chemotherapy Protocols; Asian People; Benzimidazoles; Breast Neoplasms; Cyclin-Dependent Kinase 4; Cyclin-Dependent Kinase 6; Female; Humans; Piperazines; Progression-Free Survival; Protein Kinase Inhibitors; Purines; Pyridines

To review the chemistry, pharmacology, pharmacokinetics, safety, and efficacy of ribociclib (LEE011, Kisqali) in hormone receptor-positive/human epidermal growth factor receptor-2-negative (HR+/HER2-) metastatic breast cancer.. A PubMed search was performed using the terms 'Ribociclib', 'Kisqali', and 'LEE011' between May 2018 and November 2018. References of published articles and reviews were also assessed for additional information.. English-language preclinical and clinical studies on the chemistry, pharmacology, pharmacokinetics, safety, and efficacy of ribociclib were evaluated.. Ribociclib, a cyclin-dependent kinase (CDK) 4/6 inhibitor, is Food and Drug Administration (FDA) approved in combination with endocrine therapy for treatment of HR+/HER2- advanced or metastatic breast cancer in premenopausal/perimenopausal and postmenopausal women. Three phase III trials have evaluated ribociclib in combination with endocrine therapy, including letrozole, anastrozole, tamoxifen, and fulvestrant. These studies found that ribociclib 600 mg/d, 21 days on, 7 days off, leads to a significantly greater median progression-free survival (PFS), ranging from 8 to 13 months. Ribociclib is well tolerated in elderly patients, maintains health-related quality of life, and significantly reduces pain scores. The dose-limiting toxicities found in phase I studies were neutropenia, thrombocytopenia, and QTc prolongation. Common adverse effects seen in phase III trials include neutropenia, leukopenia, nausea, diarrhea, vomiting, and fatigue. Relevance to Patient Care and Clinical Practice: Literature on the safety and efficacy of ribociclib as well as its place in therapy in comparison to other FDA-approved CDK4/6 inhibitors for breast cancer is discussed.. Ribociclib, when added to endocrine therapy, significantly improves PFS and has manageable toxicity in premenopausal/perimenopausal and postmenopausal women with HR+/HER2- advanced breast cancer.

Topics: Adult; Aged; Aminopyridines; Antineoplastic Combined Chemotherapy Protocols; Breast Neoplasms; Disease Progression; Female; Humans; Neoplasm Metastasis; Premenopause; Purines; Quality of Life; Receptor, ErbB-2; Receptors, Estrogen

Several trials have demonstrated the benefit of anti-CDK4/6 inhibitors plus endocrine therapy in estrogen receptor-positive (ER+) advanced breast cancer (BC), in first or subsequent lines of therapy. However, due to the lack of direct/indirect comparisons, there are no data demonstrating the superiority of one drug over the other. We compared the effectiveness of palbociclib, ribociclib, and abemaciclib in advanced ER + BC via an indirect adjusted analysis.. We performed electronic searches in the PubMed, EMBASE, and Cochrane databases for prospective phase 3 randomized trials evaluating anti-CDK4/6 inhibitors plus endocrine agents. We compared the results with an adjusted indirect analysis of randomized-controlled trials. Outcomes of interest were progression-free survival (PFS), overall response rate (ORR) and G3-4 toxicities occurring in ≥ 5% of patients.. Six trials and six treatment arms including a total of 3743 participants, were included. For PFS and ORR analysis, the three agents were similar in both first- and second-line studies. All G3-4 toxicities were similar, with reduced risk of diarrhea for palbociclib versus abemaciclib (relative risk [RR] 0.13, 95% CI 0.02-0.92; P = 0.04) and of QTc prolongation for palbociclib versus ribociclib (RR 0.02, 95% CI 0-0.83; P = 0.03). Despite different inclusion criteria and length of follow-up, similar features were noticed among second-line studies with the exception of increased risk of anemia G3-4 and diarrhea G3-4 for abemaciclib.. Based on PFS and ORR results of this indirect meta-analysis, palbociclib, ribociclib, and abemaciclib are equally effective in either first- or second-line therapy for advanced ER + BC. They, however, ported different toxicity profiles.

Topics: Aminopyridines; Benzimidazoles; Breast Neoplasms; Clinical Trials, Phase III as Topic; Female; Humans; Piperazines; Prospective Studies; Purines; Pyridines; Randomized Controlled Trials as Topic; Receptors, Estrogen; Survival Analysis; Treatment Outcome

The majority of patients with metastatic breast cancer (MBC) have hormone receptor-positive HER2-negative disease. For this subgroup, endocrine therapy is the key therapeutic option. Recently, therapeutic options have been expanded by introduction of the inhibitors of cyclin-dependent kinases 4/6 (CDK4/6i). Three compounds, palbociclib, ribociclib, and abemaciclib, have already been approved by the FDA for use together with endocrine therapy such as aromatase inhibitors (AIs) or fulvestrant; abemaciclib is also approved as a single agent. In the first-line setting, all three agents-together with an AI-substantially prolonged progression-free survival with a consistent hazard ratio of around 0.5 in all phase III trials. The data for second-line settings and beyond is also quite consistent, with again a substantial prolongation of progression-free survival demonstrated for fulvestrant together with palbociclib, ribociclib, or abemaciclib. Treatment with CDK4/6i is well tolerated and side effects are manageable. With palbociclib and ribociclib, hematological toxicities are most frequent. Abemaciclib has a lower incidence of neutropenia and a much greater incidence of all grades of diarrhea compared with other CDK4/6i, making diarrhea the key toxicity for abemaciclib. Patient quality of life is maintained under therapy and, particularly in later line settings, deterioration of quality of life is slowed down and symptoms such as pain are better controlled by CDK4/6i. Their consistent and clinically relevant efficacy makes these drugs an important improvement in our armamentarium against MBC and, potentially, ideal candidates in early breast cancer (EBC). This review summarizes the available clinical data for CDK4/6i and current research activities, particularly in EBC.

Topics: Aminopyridines; Antineoplastic Combined Chemotherapy Protocols; Benzimidazoles; Breast Neoplasms; Clinical Trials as Topic; Cyclin-Dependent Kinase 4; Cyclin-Dependent Kinase 6; Female; Humans; Molecular Targeted Therapy; Piperazines; Protein Kinase Inhibitors; Purines; Pyridines; Randomized Controlled Trials as Topic

Several endocrine therapies are available for postmenopausal women with hormone receptor-positive (HR +) advanced breast cancer (ABC). Given the absence of direct comparisons between fulvestrant and cyclin-dependent kinase 4/6 inhibitors (CDK4/6is) in combination with aromatase inhibitors (AIs), which are both used as standard first-line treatments for ABC, an indirect comparison using a network meta-analysis may be advantageous for decision making.. We performed a network meta-analysis to compare the efficacies of fulvestrant and CDK4/6is plus AIs as the first-line treatment of postmenopausal breast cancer patients.. In order to compare these treatments, we searched the PubMed, Cochrane Library, and EMBASE databases for randomized controlled trials of first-line endocrine treatment for advanced or metastatic breast cancer until October 2018. We included a total of 11 eligible trials with 5448 patients. The hazard ratios (HRs) for the efficacies of the different treatments were used as inputs in the network meta-analysis.. In the overall analysis, CDK4/6is plus AIs, including palbociclib plus letrozole, ribociclib plus letrozole, and abemaciclib plus nonsteroidal AI (letrozole or anastrozole), are all superior to 500 mg fulvestrant (HR = 0.50, 95% confidence interval [CI] 0.37-0.68; HR = 0.50, 95% CI 0.35-0.71; and HR = 0.49, 95% CI 0.34-0.71; respectively).. Within the limitations of this network meta-analysis, the comparison indicates that CDK4/6is plus AIs might represent a better option for HR+ ABC as a first-line endocrine treatment compared with fulvestrant.

Topics: Aminopyridines; Antineoplastic Combined Chemotherapy Protocols; Benzimidazoles; Biomarkers, Tumor; Breast Neoplasms; Clinical Trials as Topic; Cyclin-Dependent Kinase 4; Cyclin-Dependent Kinase 6; Female; Fulvestrant; Humans; Letrozole; Network Meta-Analysis; Piperazines; Purines; Pyridines; Receptor, ErbB-2; Receptors, Estrogen; Receptors, Progesterone

The pharmacology, clinical activity, safety, and place in therapy of the cyclin-dependent kinase (CDK) inhibitors palbociclib, ribociclib, and abemaciclib are reviewed.. CDK 4 and CDK 6 are downstream agents in the estrogen signaling pathway that control entry into the cell cycle. CDK4/6 inhibition may prevent tumor cell progression in the cell cycle. Three CDK4/6 inhibitors (palbociclib, ribociclib, and abemaciclib) are available for women with hormone receptor-positive (HR+), human epidermal growth factor receptor 2-negative (HER2-) advanced or metastatic breast cancer. These medications' indications in the treatment of HR+/HER2- advanced breast cancer include use with an aromatase inhibitor (AI) as initial therapy in postmenopausal women and with fulvestrant in women whose disease progressed during endocrine therapy. Ribociclib is also indicated as initial therapy with an AI in premenopausal or perimenopausal women and as initial therapy with fulvestrant in postmenopausal women. Abemaciclib is also indicated as monotherapy in women with disease progression after endocrine therapy and prior chemotherapy. A significant increase in progression-free survival (PFS) was seen with use of all 3 agents as initial therapy with an AI in controlled trials. Each agent also was demonstrated to produce a significant increase in PFS when used with fulvestrant in women whose disease progressed with prior endocrine therapy. Neutropenia is a dose-limiting adverse effect of palbociclib and ribociclib. Fatigue is more common with use of palbociclib and abemaciclib, and gastrointestinal effects are more common with abemaciclib use.. CDK4/6 inhibitors have significant demonstrated clinical activity in combination with AIs or fulvestrant in women with HR+/HER2- advanced or metastatic breast cancer and are becoming a standard of care in these patients.

Topics: Aminopyridines; Antineoplastic Combined Chemotherapy Protocols; Benzimidazoles; Breast Neoplasms; Cyclin-Dependent Kinase 4; Cyclin-Dependent Kinase 6; Dose-Response Relationship, Drug; Fatigue; Female; Gastrointestinal Diseases; Humans; Molecular Targeted Therapy; Neoplasm Staging; Neutropenia; Piperazines; Progression-Free Survival; Protein Kinase Inhibitors; Purines; Pyridines; Randomized Controlled Trials as Topic

Endocrine therapy is the mainstay of treatment for patients with estrogen receptor positive (ER+)/HER2-negative (HER2-) metastatic breast cancer (MBC). Many clinicians consider the sequential endocrine therapy is gold standard strategy because of better outcome and the maintenance of a better quality of life (QOL) for MBC patients. However, clinical practice shall be changed according to development of CDK4/6 inhibitor in current. CDK4/6 is key kinase which promote the cell cycle, and especially the expression of cyclin D1 and the activation of CDK4/6 to drive breast cancer proliferation. Currently positive data of several clinical trials using three CDK4/6 inhibitors (palbocilcib, ribociclib, abemaciclib) were published and primary endpoint were met in all phase III studies. Therefore, practice change of endocrine therapy has been achieved in ER positive MBC. This review will present clinical trial data, including both the efficacy and safety of CDK4/6 inhibitors for MBC, and describe the designs of the mainly ongoing clinical trials examining CDK4/6 inhibitors for the treatment of MBC and EBC.

Topics: Aminopyridines; Antineoplastic Agents; Benzimidazoles; Breast Neoplasms; Clinical Trials as Topic; Cyclin-Dependent Kinase 4; Cyclin-Dependent Kinase 6; Female; Humans; Molecular Targeted Therapy; Piperazines; Protein Kinase Inhibitors; Purines; Pyridines; Receptors, Estrogen

The emergence of cyclin-dependent kinases 4 and 6 (CDK4/6) inhibitors marked a significant advancement in the treatment of advanced breast cancer. Ribociclib is an orally bioavailable, highly selective inhibitor of CDK4/6. In combination with various endocrine therapies, ribociclib has demonstrated clinical activity as a first-line therapy for patients with HR+, HER2- advanced breast cancer, without compromising the favorable toxicity profile associated with endocrine therapy. Thus, ribociclib is now considered a new standard of care for HR+, HER2- advanced breast cancer. Areas covered: This review provides a concise overview of the preclinical and clinical development of ribociclib, including evidence of its clinical activity and safety profile when combined with endocrine therapy in HR+, HER2- advanced breast cancer. Expert commentary: CDK4/6 inhibition represents a promising treatment option for patients with HR+ metastatic breast cancer. Ribociclib significantly improved progression-free survival in patients receiving first-line endocrine therapy for HR+, HER2- advanced breast cancer. Planned and ongoing trials investigating ribociclib in combination with other endocrine therapies and in various clinical settings will help to determine the optimal treatment sequence for different patient populations.

Topics: Aminopyridines; Animals; Antineoplastic Agents; Antineoplastic Combined Chemotherapy Protocols; Breast Neoplasms; Cyclin-Dependent Kinase 4; Cyclin-Dependent Kinase 6; Drug Design; Female; Humans; Neoplasm Metastasis; Progression-Free Survival; Purines

To compare the efficacy and toxicity of the combination of cyclin-dependent kinase 4/6 (CDK 4/6) inhibitors and nonsteroidal aromatase inhibitors (AI) versus AI alone as first-line therapy for patients with advanced hormone receptor-positive breast cancer.. Phase III randomized clinical trials (RCT) were identified after a systematic review of electronic databases. A random-effect model was used to determine the pooled hazard ratio (HR) for progression-free survival (PFS) using the inverse-variance method. The Mantel-Haenszel method was used to calculate the pooled odds ratio (OR) for overall response, clinical benefit rate and treatment-related side effects. Heterogeneity was measured using the tau-squared and I. After a systematic search, three phase III RCT (n = 1827) were included. The use of CDK 4/6 inhibitors (abemaciclib, palbociclib, and ribociclib) in combination with an AI was significantly associated with longer PFS compared to the use of letrozole or anastrozole alone (HR: 0.57; 95% CI 0.50-0.65; p < 0.00001), with no significant heterogeneity among trials. Similarly, overall response rate and clinical benefit rate were higher for patients who received the combination therapy than for patients allocated to AI alone. Grade 3 or higher treatment-related side effects were more frequently reported for patients who received CDK 4/6 inhibitors (OR: 7.51; 95% CI 6.01-9.38; p < 0.00001), these included mainly neutropenia, leukopenia and anemia.. The addition of CDK 4/6 inhibitors (either abemaciclib, palbociclib, or ribociclib) to an AI (anastrozole or letrozole) significantly improved PFS, overall response rate, and clinical benefit rate in comparison with a nonsteroidal AI alone.

Topics: Aminopyridines; Antineoplastic Agents; Antineoplastic Combined Chemotherapy Protocols; Aromatase Inhibitors; Benzimidazoles; Breast Neoplasms; Clinical Trials, Phase III as Topic; Cyclin-Dependent Kinase 4; Cyclin-Dependent Kinase 6; Female; Humans; Piperazines; Postmenopause; Protein Kinase Inhibitors; Purines; Pyridines; Randomized Controlled Trials as Topic; Treatment Outcome

To determine which of the CDK4/6 inhibitors is the optimal treatment in metastatic luminal breast cancer.. A network meta-analysis using the frequentist approach and generalized pairwise modeling was computed.. The associations of aromatase inhibitor with ribociclib, palbociclib and abemaciclib were similar in efficacy. Palbociclib-based regimen was associated with significantly lower treatment discontinuation rates compared with the other approved drugs in this indication.. In the absence of direct comparative evidence, the results of this network meta-analysis represent the best available evidence for decision making in the first-line treatment of metastatic luminal breast cancer.

Topics: Aminopyridines; Antineoplastic Combined Chemotherapy Protocols; Benzimidazoles; Breast Neoplasms; Cell Cycle; Cyclin-Dependent Kinase 4; Cyclin-Dependent Kinase 6; Female; Humans; Piperazines; Purines; Pyridines

The cyclin D-cyclin-dependent kinase (CDK) 4/6-inhibitors (CDK4/6i) induce cell cycle arrest in the G1 phase what eventually can prevent the proliferation of cancer cells. The CDK4/6i have changed the landscape of treatment options for ER-positive, HER2-negative metastatic breast cancer. Currently, palbociclib, ribociclib, and abemaciclib are approved by the US Food and Drug Administration in this setting. This success encouraged the researchers to examine CDK4/6i activity in (neo)adjuvant setting. In this review, clinical data to date and ongoing clinical trials with palbociclib, ribociclib, and abemaciclib in the early breast cancer are discussed. A literature search of these topics was carried out using PubMed and data reported at international oncology meetings and clinicaltrials.gov were included. Currently, we have the early promising data from Phase II clinical trials of CDK4/6i efficacy in the neoadjuvant setting in women with HR-positive breast cancer. Moreover, there are numerous studies that are in progress today in (neo)adjuvant setting.

Topics: Aminopyridines; Antineoplastic Agents; Benzimidazoles; Breast Neoplasms; Clinical Trials as Topic; Cyclin-Dependent Kinase 4; Cyclin-Dependent Kinase 6; Female; Humans; Molecular Targeted Therapy; Piperazines; Protein Kinase Inhibitors; Purines; Pyridines; Receptor, ErbB-2; Receptors, Estrogen

Dysregulation of the cyclin dependent kinase pathway in luminal breast cancer creates a new therapeutic opportunity for estrogen receptor positive breast cancer. Initial pan-CDK inhibitors were associated with extensive toxicities but in recent years, the development of potent specific CDK inhibitors with favorable tolerability has driven renewed interests in this class of targeted therapies. Palbociclib, ribociclib and abemaciclib are specific CDK4/6 inhibitors that have been approved by the U.S. Food and Drug Administration for use in combination with endocrine therapy for women with advanced hormone receptor positive breast cancer. These three anticancer therapeutics were approved based on progression free survival benefit seen on phase III trials with the most common grade 3 treatment-related side effects being neutropenia, fatigue, nausea and diarrhea. Except for estrogen receptor positivity, no biomarkers predictive of response to CDK4/6 inhibitors have been identified to date. Based on mechanistic insights here described, CDK4/6 inhibitors are currently being explored in combination with other agents, including targeted therapies, immunotherapy and chemotherapy.

Topics: Aminopyridines; Animals; Antineoplastic Agents; Benzimidazoles; Breast Neoplasms; Cyclin-Dependent Kinase 4; Cyclin-Dependent Kinase 6; Female; Humans; Molecular Targeted Therapy; Piperazines; Protein Kinase Inhibitors; Purines; Pyridines

Deregulated cell division, resulting in aberrant cell proliferation, is one of the key hallmarks of cancer. Cyclin-dependent kinases (CDKs) play a central role in cell cycle progression in cancer, and the clinical development of the CDK4/6 inhibitors palbociclib, ribociclib, and abemaciclib has changed clinical practice in the setting of endocrine-receptor positive breast cancer. Results of pivotal phase II and III trials investigating these CDK4/6 inhibitors in patients with endocrine receptor-positive, advanced breast cancer have demonstrated a significant improvement in progression-free survival, with a safe toxicity profile. No validated biomarkers of sensitivity or resistance exist at the moment. Future development of CDK4/6 inhibitors in breast cancer should focus on the identification of predictive biomarkers, the development of drug combinations to overcome resistance, and the application of CDK4/6 inhibitors to other breast cancer subtypes.

Topics: Aminopyridines; Antineoplastic Agents; Benzimidazoles; Breast Neoplasms; Cell Proliferation; Cyclin-Dependent Kinase 4; Cyclin-Dependent Kinase 6; Drug Resistance, Neoplasm; Female; Humans; Molecular Targeted Therapy; Piperazines; Progression-Free Survival; Protein Kinase Inhibitors; Purines; Pyridines

Aberrant cellular proliferation due to dysregulation of the cyclin-dependent kinase (CDK) retinoblastoma (Rb)-pathway occurs in several cancers. Selective inhibition of CDK4/6 is an attractive target particularly in hormone-receptor positive (HR+) metastatic breast cancer (MBC), where it has transformed the treatment of these cancers in recent years. Three CDK4/6 inhibitors, palbociclib, ribociclib, and abemaciclib, have been approved for the treatment of HR+, HER2 negative (HER2-) MBC. Areas covered: We reviewed and compared the pharmacology, clinical efficacy, and toxicity profiles of the three CDK4/6 inhibitors and discussed several challenges in the use of these drugs, particularly in identifying biomarkers, optimizing dosing strategies, and finding best combinations with other therapies. Expert opinion: All three CDK4/6 inhibitors have shown remarkable efficacy when added to endocrine therapy in the treatment of HR+/HER2- MBC with consistent improvements in progression-free survival across all phase III trials. As efficacy appears similar between the drugs, differences in toxicities, dosing schedule, and monitoring requirements may influence the choice of CDK4/6 inhibitor. There is a paucity of predictive biomarkers that have been identified thus far, but a few promising biomarkers have been studied in the preclinical setting and results of ongoing clinical studies are awaited to validate their utility.

Topics: Aminopyridines; Animals; Antineoplastic Agents; Benzimidazoles; Biomarkers, Tumor; Breast Neoplasms; Cyclin-Dependent Kinase 4; Cyclin-Dependent Kinase 6; Female; Humans; Piperazines; Progression-Free Survival; Protein Kinase Inhibitors; Purines; Pyridines

Cyclin-dependent kinase (CDK) 4/6 inhibitor-based therapies have shown great promise in improving clinical outcomes for patients with hormone receptor-positive (HR+), human epidermal growth factor receptor 2-negative (HER2-) advanced breast cancer.. 1. Discuss the mode of action of the three CDK4/6 inhibitors in late clinical development: palbociclib (PD-0332991; Pfizer), ribociclib (LEE011; Novartis), and abemaciclib (LY2835219; Lilly). 2. Describe the efficacy and safety data relating to their use in HR+, HER2- advanced breast cancer. 3. Discuss the key side effects associated with CDK4/6 inhibitors along with considerations for adverse event management and patient monitoring.. Relevant information and data were assimilated from manuscripts, congress publications, and online sources.. CDK4/6 inhibitors have demonstrated improved progression-free survival in combination with endocrine therapy compared with endocrine therapy alone. The side-effect profile of each agent is described, along with implications for patient monitoring, and considerations for patient care providers and pharmacists.. Addition of a CDK4/6 inhibitor to endocrine therapy increases efficacy and delays disease progression. Insight into the unique side-effect profiles of this class of agents and effective patient monitoring will facilitate the successful use of CDK4/6 inhibitor-based therapies in the clinic.

Topics: Aminopyridines; Antineoplastic Agents; Antineoplastic Combined Chemotherapy Protocols; Benzimidazoles; Breast Neoplasms; Cyclin-Dependent Kinase 4; Cyclin-Dependent Kinase 6; Female; Humans; Liver; Molecular Targeted Therapy; Piperazines; Protein Kinase Inhibitors; Purines; Pyridines; Receptor, ErbB-2; Transcription Factors

Cyclin D-cyclin-dependent kinase (CDK) 4/6-inhibitor of CDK4/6-retinoblastoma (Rb) pathway hyperactivation is associated with hormone receptor-positive (HR+) breast cancer (BC). Ribociclib is an orally bioavailable, highly selective small molecule inhibitor of CDK4/6 that induces G1 arrest at sub-micromolar concentrations in a variety of pRb-positive cancer cells in vitro. Ribociclib is a new standard of care for metastatic HR+/HER2 negative metastatic breast cancer. Area covered: In this article, we review the preclinical and clinical development of ribociclib as well as discussing the role for novel applications of these agents outside the arena of HR-positive, HER2-negative advanced breast cancer. Expert opinion: Results of pivotal phase II and III trials investigating ribociclib in patients with advanced-stage (HR)-positive breast cancer have demonstrated a substantial improvement in progression-free survival, with a safe toxicity profile. Mechanisms of acquired resistance to CDK4/6 inhibitors are beginning to emerge and might enable rational post-CDK4/6 inhibitor therapeutic strategies to be identified. Extending the use of CDK4/6 inhibitors beyond ER-positive breast cancer is challenging, and will likely require biomarkers that are predictive of a response. The use of combination therapies to optimize CDK4/6 targeting is under development.

Topics: Aminopyridines; Antineoplastic Agents; Breast Neoplasms; Cyclin-Dependent Kinase 4; Cyclin-Dependent Kinase 6; Disease-Free Survival; Drug Resistance, Neoplasm; Female; Humans; Neoplasm Metastasis; Purines; Receptor, ErbB-2

Uncontrolled cell division is the hallmark of cancers. Full understanding of cell cycle regulation would contribute to promising cancer therapies. In particular, cyclin-dependent kinases 4/6 (CDK4/6), which are pivotal drivers of cell proliferation by combination with cyclin D, draw more and more attention. Subsequently, extensive studies were carried out to explore drugs inhibiting CDK4/6 and assess the efficacy and safety of these drugs in cancer, especially breast cancer. Due to the insuperable adverse events and the less activity observed in vivo, the drug development of the initial pan-CDK inhibitor flavopiridol was consequently discontinued, and then highly specific inhibitors were extensively researched and developed, including palbociclib (PD0332991), ribociclib (LEE011), and abemaciclib (LY2835219). Food and Drug Administration has approved palbociclib and ribociclib for the treatment of hormone receptor-positive, human epidermal growth factor receptor 2-negative advanced or metastatic breast cancer, and recent clinical trial data suggest that palbociclib significantly improved clinical outcome when combined with letrozole or fulvestrant. Besides, the favorable effects of abemaciclib on prolonging survival of breast cancer patients have also been observed in clinical trials both for single-agent and combination strategy. In this review, we outline the preclinical and clinical advancement of these three orally bioavailable and highly selective CDK4/6 inhibitors in breast cancer.

Topics: Aminopyridines; Antineoplastic Agents, Immunological; Benzimidazoles; Breast Neoplasms; Cell Cycle; Clinical Trials as Topic; Cyclin-Dependent Kinase 4; Cyclin-Dependent Kinase 6; Drug Screening Assays, Antitumor; Female; Humans; Molecular Targeted Therapy; Neoplasm Proteins; Piperazines; Purines; Pyridines; Therapies, Investigational

Cyclin-dependent kinase 4 and 6 (CDK4/6) inhibitors such as palbociclib and ribociclib are associated with distinct adverse effects (AEs) compared to other targeted therapies. This meta-analysis of clinical trials summarizes these agents' toxicity profile.. A librarian-guided literature search was conducted in March of 2017. The trials needed to have at least one of the study arms consisting of palbociclib or ribociclib monotherapy at currently FDA approved dose regimens. Heterogeneity across studies was analyzed using I. Seven randomized trials and 1,332 patients were included in our meta-analysis. There was evidence of significant heterogeneity between studies for serious AEs but not for death. The pooled absolute risk (AR) for all-causality serious AEs and treatment-related death were 16% and 0%, respectively. Patients treated with CDK 4/6 inhibitors had an AR of grade 3/4 neutropenia of 61%; neutropenic fever and infections were rare (1% and 3%, respectively). Grade 3/4 nausea, vomiting, and rash were rare. There was no significant correlation between age of patients at study entry and the risk of grade 3/4 neutropenia.. Treatment with CDK 4/6 inhibitors is well tolerated and associated with a low risk of treatment-related deaths. There is an increased AR of grade 3/4 neutropenia but a low AR of associated infections.

Topics: Aminopyridines; Antineoplastic Agents; Breast Neoplasms; Disease-Free Survival; Dose-Response Relationship, Drug; Female; Humans; Molecular Targeted Therapy; Neutropenia; Piperazines; Purines; Pyridines

Resistance to endocrine treatment generally occurs over time, especially in the metastatic stage. In this paper, we aimed to review the mechanisms of cyclin-dependent kinase (CDK) 4/6 inhibition and clinical usage of new agents in the light of recent literature updates.. A literature search was carried out using PubMed, Medline and ASCO and ESMO annual-meeting abstracts by using the following search keywords; "palbociclib", "abemaciclib", "ribociclib", "cyclin-dependent kinase inhibitors" and "CDK 4/6" in metastatic breast cancer (MBC). The last search was on 10 June 2017.. CDKs and cyclins are two molecules that have a key role in cell cycle progression. Today, there are three highly selective CDK4/6 inhibitors in clinical development - palbociclib, ribociclib and abemaciclib. Palbociclib and ribociclib were recently approved by the US FDA in combination with letrozole for the treatment of MBC in a first-line setting, as well as palbociclib in combination with fulvestrant for hormone-receptor (HR)-positive MBC that had progressed while on previous endocrine therapy according to the PALOMA-1, MONALEESA-2 and PALOMA-3 trials, respectively. In the recently published randomized phase III MONARCH 2 trial, abemaciclib plus letrozole had longer progression-free survival and higher objective response rates with less serious adverse events in advanced HR-positive breast cancer previously treated with hormonal treatment.. CDK4/6 inhibition is a new and promising target for patients with hormone-receptor-positive MBC. Both palbociclib and ribociclib showed significant additive benefit for patients receiving first-line treatment for HR-positive, epidermal growth factor receptor-2-negative advanced breast cancer. Palbociclib and abemaciclib also had significant activity in combination with fulvestrant for patients with MBC that progressed on previous endocrine therapy.

Topics: Aminopyridines; Antineoplastic Combined Chemotherapy Protocols; Benzimidazoles; Breast Neoplasms; Cyclin-Dependent Kinase 4; Disease-Free Survival; Estradiol; Female; Fulvestrant; Humans; Letrozole; Nitriles; Piperazines; Protein Kinase Inhibitors; Purines; Pyridines; Randomized Controlled Trials as Topic; Triazoles

Aberrations of the cell cycle are pervasive in cancer, and selective cell cycle inhibition of cancer cells is a target of choice for a number of novel cancer therapeutics. Cyclin-dependent kinases (CDKs) are key regulatory enzymes that control cell cycle transitions and the commitment to cell division. Palbociclib and ribociclib are both orally active, highly selective reversible inhibitors of CDK4 and CDK6 that are approved by the U.S. Food and Drug Administration (FDA) for hormone receptor-positive metastatic breast cancer in combination with specific endocrine therapies. A third oral CDK4/6 inhibitor, abemaciclib, received Breakthrough Therapy designation status from the FDA and is also being developed in breast cancer. The most common adverse events associated with palbociclib and ribociclib are hematologic, particularly neutropenia. However, the neutropenia associated with CDK4/6 inhibitors is distinct from chemotherapy-induced neutropenia in that it is rapidly reversible, reflecting a cytostatic effect on neutrophil precursors in the bone marrow. Most hematologic abnormalities seen with CDK4/6 inhibitors are not complicated and are adequately managed with standard supportive care and dose adjustments when indicated. Cytopenias are less prevalent with abemaciclib, although fatigue and gastrointestinal toxicity is more common with this agent. This review focuses on the clinical management of potential toxicities and drug interactions seen with the use of CDK4/6 inhibitors in breast cancer, with a focus on palbociclib and ribociclib, and summarizes practical management strategies for an oncologist.. The emergence of modern cyclin-dependent kinase (CDK) inhibitors has changed the treatment paradigm for metastatic hormone receptor (HR)-positive breast cancer. Palbociclib, ribociclib, and abemaciclib are highly selective reversible inhibitors of CDK4 and CDK6. Palbociclib is U.S. Food and Drug Administration (FDA)-approved in the first- and second-line settings in combination with endocrine therapy for HR-positive metastatic breast cancer. Ribociclib is FDA-approved in the first-line setting. Abemaciclib has received FDA Breakthrough Therapy designation status. This review focuses on the clinical management of potential toxicities and drug interactions seen with the use of CDK4/6 inhibitors in breast cancer.

Topics: Aminopyridines; Benzimidazoles; Breast Neoplasms; Cell Cycle; Clinical Trials as Topic; Cyclin-Dependent Kinase 4; Cyclin-Dependent Kinase 6; Drug Interactions; Female; Humans; Molecular Targeted Therapy; Neutropenia; Piperazines; Protein Kinase Inhibitors; Purines; Pyridines

The cyclin D-cyclin dependent kinase (CDK) 4/6-inhibitor of CDK4 (INK4)-retinoblastoma (Rb) pathway plays a crucial role in cell cycle progression and its dysregulation is an important contributor to endocrine therapy resistance. CDK4/6 inhibitors trigger cell cycle arrest in Rb protein (pRb)-competent cells. Recent years have seen the development of selective CDK4/6 inhibitors, which have delivered promising results of efficacy and manageable safety profiles. The main objective of this review is to discuss preclinical and clinical data to date, and ongoing clinical trials with palbociclib, ribociclib, and abemaciclib in breast cancer.. A literature search of above topics was carried out using PubMed and data reported at international oncology meetings and clinicaltrials.gov were included.. The highly selective oral CDK4/6 inhibitors have been tested in combination with endocrine therapy in Phase III studies in metastatic breast cancer. Results led to the US Food and Drug Administration approval of palbociclib (PD0332991) and ribociclib (LEE011), and abemaciclib (LY2835219) is in development. Studies of these agents, in combination with endocrine therapy, are also underway in ER-positive early breast cancer in the neoadjuvant and adjuvant settings. Moreover, they are also being investigated with other agents in the advanced setting and in triple negative breast cancer.. After having demonstrated impressive activity in ER-positive, HER2-negative metastatic breast cancer, currently CDK4/6 inhibitors are in further development. It is obvious that this class of agents with their efficacy, low and easily manageable toxicity, and oral dosage is a very important treatment option for breast cancer patients.

Topics: Aminopyridines; Antineoplastic Agents; Benzimidazoles; Biomarkers, Tumor; Breast Neoplasms; Clinical Trials as Topic; Cyclin-Dependent Kinase 4; Cyclin-Dependent Kinase 6; Female; Humans; Molecular Targeted Therapy; Neoplasm Metastasis; Neoplasm Staging; Piperazines; Protein Kinase Inhibitors; Purines; Pyridines; Randomized Controlled Trials as Topic; Treatment Outcome

CDK4/6 inhibitors are a promising new class of drugs for hormone-receptor-positive breast cancer and have been shown to overcome and delay hormone resistance in advanced breast cancer. Ribociclib, a selective oral inhibitor of CDK4/6, was approved by the US FDA for first-line treatment of hormone-receptor-positive/HER2-negative metastatic breast cancer. This review summarizes the clinical evidence available for ribociclib, from preclinical data to the pivotal studies, with a special focus on toxicity and its management. In addition, this article reviews potential new combinations under study, as well as ongoing clinical trials both in the metastatic and early setting. Finally, this review compares ribociclib activity and toxicity with those of the drugs of the same class (palbociclib and abemaciclib).

Topics: Aminopyridines; Animals; Antineoplastic Agents; Antineoplastic Combined Chemotherapy Protocols; Breast Neoplasms; Clinical Trials as Topic; Cyclin-Dependent Kinase 4; Cyclin-Dependent Kinase 6; Drug Evaluation, Preclinical; Female; Humans; Molecular Targeted Therapy; Neoplasm Metastasis; Neoplasm Staging; Protein Kinase Inhibitors; Purines; Receptor, ErbB-2; Receptors, Estrogen; Receptors, Progesterone

A burst of recent activity has surrounded the study of cyclin-dependent kinase 4/6 (CDK 4/6) inhibitors for the treatment of metastatic breast cancer. The success of these drugs in the metastatic setting has pushed the evaluation of these agents in early-stage disease. The use of CDK 4/6 inhibitors as neoadjuvant and adjuvant therapy is a hot topic and several studies are underway.. Ongoing studies are exploring the addition of CDK 4/6 inhibitors to endocrine therapy in early breast cancer.. Identification of the optimal treatment combinations is the goal of current research. Finding biomarkers for patients' selection will be the goal of future research.

Topics: Aminopyridines; Antineoplastic Agents; Benzimidazoles; Breast Neoplasms; Chemotherapy, Adjuvant; Cyclin-Dependent Kinase 4; Cyclin-Dependent Kinase 6; Female; Humans; Neoadjuvant Therapy; Piperazines; Protein Kinase Inhibitors; Purines; Pyridines; Randomized Controlled Trials as Topic

The introduction of CDK4/6 inhibitors, such as ribociclib, has changed the treatment landscape for post-menopausal women with HR+/HER2- advanced or metastatic breast cancer. As first-line treatment of HR+/HER2- MBC, the addition of a CDK4/6 inhibitor to an aromatase inhibitor improves progression-free survival compared to an aromatase inhibitor alone. Areas covered: In this drug profile, we review the current market for HR+/HER2- MBC, as well as the characteristics, mechanism, pharmacology, pharmacodynamics, pharmacokinetics, metabolism, clinical efficacy, toxicities, monitoring, and dosing modification of the CDK4/6 inhibitor ribociclib. Expert commentary: CDK4/6 inhibitors, such as ribociclib, improve outcomes in post-menopausal women with HR+/HER2- MBC. The most common toxicity of ribociclib is neutropenia, which is generally not complicated and can be managed with dose modification and/or supportive care measures. Additional research will help better define the optimal clinical use of ribociclib.

Topics: Aminopyridines; Antineoplastic Agents; Breast Neoplasms; Cyclin-Dependent Kinase 4; Cyclin-Dependent Kinase 6; Disease-Free Survival; Dose-Response Relationship, Drug; Female; Humans; Neoplasm Metastasis; Neutropenia; Postmenopause; Purines; Receptor, ErbB-2

Topics: Aminopyridines; Antineoplastic Combined Chemotherapy Protocols; Benzimidazoles; Breast Neoplasms; Cyclin-Dependent Kinases; Estradiol; Female; Fulvestrant; Humans; Letrozole; Nitriles; Piperazines; Protein Kinase Inhibitors; Purines; Pyridines; Randomized Controlled Trials as Topic; Receptor, ErbB-2; Receptors, Estrogen; Risk Assessment; Triazoles

Dysregulated cellular proliferation, one of the hallmarks of cancer, is mediated by aberrant activation of the cell cycle machinery through the biological effects of cyclin-dependent kinases (CDKs). The clinical development of non-selective CDK inhibitors failed due to combined lack of efficacy and excessive toxicity reported by clinical trials across different cancer types. The clinical development of second generation, CDK4/6-selective inhibitors, namely palbociclib, abemaciclib and ribociclib, led to practice-changing results in the setting of breast cancer. Areas covered: This review illustrates how CDK4/6-selective inhibitors got approval for the treatment of patients with either newly diagnosed or pretreated advanced hormone receptor positive, HER2-negative breast cancer. Furthermore, data about potential predictive biomarkers, as well as preclinical and preliminary clinical evidence for potential antitumor activity of CDK4/6 inhibition in other breast cancer subtypes is provided. Expert opinion: Future clinical development of CDK4/6 inhibitors in breast cancer will focus on the following aspects: i) optimization of treatment sequencing for patients with advanced disease, ii) early-stage disease, iii) other subtypes of breast cancer in rationally chosen therapeutic combinations and iv) the identification of predictive biomarkers.

Topics: Aminopyridines; Animals; Antineoplastic Agents; Benzimidazoles; Breast Neoplasms; Cell Proliferation; Cyclin-Dependent Kinase 4; Cyclin-Dependent Kinase 6; Drug Design; Female; Humans; Neoplasm Staging; Piperazines; Protein Kinase Inhibitors; Purines; Pyridines

Cyclin dependent kinase (CDK) 4/6 inhibitors have advanced the treatment of metastatic breast cancer by targeting the cell cycle machinery, interrupting intracellular and mitogenic hormone signals that stimulate proliferation of malignant cells. Preclinical evidence demonstrated that derangements of cyclin D1, CDK4/6, and retinoblastoma expression are common in breast cancer, and suggested a therapeutic benefit from interrupting this axis required for cell cycle progression. Studies of cell lines and animal models of breast cancer have demonstrated the complex interplay between the cell cycle and estrogen receptor and human epidermal growth receptor 2 signaling, which informs our understanding of synergistic use of CDK4/6 inhibitors with endocrine therapy, as well as mechanisms of resistance to endocrine therapy. Interestingly, estrogen receptor activity leads to upregulation of cyclin D1 expression, but the estrogen receptor is also in turn activated by cyclin D1, independent of estrogen binding. Early CDK inhibitors were nonspecific and limited by systemic toxicities, while the current generation of CDK4/6 inhibitors have shown promise in the treatment of hormone receptor-positive breast cancer. Preclinical investigations of the three CDK4/6 inhibitors approved by the US Food and Drug Administration (palbociclib, ribociclib, and abemaciclib) lend further insight into their mechanism of action, which will hopefully inform the future use and refinement of these therapies. Finally, we summarize evidence for additional novel CDK4/6 inhibitors currently in development.

Topics: Aminopyridines; Antineoplastic Agents, Hormonal; Benzimidazoles; Breast Neoplasms; Cyclin-Dependent Kinase 4; Cyclin-Dependent Kinase 6; Drug Synergism; Humans; Molecular Targeted Therapy; Piperazines; Protein Kinase Inhibitors; Purines; Pyridines; Receptor, ErbB-2; Receptors, Estrogen

With 40,920 American women expected to die from breast cancer in 2018 and global health estimates that more than 508,000 women died in 2011 from this disease, the identification of novel therapeutic strategies for the treatment of breast cancer cannot be ignored. A breakthrough class of cancer drugs that has emerged in recent years and has had an impact in the treatment of breast cancer are the cyclin-dependent kinase 4 and 6 (CDK4/6) inhibitors, with palbociclib the first in class to have received regulatory approval for breast cancer. In this article we will compare and contrast three CDK4/6 inhibitors - palbociclib, ribociclib and abemaciclib - that have received regulatory approval for the treatment of metastatic breast cancer. Ribociclib and abemaciclib developed after the success of palbociclib represent examples of "me-too" therapies increasingly being deployed in oncology.

Topics: Aminopyridines; Benzimidazoles; Breast Neoplasms; Cyclin-Dependent Kinase 4; Cyclin-Dependent Kinase 6; Humans; Molecular Targeted Therapy; Piperazines; Protein Kinase Inhibitors; Purines; Pyridines

For millions of women, breast cancer remains a potentially life-endangering diagnosis. With advances in research, new therapies targeted to tumor biology are emerging to treat the most common form of this disease. Cyclin-dependent kinase (CDK) 4/6 inhibitors are a new class of therapeutic agents that have the potential to improve the outcomes of patients with hormone receptor-positive (HR(+)) breast cancer. Three CDK 4/6 inhibitors have been investigated for the treatment of HR(+) breast cancer, including palbociclib (PD 0332991), ribociclib (LEE011), and abemaciclib (LY2835219). Palbociclib recently received accelerated Food and Drug Administration approval for the treatment of HR(+) metastatic breast cancer in combination with letrozole, and recent data suggest improved outcome when combined with fulvestrant. In this article, the mechanism of action of CDK 4/6 inhibitors, preclinical studies on their efficacy, ongoing clinical trials in breast cancer, and toxicity profiles are reviewed.

Topics: Aminopyridines; Antineoplastic Agents; Benzimidazoles; Breast Neoplasms; Cyclin-Dependent Kinase 4; Cyclin-Dependent Kinase 6; Female; Humans; Piperazines; Protein Kinase Inhibitors; Purines; Pyridines

In this article, we not only review the preclinical and clinical studies of cyclin-dependent kinase (CDK) 4/6 inhibitors in breast cancer, liposarcoma, mantel cell lymphoma, melanoma and germ cell tumors, but also examine promising preclinical data in glioblastoma, renal and ovarian cancer models that may provide directions for future development.. Targeting CDKs has been the focus of considerable basic science and clinical research. The CDK 4/6 inhibitors are a novel class of therapeutics that target the CDK 4/6 kinases that promote transition through the cell cycle. Currently, palbociclib (PD0332991, Pfizer), abemaciclib (LY2835219, Lilly) and ribociclib (LEE011, Novartis) are being investigated in clinical trials. These oral agents offer the hope of clinical efficacy in many tumor types, and have been associated with minimal toxicity. Amplification/overexpression of cyclin D, loss of CDKN2A (p16) and amplification/overexpression of CDK4 are proposed biomarkers of improved response to CDK4/6 inhibition.. Palbociclib, abemaciclib and ribociclib have demonstrated very promising clinical activity in breast cancer, liposarcoma, mantel cell lymphoma and melanoma. Moreover, CDK4/6 inhibitors have shown promising preclinical activity in glioblastoma, renal and ovarian cancer models that may provide directions for their future clinical development. Further preclinical and clinical research is needed to better understand mechanisms of resistance and develop rational combination therapies with other targeted agents.

Topics: Aminopyridines; Antineoplastic Agents; Antineoplastic Combined Chemotherapy Protocols; Breast Neoplasms; Cell Cycle; Cyclin-Dependent Kinase 4; Cyclin-Dependent Kinase 6; Female; Humans; Liposarcoma; Lymphoma, Mantle-Cell; Melanoma; Neoplasms, Germ Cell and Embryonal; Piperazines; Protein Kinase Inhibitors; Purines; Pyridines; Signal Transduction

Uncontrolled cellular proliferation, mediated by dysregulation of the cell-cycle machinery and activation of cyclin-dependent kinases (CDKs) to promote cell-cycle progression, lies at the heart of cancer as a pathological process. Clinical implementation of first-generation, nonselective CDK inhibitors, designed to inhibit this proliferation, was originally hampered by the high risk of toxicity and lack of efficacy noted with these agents. The emergence of a new generation of selective CDK4/6 inhibitors, including ribociclib, abemaciclib and palbociclib, has enabled tumour types in which CDK4/6 has a pivotal role in the G1-to-S-phase cell-cycle transition to be targeted with improved effectiveness, and fewer adverse effects. Results of pivotal phase III trials investigating palbociclib in patients with advanced-stage oestrogen receptor (ER)-positive breast cancer have demonstrated a substantial improvement in progression-free survival, with a well-tolerated toxicity profile. Mechanisms of acquired resistance to CDK4/6 inhibitors are beginning to emerge that, although unwelcome, might enable rational post-CDK4/6 inhibitor therapeutic strategies to be identified. Extending the use of CDK4/6 inhibitors beyond ER-positive breast cancer is challenging, and will likely require biomarkers that are predictive of a response, and the use of combination therapies in order to optimize CDK4/6 targeting.

Topics: Aminopyridines; Antineoplastic Combined Chemotherapy Protocols; Benzimidazoles; Breast Neoplasms; Cell Cycle; Clinical Trials as Topic; Cyclin D1; Cyclin-Dependent Kinase 4; Cyclin-Dependent Kinase 6; Female; Forecasting; Humans; Molecular Targeted Therapy; Neoplasms; Piperazines; Purines; Pyridines

Breast cancer remains a major cause of morbidity and mortality worldwide. Given the central role of cyclin-dependent kinases in regulating cell division, there has been a longstanding interest in developing compounds which target the cyclin D1: CDK4/6 axis in breast cancer. The recent discovery of potent and selective CDK4/6 inhibitors (CDK4/6i) was an important breakthrough.. There are three CDK4/6i in clinical development (palbociclib, ribociclib and abemaciclib). Phase II and III studies using palbociclib in combination with endocrine therapy demonstrated remarkable clinical activity in women with hormone receptor (HR)-positive, human epidermal growth factor receptor 2 (HER2)-negative advanced breast cancer, resulting in two separate FDA approvals in 2015 and 2016. In this article, we review the preclinical and clinical development of these compounds as well as discussing the role for novel applications of these agents outside the arena of HR-positive, HER2-negative advanced breast cancer.. In combination with endocrine therapy, CDK4/6i have shown promising efficacy in patients with advanced HR-positive, HER2-negative advanced breast cancer. Numerous trials in a variety of clinical settings and in different tumor types are ongoing or planned.

Topics: Aminopyridines; Benzimidazoles; Breast Neoplasms; Clinical Trials as Topic; Cyclin-Dependent Kinase 4; Cyclin-Dependent Kinase 6; Female; Humans; Piperazines; Protein Kinase Inhibitors; Purines; Pyridines; Receptor, ErbB-2

Dysregulation of the cell cycle is a classic hallmark of cancer growth and metastatic potential. Re-establishing cell cycle control through CDK inhibition has emerged as an attractive option in the development of targeted cancer therapy. Three oral agents selectively targeting CDK4/6 have been developed: palbociclib, abemaciclib, and LEE011. Preclinical models show optimal activity in hormone receptor positive breast cancer, which may display biologic features suggesting particular dependence on the CDK4/cyclin D1/Rb interaction. Palbociclib has been studied in a randomized phase 2 clinical trial in metastatic hormone receptor positive breast cancer in which the combination of palbociclib and endocrine therapy significantly prolonged progression-free survival over endocrine therapy alone. The toxicity profile of palbociclib and the other CDK 4/6 inhibitors in early phase I and II trials has been predominantly hematologic, characterized by limited neutropenia, as well as variable gastrointestinal toxicity. Multiple phase II and III studies are ongoing with all three agents, and are designed to explore the role of CDK 4/6 inhibition in metastatic hormone receptor positive breast cancer. The next wave of studies will examine further clinical and scientific topics, including the role of CDK 4/6 inhibition in the neo/adjuvant setting, the combination of CDK 4/6 inhibitors with other targeted therapies, and the activity of CDK 4/6 inhibitors in the HER2 positive subset of breast cancer, as well as in other cancer subtypes. Should ongoing study confirm benefits and tolerability of CDK 4/6 inhibition, combination therapy with endocrine agents may become a new standard of care for hormone receptor positive breast cancer.

Topics: Aminopyridines; Antineoplastic Agents; Antineoplastic Combined Chemotherapy Protocols; Benzimidazoles; Breast Neoplasms; Cell Cycle; Clinical Trials as Topic; Cyclin-Dependent Kinase 4; Cyclin-Dependent Kinase 6; Female; Humans; Piperazines; Protein Kinase Inhibitors; Purines; Pyridines

Imbalance of the cyclin D and cyclin-dependent kinase (CDK) pathway in cancer cells may result in diversion away from a pathway to senescence and toward a more proliferative phenotype. Cancer cells may increase cyclin D-dependent activity through a variety of mechanisms. Therapeutic inhibition of CDKs in tumors to negate their evasion of growth suppressors has been identified as a key anticancer strategy. In this review, we outline the development of CDK inhibitory therapy in breast cancer, including the initial experience with the pan-CDK inhibitor flavopiridol and the next generation of oral highly selective CDK4 and CDK6 inhibitors PD0332991 (palbociclib), LEE011 (ribociclib), and LY2835219 (abemaciclib). Data from phase I and II studies in estrogen receptor-positive (ER+) breast cancer demonstrate promising efficacy with manageable toxic effects, chiefly neutropenia. We discuss these studies and the phase III studies that are accruing or nearing completion. We describe the application of such therapy to other breast cancer settings, including HER2-positive breast cancer and the adjuvant treatment of early breast cancer. We also discuss potential concerns surrounding the combination of CDK inhibitors with chemotherapy and their effects on repair of double-strand DNA breaks in cancer cells. Oral highly selective CDK inhibitors show great promise in improving the outcomes of patients with ER+ breast cancer, although caution must apply to their combination with other agents and in the early breast cancer setting.

Topics: Aminopyridines; Breast Neoplasms; Cell Cycle; Clinical Trials as Topic; Cyclin-Dependent Kinase 4; Cyclin-Dependent Kinase 6; DNA Breaks, Double-Stranded; Estrogen Receptor alpha; Female; Flavonoids; Humans; Piperazines; Piperidines; Protein Kinase Inhibitors; Purines; Pyridines

Renal impairment is common in patients with cancer and can alter the PK and thus the safety and efficacy of drugs. We assessed the impact of renal impairment during treatment with ribociclib, a cyclin-dependent kinase 4/6 inhibitor, and determined dose recommendations for patients with advanced breast cancer with renal impairment.. A comprehensive assessment integrating pharmacokinetic, safety, and efficacy data from a phase I dedicated renal impairment study in non-cancer subjects and six phase I-III trials in patients with cancer was performed.. Ribociclib showed higher pharmacokinetic exposure in subjects with renal impairment than those with normal renal function following a single 400-mg dose in the dedicated renal impairment study. However, in patient trials, both single-dose and steady‑state ribociclib exposure was comparable between patients with cancer with mild/moderate renal impairment and those with normal renal function following the recommended starting dose of 600 mg. Model-predicted steady‑state exposure in patients with advanced breast cancer was also similar across the renal function groups. Progression-free survival was similar and safety profiles were generally consistent across the renal cohorts (normal/mild/moderate) in patients with advanced breast cancer, with low-grade and manageable adverse events, demonstrating a positive benefit-risk profile.. From the collective evidence and considering a real-world clinical setting, no dose adjustment is recommended for patients with mild/moderate renal impairment, whereas a reduced dose is recommended for patients with severe renal impairment. This report presented a holistic and innovative strategy to determine dose in patients with renal impairment and demonstrated the effectiveness of integrating the data of both a clinical pharmacology study and patient trials to justify doses in patients with renal impairment.. Clinicaltrials.gov identifiers: NCT02431481, NCT01958021, NCT02422615, NCT02278120, NCT01237236, NCT01898845, NCT01872260.

Topics: Aminopyridines; Antineoplastic Combined Chemotherapy Protocols; Breast Neoplasms; Female; Humans; Purines; Renal Insufficiency

Thymidine kinase 1 (TK1) is an enzyme downstream of the CDK4/6 pathway, with a critical role in DNA synthesis; serum TK1 activity (sTKa) is a novel liquid biopsy biomarker of tumour cell proliferation.. The phase IIIb, BioItaLEE trial (NCT03439046) collected sera from postmenopausal patients with hormone receptor-positive (HR+), HER2-negative (HER2-) advanced breast cancer (ABC) treated with first-line ribociclib plus letrozole at baseline, day 15 of cycle 1 (C1D15), day 1 of cycle 2 (C2D1), and at first imaging. Associations between sTKa assessed at different time points or sTKa dynamic patterns, and progression-free survival (PFS) were evaluated using multivariate Cox models.. Overall, 287 patients were enroled. Median follow-up was 26.9 months. High sTKa (>median) at baseline was associated with higher risk of progression (hazard ratio [HR], 2.21; 95% confidence interval [95% CI], 1.45, 3.37; P = 0.0002); similar results were observed for patients with high sTKa levels at C1D15 and C2D1. Early sTKa dynamic patterns were strongly predictive of PFS. The pattern with high sTKa levels at C2D1 following initial decrease at C1D15 was associated with higher risk of progression versus the pattern with low sTKa levels at both time points (HR, 2.89; 95% CI, 1.57, 5.31; P = 0.0006), while the pattern with high sTKa levels at C1D15 was associated with the shortest PFS (HR, 5.65; CI: 2.84, 11.2; P < 0.0001). Baseline and dynamic sTKa changes provided independent information.. sTKa appears to be a new promising prognostic and pharmacodynamic biomarker in patients with HR+/HER2- ABC treated with ribociclib plus letrozole as first-line therapy.

Topics: Aminopyridines; Antineoplastic Combined Chemotherapy Protocols; Aromatase Inhibitors; Biomarkers; Breast Neoplasms; Female; Humans; Letrozole; Proportional Hazards Models; Prospective Studies; Receptor, ErbB-2; Thymidine Kinase

Cyclin-dependent kinase 4/6 inhibitor (CDK4/6i) with endocrine therapy (ET) improves progression-free survival (PFS) and overall survival (OS) in hormone receptor-positive (HR+), human epidermal growth factor receptor 2-negative (HER2-) metastatic breast cancer (MBC). Although preclinical and clinical data demonstrate a benefit in changing ET and continuing a CDK4/6i at progression, no randomized prospective trials have evaluated this approach.. In this investigator-initiated, phase II, double-blind placebo-controlled trial in patients with HR+/HER2- MBC whose cancer progressed during ET and CDK4/6i, participants switched ET (fulvestrant or exemestane) from ET used pre-random assignment and randomly assigned 1:1 to the CDK4/6i ribociclib versus placebo. PFS was the primary end point, defined as time from random assignment to disease progression or death. Assuming a median PFS of 3.8 months with placebo, we had 80% power to detect a hazard ratio (HR) of 0.58 (corresponding to a median PFS of at least 6.5 months with ribociclib) with 120 patients randomly assigned using a one-sided log-rank test and significance level set at 2.5%.. Of the 119 randomly assigned participants, 103 (86.5%) previously received palbociclib and 14 participants received ribociclib (11.7%). There was a statistically significant PFS improvement for patients randomly assigned to switched ET plus ribociclib (median, 5.29 months; 95% CI, 3.02 to 8.12 months) versus switched ET plus placebo (median, 2.76 months; 95% CI, 2.66 to 3.25 months) HR, 0.57 (95% CI, 0.39 to 0.85);. In this randomized trial, there was a significant PFS benefit for patients with HR+/HER2- MBC who switched ET and received ribociclib compared with placebo after previous CDK4/6i and different ET.

Topics: Antineoplastic Combined Chemotherapy Protocols; Breast Neoplasms; Cyclin-Dependent Kinase 4; Cyclin-Dependent Kinase 6; Double-Blind Method; Female; Humans; Prospective Studies; Receptor, ErbB-2

The Dutch Drug Rediscovery Protocol (DRUP) and the Australian Cancer Molecular Screening and Therapeutic (MoST) Program are similar nonrandomized, multidrug, pan-cancer trial platforms that aim to identify signals of clinical activity of molecularly matched targeted therapies or immunotherapies outside their approved indications. Here, we report results for advanced or metastatic cancer patients with tumors harboring cyclin D-CDK4/6 pathway alterations treated with CDK4/6 inhibitors palbociclib or ribociclib. We included adult patients that had therapy-refractory solid malignancies with the following alterations: amplifications of CDK4, CDK6, CCND1, CCND2 or CCND3, or complete loss of CDKN2A or SMARCA4. Within MoST, all patients were treated with palbociclib, whereas in DRUP, palbociclib and ribociclib were assigned to different cohorts (defined by tumor type and alteration). The primary endpoint for this combined analysis was clinical benefit, defined as confirmed objective response or stable disease ≥16 weeks. We treated 139 patients with a broad variety of tumor types; 116 with palbociclib and 23 with ribociclib. In 112 evaluable patients, the objective response rate was 0% and clinical benefit rate at 16 weeks was 15%. Median progression-free survival was 4 months (95% CI: 3-5 months), and median overall survival 5 months (95% CI: 4-6 months). In conclusion, only limited clinical activity of palbociclib and ribociclib monotherapy in patients with pretreated cancers harboring cyclin D-CDK4/6 pathway alterations was observed. Our findings indicate that monotherapy use of palbociclib or ribociclib is not recommended and that merging data of two similar precision oncology trials is feasible.

Topics: Aminopyridines; Australia; Breast Neoplasms; Cyclin D; Cyclin-Dependent Kinase 4; Cyclin-Dependent Kinase 6; Cyclins; DNA Helicases; Female; Humans; Neoplasms; Nuclear Proteins; Precision Medicine; Protein Kinase Inhibitors

There is increasing interest in the use of liquid biopsies, but data on longitudinal analyses of circulating tumor DNA (ctDNA) remain relatively limited. Here, we report a longitudinal ctDNA analysis of MONALEESASIA, a phase Ib trial evaluating the efficacy and safety of ribociclib plus endocrine therapy (ET) in Asian patients with hormone receptor-positive, human epidermal growth factor receptor-2-negative advanced breast cancer.. MONALEESASIA enrolled premenopausal and postmenopausal Japanese and postmenopausal non-Japanese Asian patients. All patients received ribociclib with ET (letrozole, fulvestrant, or tamoxifen with goserelin). ctDNA was analyzed using a targeted next-generation sequencing panel of 572 cancer-related genes and correlated by best overall response (BOR).. Five hundred seventy-four cell-free DNA samples from 87 patients were tested. The most frequently altered genes at baseline included PIK3CA (29%) and TP53 (22%). Treatment with ribociclib plus ET decreased ctDNA in most patients at the first on-treatment time point, regardless of dose or ET partner. Patients with partial response and stable disease had lower ctDNA at baseline that remained low until data cutoff if no progressive disease occurred. Most patients with progressive disease as the best response had higher ctDNA at baseline that remained high at the end of treatment. For patients with partial response and stable disease with subsequent progression, ctDNA increased towards the end of treatment in most patients, with a median lead time of 83 days (14-309 days). In some patients with BOR of partial response who experienced disease progression later, specific gene alterations and total ctDNA fraction increased; this was sometimes observed concurrently with the development of new lesions without a change in target lesion size. Patients with alterations in PIK3CA and TP53 at baseline had shorter median progression-free survival compared with patients with wild-type PIK3CA and TP53, 12.7 and 7.3 months vs 19.2 and 19.4 months, respectively (P = .016 and P = .0001, respectively).. Higher ctDNA levels and PIK3CA and TP53 alterations detected at baseline were associated with inferior outcomes. On-treatment ctDNA levels were associated with different patterns based on BOR. Longitudinal tracking of ctDNA may be useful for monitoring tumor status and detection of alterations with treatment implications.. ClinicalTrials.gov NCT02333370 . Registered on January 7, 2015.

Topics: Aminopyridines; Antineoplastic Combined Chemotherapy Protocols; Breast Neoplasms; Class I Phosphatidylinositol 3-Kinases; Female; Humans; Receptor, ErbB-2

The phase III MONALEESA-3 trial included first- (1L) and second-line (2L) patients and demonstrated a significant overall survival (OS) benefit for ribociclib + fulvestrant in patients with hormone receptor-positive, human epidermal growth factor receptor 2-negative (HR+/HER2-) advanced breast cancer (ABC) in the final protocol-specified and exploratory (longer follow-up) OS analyses. At the time of these analyses, the full OS benefit of 1L ribociclib was not completely characterized because the median OS (mOS) was not reached. As CDK4/6 inhibitor (CDK4/6i) + endocrine therapy (ET) is now a preferred option for 1L HR+/HER2- ABC, we report an exploratory analysis (median follow-up, 70.8 months; 14.5 months longer than the prior analysis) to fully elucidate the OS benefit in the MONALEESA-3 1L population.. Postmenopausal patients with HR+/HER2- ABC were randomized 2:1 to 1L/2L fulvestrant + ribociclib or placebo. OS in 1L patients (de novo disease or relapse > 12 months from completion of [neo]adjuvant ET) was assessed by Cox proportional hazards model and Kaplan-Meier methods. Progression-free survival 2 (PFS2) and chemotherapy-free survival (CFS) were analyzed. MONALEESA-3 is registered with ClinicalTrials.gov (NCT02422615).. At data cutoff (January 12, 2022; median follow-up time, 70.8 months), mOS was 67.6 versus 51.8 months with 1L ribociclib versus placebo (hazard ratio (HR) 0.67; 95% CI 0.50-0.90); 16.5% and 8.6% of ribociclib and placebo patients, respectively, were still receiving treatment. PFS2 (HR 0.64) and CFS (HR 0.62) favored ribociclib versus placebo. Among those who discontinued treatment, 16.7% and 35.0% on ribociclib or placebo, respectively, received a subsequent CDK4/6i. No new safety signals were observed.. This analysis of MONALEESA-3 reports the longest mOS thus far (67.6 months) for 1L patients in a phase III ABC trial. These results in a 1L population show that the OS benefit of ribociclib was maintained through extended follow-up, further supporting its use in HR+/HER2- ABC.

Topics: Breast Neoplasms; Female; Fulvestrant; Humans; Postmenopause; Proportional Hazards Models

This phase II study evaluated the impact of adding ribociclib to maintenance endocrine therapy (ET) treatment of physicians' choice following the first palliative chemotherapy in pre- and post-menopausal women with hormone receptor positive (HR+)/human epidermal growth factor 2 negative (HER2-) metastatic breast cancer (mBC).. The initial randomized study design was later amended into a single-arm study, and all subsequent patients received ribociclib and ET. The primary end point was locally assessed progression-free survival (PFS). Secondary end points included overall survival (OS), clinical benefit rate (CBR), safety, compliance, and quality of life (QoL).. A total of 43 patients received ribociclib + ET and 10 patients received ET only. Median PFS was 12.4 months [95% CI 8.7-24.4] for patients who received ribociclib + ET and 4.75 months [95% CI 1.0-10.3] for those who received ET only. Median OS was not reached for patients who received ribociclib + ET, and 28 (65.1%) patients experienced clinical benefit [95% CI 49.1-79.0]. For patients who received ribociclib + ET, grade 3-4 hematological adverse events (AEs) occurred in 25 (58.1%) patients, and grade 3-4 non-hematological AEs occurred in 17 (39.5%) patients. During the study, 15 patients died - 14 of whom due to tumor-related reasons, and one patient due to pneumonia, which was not treatment-related.. The results of the AMICA study show a promising efficacy and safety of maintenance treatment with ribociclib added to ET after at least stable disease following the first metastatic chemotherapy in patients with HR+/HER2-mBC.. Anti-hormonal Therapy With Ribociclib in HR-positive/HER2- Negative Metastatic Breast Cancer (AMICA), NCT03555877, https://clinicaltrials.gov/ct2/show/NCT03555877.

Topics: Aminopyridines; Antineoplastic Combined Chemotherapy Protocols; Breast Neoplasms; Cyclin-Dependent Kinase 4; Cyclin-Dependent Kinase 6; Female; Humans; Quality of Life; Receptor, ErbB-2

Ribociclib plus endocrine therapy (ET) demonstrated a statistically significant progression-free survival and overall survival (OS) benefit in the phase III MONALEESA-7 trial of pre-/perimenopausal patients with hormone receptor (HR)-positive (HR+), HER2-negative (HER2-) advanced breast cancer (ABC). The median OS was not reached in the ribociclib arm in the protocol-specified final analysis; we hence performed an exploratory OS and additional outcomes analysis with an extended follow-up (median, 53.5 months).. Patients were randomized to receive ET [goserelin plus nonsteroidal aromatase inhibitor (NSAI) or tamoxifen] with ribociclib or placebo. OS was evaluated with a stratified Cox proportional hazard model and summarized with Kaplan-Meier methods.. The intent-to-treat population included 672 patients. Median OS was 58.7 months with ribociclib versus 48.0 months with placebo [hazard ratio = 0.76; 95% confidence interval (CI), 0.61-0.96]. Kaplan-Meier estimated OS at 48 months was 60% and 50% with ribociclib and placebo, respectively. Subgroup analyses were generally consistent with the OS benefit, including patients who received NSAI and patients aged less than 40 years. Subsequent antineoplastic therapies following discontinuation were balanced between the ribociclib (77%) and placebo (78%) groups. Use of cyclin-dependent kinase 4/6 inhibitors after discontinuation was higher with placebo (26%) versus ribociclib (13%). Time to first chemotherapy was significantly delayed with ribociclib versus placebo. No drug-drug interactions were observed between ribociclib and either NSAI.. Ribociclib plus ET continued to show significantly longer OS than ET alone in pre-/perimenopausal patients, including patients aged less than 40 years, with HR+/HER2- ABC with 53.5 months of median follow-up (ClinicalTrials.gov, NCT02278120).

Topics: Aminopyridines; Antineoplastic Combined Chemotherapy Protocols; Aromatase Inhibitors; Breast Neoplasms; Female; Humans; Perimenopause; Purines; Receptor, ErbB-2; Receptors, Estrogen

MONALEESA-3 demonstrated an overall survival (OS) benefit for ribociclib plus fulvestrant (R+F) in postmenopausal women with hormone receptor (HR) positive, HER2 negative advanced breast cancer (ABC). This study estimated quality-adjusted (QA) survival outcomes for patients receiving R+F vs. placebo (P)+F in MONALEESA-3.. Kaplan-Meier OS was partitioned into health states: (1) toxicity (TOX)=time spent with grade 3 -4 adverse events before progression (DP); (2) progression (PROG)=time between DP and death; and (3) time without symptoms or toxicity (TWiST)=time not in TOX or PROG. QA time was calculated by combining estimated mean time in each health state with treatment-group specific health-state utility values estimated using EQ-5D-5L questionnaire. Outcomes included QA progression-free survival (QAPFS), QAOS, and QA TWiST (Q-TWiST). Q-TWiST was calculated with health-state utility values for TOX and PROG defined relative to TWiST.. Mean PFS and OS were significantly greater with R+F vs. P+F (difference 0.56 and 0.19 years). Mean time in TOX and TWiST were greater with R+F; mean time in PROG was greater with P+F. QAPFS was 0.45 years (95% CI 0.27 -0.63) greater with R+F than P+F (P <.001). QAOS was numerically greater with R+F vs. P+F (0.16 years, 95% CI 0.07 -0.45, P = .0569). Q-TWiST was 0.23 years greater with R+F (95% CI 0.07 -0.45, P = .0069). In a sensitivity analysis using an estimate of disutility for PROG, the difference in QAOS was 0.23 years (95% CI 0.08 -0.41, P = .0022).. R+F in postmenopausal women with HR+/HER2- ABC improves QAPFS, resulting in clinically important improvements in Q-TWiST and may improve QAOS.

Topics: Aminopyridines; Antineoplastic Combined Chemotherapy Protocols; Breast Neoplasms; Female; Fulvestrant; Humans; Postmenopause; Purines

The phase IIIb CompLEEment-1 study evaluated ribociclib plus letrozole in patients with hormone receptor-positive (HR+), human epidermal growth factor receptor 2-negative (HER2-) advanced breast cancer (ABC). Outcomes were investigated in the following subgroups: central nervous system (CNS) metastases, prior chemotherapy for advanced disease, Eastern Cooperative Oncology Group (ECOG) performance status (PS) 2, and visceral metastases plus prior chemotherapy for advanced disease or ECOG PS 2.. Patients with HR+, HER2- ABC without prior hormonal treatment for advanced disease received oral ribociclib (600 mg once daily, 3 weeks on/1 week off) plus letrozole (2.5 mg once daily, continuous). Primary endpoint was safety/tolerability, assessed via occurrence of adverse events (AEs); key secondary endpoints included time to progression (TTP), overall response rate, and clinical benefit rate.. 51 patients had CNS metastases, 194 received prior chemotherapy for advanced disease, 112 had ECOG PS 2, 146 had visceral metastases plus prior chemotherapy, and 77 had visceral metastases plus ECOG PS 2. Safety results were consistent with those in the overall CompLEEment-1 population; no new safety concerns were identified. The AE profile was manageable with low rates of discontinuations due to AEs. TTP in patients with CNS metastases was consistent with the overall study population and shorter for other patient subgroups. Each patient subgroup achieved meaningful clinical benefit from treatment, consistent with the overall population.. These findings confirm the clinical benefit of ribociclib plus endocrine therapy in high-risk patient subgroups of clinical interest commonly underrepresented in clinical trials.

Topics: Aminopyridines; Antineoplastic Combined Chemotherapy Protocols; Breast Neoplasms; Female; Hormones; Humans; Letrozole; Purines; Receptor, ErbB-2; Receptors, Estrogen; Receptors, Progesterone

In a previous analysis of this phase 3 trial, first-line ribociclib plus letrozole resulted in significantly longer progression-free survival than letrozole alone among postmenopausal patients with hormone receptor (HR)-positive, human epidermal growth factor receptor 2 (HER2)-negative advanced breast cancer. Whether overall survival would also be longer with ribociclib was not known.. Here we report the results of the protocol-specified final analysis of overall survival, a key secondary end point. Patients were randomly assigned in a 1:1 ratio to receive either ribociclib or placebo in combination with letrozole. Overall survival was assessed with the use of a stratified log-rank test and summarized with the use of Kaplan-Meier methods after 400 deaths had occurred. A hierarchical testing strategy was used for the analysis of progression-free survival and overall survival to ensure the validity of the findings.. After a median follow-up of 6.6 years, 181 deaths had occurred among 334 patients (54.2%) in the ribociclib group and 219 among 334 (65.6%) in the placebo group. Ribociclib plus letrozole showed a significant overall survival benefit as compared with placebo plus letrozole. Median overall survival was 63.9 months (95% confidence interval [CI], 52.4 to 71.0) with ribociclib plus letrozole and 51.4 months (95% CI, 47.2 to 59.7) with placebo plus letrozole (hazard ratio for death, 0.76; 95% CI, 0.63 to 0.93; two-sided P = 0.008). No new safety signals were observed.. First-line therapy with ribociclib plus letrozole showed a significant overall survival benefit as compared with placebo plus letrozole in patients with HR-positive, HER2-negative advanced breast cancer. Median overall survival was more than 12 months longer with ribociclib than with placebo. (Funded by Novartis; MONALEESA-2 ClinicalTrials.gov number, NCT01958021.).

Topics: Aged; Aminopyridines; Antineoplastic Combined Chemotherapy Protocols; Breast Neoplasms; Female; Humans; Intention to Treat Analysis; Letrozole; Middle Aged; Neoplasm Grading; Neutropenia; Purines; Receptor, ErbB-2; Receptors, Estrogen; Survival Analysis

The CDK4/6 inhibitor, ribociclib in combination with endocrine therapy significantly improved progression-free survival in the first line setting in post-menopausal patients with HR+/HER2- advanced breast cancer (ABC) in a pivotal phase 3, placebo-controlled trial (MONALEESA-2) and demonstrated superior overall survival in premenopausal patients with HR+/HER2- ABC (MONALEESA-7). The multinational, phase 3b, CompLEEment-1 trial, which assessed the safety and efficacy of ribociclib plus letrozole in a broader population of patients who have not received prior endocrine therapy for advanced disease, is the largest phase 3 clinical trial to date to evaluate the safety and efficacy of a CDK4/6 inhibitor. We report a subanalysis of data from patients (N = 339) enrolled in the central and south European countries of the SERCE (Southern Europe, RUC, Central Europe) cluster of CompLEEment-1.. Men and women of any menopausal status with HR+/HER2- ABC received once-daily oral ribociclib 600 mg (3-weeks on/1-week-off), plus letrozole 2.5 mg continuously. Men/premenopausal women also received a GnRH-agonist. The primary outcome was the number of patients with adverse events (AEs) over a timeframe of approximately 36 months. Time-to-progression, overall response rate, and clinical benefit rate were also measured.. Safety results in the SERCE subgroup were consistent with those in the pivotal clinical trials of ribociclib in combination with endocrine therapy. Treatment-related AEs leading to dose adjustments/interruption occurred in 63.1% of patients but led to treatment discontinuation in only 10.6%. The most common treatment-related AEs of grade ≥ 3 were neutropenia and transaminase elevations. There were no fatal treatment-related events.. These findings from the SERCE subgroup support the safety and manageable tolerability of ribociclib in a broad range of patients with HR+/HER2- ABC more representative of patients in real-world clinical practice.

Topics: Aminopyridines; Antineoplastic Combined Chemotherapy Protocols; Breast Neoplasms; Female; Humans; Letrozole; Male; Purines; Receptor, ErbB-2; Receptors, Estrogen; Receptors, Progesterone

In the phase II CORALLEEN trial, patients with PAM50 luminal B early breast cancer (EBC) were randomised to neoadjuvant ribociclib plus letrozole (R + L) or chemotherapy based on anthracyclines and taxanes. Results from the primary efficacy analysis showed a similar proportion of patients with response at surgery in both groups. How health-related quality of life (HRQoL) outcomes with R + L compare with chemotherapy in EBC setting is still unknown. Here, we report the results of the HRQoL analysis from the CORALLEEN study.. A total of 106 women were randomised 1:1 to receive neoadjuvant R + L (n = 52) or chemotherapy (n = 54). Patient-reported outcomes were assessed using two questionnaires: EORTC QLQ-C30 and EORTC QLQ-BR23. Change from baseline in the global health status, functional, and symptom scales was analysed using linear mixed-effect models, and between-treatment differences were estimated along with 95% confidence interval (95% CI).. At baseline, the overall questionnaire available rate was 94.3%, and patient-reported outcomes were similar between treatment groups. At the end of the study treatment (24 weeks), patients receiving R + L showed better global health status scores with a between-treatment difference of 17.7 points (95% CI 9.2-26.2; p-value <0.001). The R + L group also presented numerically better outcomes in all functional and symptom scales. The larger between-treatment differences in symptom severity were found in fatigue (-28.9; 95% CI -38.5 to -19.3), appetite loss (-23; 95% CI -34.9 to -11.2) and systematic therapy side-effects (-11.4; 95% CI -18.3 to -4.6).. Neoadjuvant R + L was associated with better HRQoL outcomes compared with chemotherapy in patients with luminal B EBC.. ClinicalTrials.gov Identifier: NCT03248427.

Topics: Aminopyridines; Anthracyclines; Antineoplastic Combined Chemotherapy Protocols; Aromatase Inhibitors; Breast Neoplasms; Female; Humans; Letrozole; Purines; Quality of Life; Taxoids

Ribociclib plus letrozole demonstrated manageable safety and efficacy profiles in hormone receptor-positive (HR+), human epidermal growth factor receptor-2-negative (HER2-) advanced breast cancer (ABC) in the Phase 3b CompLEEment-1 trial.. To evaluate the safety and efficacy of ribociclib plus letrozole in the Italian subpopulation with HR+, HER2- ABC from the CompLEEment-1 trial.. Patients with HR+, HER2- ABC received ribociclib (600 mg/day, 3 weeks on/1 week off) plus letrozole (2.5 mg/day) while men and premenopausal women additionally received goserelin. Patients were allowed with ≤ 1 line of prior chemotherapy and an Eastern Cooperative Oncology Group performance status of ≤ 2. The primary outcome included safety and tolerability.. Of the 554 Italian patients, 246 (44.4 %) patients completed treatment. The reasons for treatment discontinuation included progressive disease (PD; 36.6 %), adverse events (AEs; 11.9 %), and death (1.6 %). All-grade AEs and grade ≥ 3 AEs occurred in 98.9 % and 77.8 % patients, respectively. The most common treatment-related AEs were neutropenia (73.6 %), followed by leukopenia (32.1 %), and nausea (25.3 %). The overall response rate was 28.2 % (95 % confidence interval [CI], 24.4-32.1); clinical benefit rate was 71.7 % (95 % CI, 67.7-75.4); and median time to progression was 26.7 months (95 % CI, 24.8-non-estimable). Health-related quality of life scores were maintained during treatment.. The safety and efficacy profiles of ribociclib plus letrozole in the Italian subpopulation was found to be consistent with the CompLEEment-1 global population result, MONALEESA-2, and MONALEESA-7 outcomes, which reaffirm ribociclib plus letrozole as the frontline treatment option in patients with HR+, HER2- ABC.. NCT02941926 (30 November 2016).

Topics: Antineoplastic Combined Chemotherapy Protocols; Breast Neoplasms; Female; Humans; Letrozole; Quality of Life; Receptor, ErbB-2; Receptors, Estrogen; Receptors, Progesterone

Breast cancer is the most common malignancy and the second leading cause of cancer-related mortality in Spanish women. Ribociclib in combination with endocrine therapy (ET) has shown superiority in prolonging survival in patients with hormone receptor-positive (HR+), human epidermal growth factor receptor 2-negative (HER2-) advanced breast cancer (ABC) vs. ET alone.. CompLEEment-1 is a single-arm, open-label phase 3b trial evaluating ribociclib plus letrozole in a broad population of patients with HR+, HER2- ABC. The primary endpoints were safety and tolerability. Here we report data for Spanish patients enrolled in CompLEEment-1.. A total of 526 patients were evaluated (median follow-up: 26.97 months). Baseline characteristics showed a diverse population with a median age of 54 years. At study entry, 56.5% of patients had visceral metastases and 8.7% had received prior chemotherapy for advanced disease. Rates of all-grade and Grade ≥3 adverse events (AEs) were 99.0% and 76.2%, respectively; 21.3% of patients experienced a serious AE, and 15.8% of AEs led to treatment discontinuation. AEs of special interest of neutropenia, increased alanine aminotransferase, increased aspartate aminotransferase and QTcF prolongation occurred in 77.8%, 14.8%, 11.4% and 4.0% of patients, respectively. Patients aged >70 years experienced increased rates of all-grade and Grade ≥3 neutropenia and anemia. Efficacy results were consistent with the global study.. Results from Spanish patients enrolled in CompLEEment-1 are consistent with global data showing efficacy and a manageable safety profile for ribociclib plus letrozole treatment in patients with HR+, HER2- ABC, including populations of interest (NCT02941926).. ClinicalTrials.gov NCT02941926.

Topics: Aminopyridines; Antineoplastic Combined Chemotherapy Protocols; Aromatase Inhibitors; Breast Neoplasms; Female; Humans; Letrozole; Middle Aged; Neutropenia; Protein Kinase Inhibitors; Receptor, ErbB-2

This analysis evaluated the genomic landscape of premenopausal patients with hormone receptor-positive and human epidermal growth factor receptor 2-negative advanced breast cancer and the association of genetic alterations with response to ribociclib in the phase III MONALEESA-7 trial.. Premenopausal patients were randomly assigned 1:1 to receive endocrine therapy plus ribociclib or placebo. Plasma collected at baseline was sequenced using targeted next-generation sequencing for approximately 600 relevant cancer genes. The association of circulating tumor DNA alterations with progression-free survival (PFS) was evaluated to identify biomarkers of response and resistance to ribociclib.. Baseline circulating tumor DNA was sequenced in 565 patients; 489 had evidence of ≥ 1 alteration. The most frequent alterations included. In this study-to our knowledge, the first large study of premenopausal patients with hormone receptor-positive and human epidermal growth factor receptor 2-negative advanced breast cancer-multiple genomic alterations were associated with poor outcome. A PFS benefit of ribociclib was observed regardless of gene alteration status, although in this exploratory analysis, a magnitude of benefits varied by alteration.

Topics: Adolescent; Adult; Aminopyridines; Antineoplastic Agents, Hormonal; Antineoplastic Combined Chemotherapy Protocols; Biomarkers, Tumor; Breast Neoplasms; Circulating Tumor DNA; Double-Blind Method; Drug Resistance, Neoplasm; Female; Genomics; Humans; Middle Aged; Premenopause; Progression-Free Survival; Proportional Hazards Models; Purines; Receptor, ErbB-2; Transcription Factors; Young Adult

Ribociclib is an orally bioavailable, highly selective small-molecule inhibitor of cyclin-dependent kinases 4 and 6. It is currently approved for the treatment of hormone receptor-positive, human epidermal growth factor receptor 2-negative breast cancer with a starting dose of 600 mg. Both in vitro and in vivo studies indicate that ribociclib is primarily metabolized in the liver via cytochrome P450 3A4. A phase 1, open-label, multicenter, parallel cohort, single-oral-dose study was conducted to characterize the pharmacokinetics of ribociclib in subjects with varying degrees of hepatic impairment as measured by the Child-Pugh classification. Subjects were divided into 4 cohorts determined by their degree of hepatic impairment: normal, mild, moderate, or severe. Thirty subjects were enrolled and received a single 400 mg dose of ribociclib. Ribociclib exposure was similar in subjects with mild hepatic impairment compared with subjects with normal hepatic function, but was increased by approximately 30% in subjects with moderate and severe hepatic impairment. At a dose of 400 mg, ribociclib was generally well tolerated in all subjects regardless of the level of hepatic impairment. These results indicate that no dose adjustment (recommended dose of ribociclib is 600 mg daily, 3 weeks on and 1 week off) is necessary for patients with mild hepatic impairment but that a reduced dose of 400 mg daily, 3 weeks on and 1 week off in patients with moderate or severe hepatic impairment is recommended.

Topics: Aminopyridines; Antineoplastic Agents; Area Under Curve; Breast Neoplasms; Female; Half-Life; Humans; Liver Diseases; Male; Metabolic Clearance Rate; Middle Aged; Patient Acuity; Purines

We conducted a cost-effectiveness analysis incorporating recent phase III clinical trial (MONALEESA-7) data to evaluate the cost-effectiveness of ribociclib (RIB) as a first-line treatment for premenopausal women with hormone receptor (HR)-positive and human epidermal growth factor receptor 2 (HER2)-negative advanced breast cancer (ABC) from the United States healthcare payer perspective. In addition, because RIB has not been marketed in China, we identified the range of drug costs for which RIB could be considered cost effective from a Chinese healthcare system perspective.. A Markov model was developed to evaluate the cost-effectiveness of adding RIB to endocrine therapy over a lifetime. The clinical outcomes and utility data were obtained from published literature. Costs data were obtained from United States and Chinese official websites, and we determined the potential price for RIB in China based on its price in the United States. The main outcomes of this study were the incremental cost-effectiveness ratio (ICER) and quality-adjusted life-years (QALYs).. The model projected that mean outcome was better with RIB and endocrine combined (3.83366 QALYs) than with endocrine therapy alone (2.71203 QALYs). In the United States, RIB and endocrine therapy cost an additional $604,960.06, resulting in an ICER of $539,357.95/QALY compared with endocrine monotherapy. Subgroup analyses indicated that, in China, the projected mean outcomes were better for RIB and endocrine therapy (6.37 QALYs) than for endocrine monotherapy (2.71 QALYs). The corresponding incremental costs were $224,731.88943. Thus, the ICER comparing RIB and endocrine therapy with endocrine therapy alone represented a $61,454.96/QALY gain.. Additional use of RIB is estimated to not be cost effective as a first-line treatment for premenopausal women with HR-positive, HER2-negative ABC in the United States. A value-based price for the cost of RIB is less than $31.74/200 mg for China.

Topics: Aminopyridines; Antineoplastic Agents, Hormonal; Breast Neoplasms; China; Cost-Benefit Analysis; Drug Costs; Drug Therapy, Combination; Estrogen Antagonists; Estrogen Receptor Modulators; Female; Humans; Markov Chains; Premenopause; Purines; Quality-Adjusted Life Years; Receptor, ErbB-2; United States

The population pharmacokinetics (popPK) of ribociclib and population pharmacokinetic/pharmacodynamic (PK/PD) relationship between ribociclib and absolute neutrophil count (ANC) were characterized in patients with cancer. PopPK and ANC PK/PD modeling were both conducted in 2 rounds per data availability. Initial models were developed based on data sets from early-phase trials and qualified using external data from the phase III MONALEESA-2 trial. The second round of analyses was performed using updated data sets that included 2 more phase III trials (MONALEESA-3 and -7). The popPK and ANC PK/PD models adequately described the data and demonstrated reasonable predictive ability. Covariate analysis showed that ribociclib PK were not affected by age, sex, race, baseline Eastern Cooperative Oncology Group (ECOG) status (grade 1), mild/moderate renal impairment, mild hepatic impairment, or concomitant use of combination partners, including aromatase inhibitors (letrozole, anastrozole) or fulvestrant, proton-pump inhibitors, or weak cytochrome P450 3A4/5 inhibitors. Body weight had no impact on ribociclib clearance to warrant dose adjustment. The ANC PK/PD relationship was not affected by age, weight, sex, race, baseline ECOG status (grade 1), or concomitant use of letrozole, anastrozole, or fulvestrant. The PK/PD analysis confirmed reversibility of ribociclib's effect on ANC; it also suggested that lowering the dose of ribociclib would mitigate ANC decrease and neutropenia risk. The popPK and ANC PK/PD analyses support the use of ribociclib in combination with an aromatase inhibitor or fulvestrant in patients with hormone receptor-positive, human epidermal growth factor receptor-2-negative advanced or metastatic breast cancer without dose adjustment in subpopulations, and the use of dose interruption/reduction to mitigate potential treatment-emergent neutropenia.

Topics: Adult; Age Factors; Aged; Aminopyridines; Antineoplastic Agents; Area Under Curve; Body Weight; Breast Neoplasms; Drug Interactions; Female; Humans; Kidney Function Tests; Liver Function Tests; Male; Metabolic Clearance Rate; Metabolic Networks and Pathways; Middle Aged; Models, Biological; Neoplasm Metastasis; Neutrophils; Purines; Racial Groups; Receptor, ErbB-2; Receptors, Progesterone; Sex Factors

Ribociclib plus fulvestrant demonstrated significant progression-free survival (PFS) and overall survival (OS) benefits in patients with hormone receptor-positive, human epidermal growth factor receptor 2-negative (HR+/HER2-) advanced breast cancer (ABC). Here we present a new landmark in survival follow-up for a phase III cyclin-dependent kinases 4 and 6 inhibitor clinical trial in patients with ABC (median, 56.3 months).. This phase III, randomized, double-blind, placebo-controlled trial was conducted at 174 sites (30 countries). Patients were men and postmenopausal women (age ≥18 years) with histologically/cytologically confirmed HR+/HER2- ABC. Patients could have received ≤1 line of endocrine therapy (ET) but no chemotherapy for ABC. Patients, assigned 2:1, were stratified by the presence/absence of liver/lung metastases and previous ET. Patients received intramuscular fulvestrant (500 mg, day 1 of each 28-day cycle plus day 15 of cycle 1) with oral ribociclib (600 mg/day, 3 weeks on, 1 week off) or placebo. Efficacy analyses were by intention to treat. Safety was assessed in patients receiving ≥1 dose study treatment. OS was a secondary endpoint. MONALEESA-3 is registered with ClinicalTrials.gov (NCT02422615; no longer enrolling).. Between 18 June 2015 and 10 June 2016, 726 patients were randomly assigned (484, ribociclib; 242, placebo). At data cut-off (30 October 2020), median OS (mOS) was 53.7 months (ribociclib) versus 41.5 months (placebo) [hazard ratio (HR), 0.73; 95% confidence interval (CI) 0.59-0.90]. Subgroup analyses were consistent with overall population. In the first-line setting, most patients in the ribociclib arm (∼60%) lived longer than median follow-up; mOS was 51.8 months in the placebo arm (HR, 0.64; 95% CI 0.46-0.88). In the second-line setting, mOS was 39.7 months (ribociclib) versus 33.7 months (placebo) (HR, 0.78; 95% CI 0.59-1.04). No apparent drug-drug interaction between ribociclib and fulvestrant or new safety signals were observed.. This analysis reported extended OS follow-up in MONALEESA-3. mOS was ∼12 months longer in patients with HR+/HER2- ABC treated with ribociclib plus fulvestrant compared with fulvestrant monotherapy.

Topics: Adolescent; Aminopyridines; Antineoplastic Combined Chemotherapy Protocols; Breast Neoplasms; Double-Blind Method; Female; Fulvestrant; Humans; Postmenopause; Purines; Receptor, ErbB-2; Receptors, Estrogen; Receptors, Progesterone

Topics: Aminopyridines; Antineoplastic Combined Chemotherapy Protocols; Breast Neoplasms; Female; Humans; Postmenopause; Purines; Receptor, ErbB-2; Receptors, Progesterone

This pooled analysis of MONALEESA trials evaluated the safety of ribociclib plus endocrine therapy (RIB + ET) with a focus on dose reductions in first-line patients.. In the dose reduction analysis, data were pooled from MONALEESA-2 (all patients), MONALEESA-3 (patients receiving treatment as first-line ET) and MONALEESA-7 (patients receiving combination therapy with an NSAI as initial ET). Efficacy was analysed by ribociclib relative dose intensity (DI). Safety was analysed in all patients in the trials (except those receiving tamoxifen in MONALEESA-7) and those with/without ≥1 ribociclib dose reduction.. Of 818 women who received first-line RIB + ET, 41.8% required ≥1 dose reduction due to AEs (most commonly, neutropenia). Median RIB relative DI in patients without and with dose reductions was 99.3% and 65.6% in MONALEESA-2, 98.4% and 67.8% in MONALEESA-3 and 98·0% and 66·3% in MONALEESA-7. Median PFS was 24.8, 24.9 and 29.6 months for patients who received ≤71% (30th percentile), 72-96% (60th percentile) and 97-100% (90th percentile) RIB relative DI, respectively. No new safety signals emerged in the pooled safety analysis.. This analysis provides reassuring data showing that the clinical benefit of RIB is preserved when dose modifications are undertaken to manage AEs.. MONALEESA-2 (NCT01958021) first posted October 8, 2013; MONALEESA-3 (NCT02422615) first posted April 21, 2015; MONALEESA-7 (NCT02278120) first posted October 29, 2014.

Topics: Adult; Aged; Aged, 80 and over; Aminopyridines; Antineoplastic Agents, Hormonal; Antineoplastic Combined Chemotherapy Protocols; Breast Neoplasms; Double-Blind Method; Drug Tapering; Female; Humans; Middle Aged; Purines; Receptor, ErbB-2; Receptors, Estrogen; Receptors, Progesterone; Treatment Outcome; Young Adult

Chemotherapy efficacy in early-stage hormone receptor-positive (HR+) breast cancer (BC) according to menopausal status needs a biological explanation.. We compared early-stage HR+ BC biological features before and after (neo)adjuvant chemotherapy or endocrine therapy (ET), and assessed oestrogen receptor (ER) pathway activity in both pre- and post-menopausal patients. The nCounter platform was used to detect gene expression levels.. In 106 post-menopausal patients with HR+/HER2-negative BC randomized to neoadjuvant chemotherapy or ET (letrozole+ribociclib), a total of 19 oestrogen-regulated genes, including progesterone receptor (PGR), were found downregulated in the ET-based arm-only. We confirmed this finding in an independent dataset of 20 letrozole-treated post-menopausal patients and found, conversely, an up-regulation of the same signature in HR+/HER2-negative MCF7 cell line treated with estradiol. PGR was found down-regulated by 2 weeks of ET+anti-HER2 therapy in pre-/post-menopausal patients with HR+/HER2-positive (HER2+) BC, while anti-HER2 therapy alone increased PGR expression in HR-negative/HER2+ BC. In 88 pre- and post-menopausal patients with newly diagnosed HR+/HER2-negative BC treated with chemotherapy, the 19 oestrogen-regulated genes were found significantly downregulated only in pre-menopausal patients. In progesterone receptor (PR)+/HER2-negative BC treated with neoadjuvant chemotherapy (n=40), tumours became PR-negative in 69.2% of pre-menopausal patients and 14.8% of post-menopausal patients (p=0.001). Finally, a mean decrease in PGR levels was only observed in pre-menopausal patients undergoing anti-HER2-based multi-agent chemotherapy.. Chemotherapy reduces the expression of ER-regulated genes in pre-menopausal women suffering from hormone-dependent BC by supressing ovarian function. Further studies should test the value of chemotherapy in this patient population when ovarian function is suppressed by other methods.. Instituto de Salud Carlos III, Breast Cancer Now, the Breast Cancer Research Foundation, the American Association for Cancer Research, Fundació La Marató TV3, the European Union's Horizon 2020 Research and Innovation Programme, Pas a Pas, Save the Mama, Fundación Científica Asociación Española Contra el Cáncer, PhD4MDgrant of "Departament de Salut", exp SLT008/18/00122, Fundación SEOM and ESMO. Any views, opinions, findings, conclusions, or recommendations expressed in this material are those solely of the author(s).

Topics: Adult; Aged; Aminopyridines; Antineoplastic Agents; Breast Neoplasms; Female; Humans; Letrozole; MCF-7 Cells; Menopause; Middle Aged; Neoadjuvant Therapy; Purines; Receptor, ErbB-2; Receptors, Estrogen; Receptors, Progesterone; Transcriptome

CompLEEment-1 is a phase 3b trial in an expanded patient population with hormone receptor-positive (HR +), human epidermal growth factor receptor-2-negative (HER2-) advanced breast cancer (ABC), the largest current trial of cyclin-dependent kinase 4 and 6 inhibitors in ABC.. Patients treated with ≤ 1 line of prior chemotherapy and no prior endocrine therapy for ABC received ribociclib 600 mg/day (3-weeks-on/1-week-off) plus letrozole 2.5 mg/day and additionally monthly goserelin/leuprolide in men and pre-/perimenopausal women. Eligibility criteria allowed inclusion of patients with stable CNS metastases and an Eastern Cooperative Oncology Group performance status of 2. Primary objectives were safety and tolerability, and secondary objectives were efficacy and quality of life (QoL).. Overall, 3,246 patients were evaluated (median follow-up 25.4 months). Rates of all-grade and grade ≥ 3 treatment-related adverse events (AEs) were 95.2% and 67.5%, respectively. Treatment-related discontinuations due to all grade and grade ≥ 3 AEs occurred in 12.9% and 7.3% of patients, respectively. Rates of all-grade AEs of special interest (AESI) were as follows: neutropenia (74.5%), increased alanine aminotransferase (16.2%), increased aspartate aminotransferase (14.1%), and QTcF prolongation (6.7%); corresponding values for grade ≥ 3 AESI were 57.2%, 7.7%, 5.7%, and 1.0%, respectively. Median time to progression was 27.1 months (95% confidence interval, 25.7 to not reached). Patient QoL was maintained during treatment.. Safety and efficacy data in this expanded population were consistent with the MONALEESA-2 and MONALEESA-7 trials and support the use of ribociclib plus letrozole in the first-line setting for patients with HR + , HER2- ABC.. linicalTrials.gov NCT02941926.

Topics: Aminopyridines; Antineoplastic Combined Chemotherapy Protocols; Breast Neoplasms; Female; Humans; Letrozole; Purines; Quality of Life; Receptor, ErbB-2; Receptors, Estrogen; Receptors, Progesterone

In an earlier analysis of this phase 3 trial, ribociclib plus fulvestrant showed a greater benefit with regard to progression-free survival than fulvestrant alone in postmenopausal patients with hormone-receptor-positive, human epidermal growth factor receptor 2 (HER2)-negative advanced breast cancer. Here we report the results of a protocol-specified second interim analysis of overall survival.. Patients were randomly assigned in a 2:1 ratio to receive either ribociclib or placebo in addition to fulvestrant as first-line or second-line treatment. Survival was evaluated by means of a stratified log-rank test and summarized with the use of Kaplan-Meier methods.. This analysis was based on 275 deaths: 167 among 484 patients (34.5%) receiving ribociclib and 108 among 242 (44.6%) receiving placebo. Ribociclib plus fulvestrant showed a significant overall survival benefit over placebo plus fulvestrant. The estimated overall survival at 42 months was 57.8% (95% confidence interval [CI], 52.0 to 63.2) in the ribociclib group and 45.9% (95% CI, 36.9 to 54.5) in the placebo group, for a 28% difference in the relative risk of death (hazard ratio, 0.72; 95% CI, 0.57 to 0.92; P = 0.00455). The benefit was consistent across most subgroups. In a descriptive update, median progression-free survival among patients receiving first-line treatment was 33.6 months (95% CI, 27.1 to 41.3) in the ribociclib group and 19.2 months (95% CI, 14.9 to 23.6) in the placebo group. No new safety signals were observed.. Ribociclib plus fulvestrant showed a significant overall survival benefit over placebo plus fulvestrant in patients with hormone-receptor-positive, HER2-negative advanced breast cancer. (Funded by Novartis; MONALEESA-3 ClinicalTrials.gov number, NCT02422615.).

Topics: Aged; Aminopyridines; Antineoplastic Combined Chemotherapy Protocols; Breast Neoplasms; Drug Administration Schedule; Female; Fulvestrant; Humans; Kaplan-Meier Estimate; Middle Aged; Postmenopause; Progression-Free Survival; Purines; Receptor, ErbB-2; Receptors, Estrogen; Receptors, Progesterone

Breast cancer is the most common female tumour type and accounts for the leading cancer mortality in women worldwide. Up to 75% of breast cancers express the oestrogen receptor or progesterone receptor (hormone-receptor-positive). Aromatase inhibitors were the preferred first-line treatment option. New and acquired resistance to hormonal blockade has led to the development of targeted treatments. Cyclin-dependent kinases (CDKs) are a large family of serine-threonine kinases that play an important role in regulating cell cycle progression: palbociclib, ribociclib, and abemaciclib. We conducted a study to evaluate the efficacy of CDK inhibitors (CDKi) plus aromatase inhibitor in hormone-receptor-positive/HER2-negative ABC patients with visceral disease, postponing the use of chemotherapeutic agents and strengthening the power of endocrine agents. We enrolled 22 patients treated with CDKi (palbocilib) plus aromatase inhibitor (group A) and 38 patients treated with chemotherapy (group B). Our small study confirms the effectiveness of treatment with CDKi plus aromatase inhibitor, even in patients with visceral metastases, when compared with chemotherapy.

Topics: Adult; Aged; Aged, 80 and over; Aminopyridines; Antineoplastic Combined Chemotherapy Protocols; Breast Neoplasms; Female; Follow-Up Studies; Humans; Letrozole; Middle Aged; Neoplasm Metastasis; Piperazines; Prognosis; Purines; Pyridines; Receptor, ErbB-2; Retrospective Studies; Survival Rate; Viscera

Ribociclib, a selective and potent cyclin-dependent kinase 4/6 inhibitor, has demonstrated safety and efficacy in combination with endocrine therapy in hormone receptor-positive, human epidermal growth factor receptor-2-negative advanced breast cancer. In 2 open-label crossover studies in healthy participants, the absolute bioavailability of a single oral dose of a ribociclib 600-mg tablet (n = 16) was compared with a single intravenous ribociclib infusion of 150 mg (n = 16), and the bioequivalence of a ribociclib 600-mg tablet (n = 31) and a ribociclib 600-mg capsule (n = 31) was evaluated. The pharmacokinetics of ribociclib and its major metabolite, LEQ803, were assessed in both studies. The oral bioavailability of the 600-mg ribociclib tablet was 65.8% (90% confidence interval [CI], 59.1-73.2%). The geometric mean systemic clearance of ribociclib was moderate (40.2 L/h; 27.4% intersubject variability [CV%]) compared with hepatic blood flow, and the geometric mean volume of distribution was high (979 L; 25.2 CV%). LEQ803-to-ribociclib metabolic ratios were 0.198 for the oral administration and 0.125 for intravenous infusion. Bioequivalence of the tablet and capsule formulations was demonstrated for ribociclib. The geometric mean ratios of maximum concentration and area under the curve from time 0 to last quantifiable concentration and to infinity were 1.01, 1.00, and 0.937, respectively, within the predefined bioequivalence range of 0.80 to 1.25. The median time to reach maximum concentration was 3 hours with both formulations. No serious adverse events were observed in either study.

Topics: Administration, Oral; Adult; Aminopyridines; Biological Availability; Breast Neoplasms; Cross-Over Studies; Cyclin-Dependent Kinase 4; Cyclin-Dependent Kinase 6; Drug Compounding; Female; Healthy Volunteers; Humans; Infusions, Intravenous; Male; Middle Aged; Purines; Receptor, ErbB-2; Safety; Severity of Illness Index; Therapeutic Equivalency

In the MONALEESA-3 Phase III trial of patients with hormone receptor-positive human epidermal growth factor receptor-negative advanced breast cancer, ribociclib plus fulvestrant significantly improved progression-free survival (PFS) and overall survival (OS). Here, we present patient-reported outcomes from the trial, including health-related quality of life (HRQOL).. Patients were randomized (2:1) to receive ribociclib plus fulvestrant or placebo plus fulvestrant. Time to definitive 10% deterioration (TTD) from baseline in HRQOL (global health status [GHS] from the EORTC QLQ-C30 questionnaire) and pain (BPI-SF questionnaire) were assessed using Kaplan-Meier estimates; a stratified Cox regression model was used to estimate the hazard ratio (HR) and 95% CIs.. Deterioration ≥10% in the EORTC-QLQ-C30 GHS was observed in 33% of patients in the ribociclib group vs 34% of patients in the placebo (reference) group (HR for TTD ≥ 10% = 0.81 [95% CI, 0.62-1.1]). Similar findings were noted for TTD ≥5% (HR = 0.79 [95% CI, 0.61-1.0]) and TTD ≥15% (HR = 0.81 [95% CI, 0.60-1.08]). TTD ≥10% in emotional functioning (HR = 0.76 [95% CI, 0.57-1.01]) trended in favor of the ribociclib group, whereas results for fatigue and pain were similar between arms. TTD ≥10% in BPI-SF pain severity index score (HR = 0.77 [95% CI, 0.57-1.05]) and worst pain item score (HR = 0.81 [95% CI, 0.58-1.12]) trended in favor of ribociclib vs placebo.. In addition to significantly prolonging PFS and OS compared with placebo plus fulvestrant, adding ribociclib to fulvestrant maintains HRQOL.

Topics: Adult; Aged; Aged, 80 and over; Aminopyridines; Antineoplastic Combined Chemotherapy Protocols; Breast Neoplasms; Double-Blind Method; Female; Fulvestrant; Health Status; Humans; Kaplan-Meier Estimate; Middle Aged; Patient Reported Outcome Measures; Progression-Free Survival; Proportional Hazards Models; Purines; Quality of Life; Receptor, ErbB-2; Receptors, Estrogen; Receptors, Progesterone

CDK 4/6 inhibitors have given patients with estrogen receptor (ER)-positive/HER2-negative (ER+/HER2ࢤ) advanced metastatic breast cancer important new therapeutic options. Abemaciclib is different to the other two licensed and approved CDK 4/6 inhibitors, palbociclib and ribociclib, both in dosing schedule (continuous vs intermittent) and toxicity profile (less neutropenia, more diarrhea), yet the magnitude of clinical benefit seen in first- and second-line studies is very similar. One of the key issues for clinicians is when to use these therapies. Ultimately, the biggest impact of abemaciclib could be in the adjuvant setting if the current MONARCH-E trial in high-risk node-positive patients is positive. The emerging biomarker work in the early breast cancer setting (i.e., neoMONARCH) may determine which tumors are most sensitive to abemaciclib.

Topics: Aminopyridines; Animals; Antineoplastic Combined Chemotherapy Protocols; Benzimidazoles; Breast Neoplasms; Cyclin-Dependent Kinase 4; Cyclin-Dependent Kinase 6; Drug Evaluation; Female; Follow-Up Studies; Humans; Mice; Molecular Targeted Therapy; Neoplasm Metastasis; Piperazines; Prognosis; Purines; Pyridines; Receptors, Estrogen; Survival Rate; Tumor Cells, Cultured; Xenograft Model Antitumor Assays

An earlier analysis of this phase 3 trial showed that the addition of a cyclin-dependent kinase 4 and 6 (CDK4/6) inhibitor to endocrine therapy provided a greater benefit with regard to progression-free survival than endocrine therapy alone in premenopausal or perimenopausal patients with advanced hormone-receptor-positive, human epidermal growth factor receptor 2 (HER2)-negative breast cancer. Here we report the results of a protocol-specified interim analysis of the key secondary end point of overall survival.. We randomly assigned patients to receive either ribociclib or placebo in addition to endocrine therapy (goserelin and either a nonsteroidal aromatase inhibitor or tamoxifen). Overall survival was evaluated with the use of a stratified log-rank test and summarized with the use of Kaplan-Meier methods.. A total of 672 patients were included in the intention-to-treat population. There were 83 deaths among 335 patients (24.8%) in the ribociclib group and 109 deaths among 337 patients (32.3%) in the placebo group. The addition of ribociclib to endocrine therapy resulted in significantly longer overall survival than endocrine therapy alone. The estimated overall survival at 42 months was 70.2% (95% confidence interval [CI], 63.5 to 76.0) in the ribociclib group and 46.0% (95% CI, 32.0 to 58.9) in the placebo group (hazard ratio for death, 0.71; 95% CI, 0.54 to 0.95; P = 0.00973 by log-rank test). The survival benefit seen in the subgroup of 495 patients who received an aromatase inhibitor was consistent with that in the overall intention-to-treat population (hazard ratio for death, 0.70; 95% CI, 0.50 to 0.98). The percentage of patients who received subsequent antineoplastic therapy was balanced between the groups (68.9% in the ribociclib group and 73.2% in the placebo group). The time from randomization to disease progression during receipt of second-line therapy or to death was also longer in the ribociclib group than in the placebo group (hazard ratio for disease progression or death, 0.69; 95% CI, 0.55 to 0.87).. This trial showed significantly longer overall survival with a CDK4/6 inhibitor plus endocrine therapy than with endocrine therapy alone among patients with advanced hormone-receptor-positive, HER2-negative breast cancer. No new concerns regarding toxic effects emerged with longer follow-up. (Funded by Novartis; MONALEESA-7 ClinicalTrials.gov number, NCT02278120.).

Topics: Adult; Aminopyridines; Antineoplastic Combined Chemotherapy Protocols; Aromatase Inhibitors; Breast Neoplasms; Cyclin-Dependent Kinases; Double-Blind Method; Female; Follow-Up Studies; Humans; Intention to Treat Analysis; Middle Aged; Perimenopause; Premenopause; Protein Kinase Inhibitors; Purines; Receptor, ErbB-2; Receptors, Estrogen; Receptors, Progesterone; Survival Analysis; Tamoxifen

Signaling through the cyclin-dependent kinase 4 and 6 (CDK4/6) pathway can mediate therapeutic resistance in HER2-positive breast cancer. Preclinical studies have demonstrated that CDK4/6 inhibitors can resensitize resistant HER2-positive breast cancer to anti-HER2 therapies.. We conducted a phase 1b/2 study of ribociclib (400 mg per day on a continuous schedule) plus trastuzumab (6 mg/kg every 3 weeks) in patients with advanced HER2-positive breast cancer previously treated with trastuzumab, pertuzumab, and trastuzumab emtansine. There were no restrictions on the number of prior therapy lines. Primary objective was clinical benefit rate at 24 weeks, and secondary objectives included safety, objective response, rate and progression-free survival. The study was enrolled at ClinicalTrials.gov as NCT02657343.. From March 2016 to March 2017, 13 patients were enrolled. One patient was found to have HER2-negative disease and did not receive treatment. Median number of prior lines in the metastatic setting was 5 (range, 0-14); 67% had hormone receptor-positive disease. No dose-limiting toxicities were observed during the safety run-in phase, and ribociclib was thus dosed at 400 mg per day continuously for the expansion cohort. Grade 3 adverse events were observed in 4 patients (33.3%) and included neutropenia (n = 2) as well as fatigue and pain in 1 patient each. No grade 4/5 adverse events or QTc prolongation were observed. One patient (8.3%) experienced stable disease > 24 weeks; no objective responses were observed, and median progression-free survival was 1.33 months (95% confidence interval, 0.92-2.57).. Continuous low-dose ribociclib (400 mg) plus trastuzumab is safe, with no new safety concerns. The limited activity observed in this study suggests that further study of CDK4/6 inhibitor/anti-HER2 combinations should focus on a less pretreated population.

Topics: Adult; Aged; Aminopyridines; Antineoplastic Combined Chemotherapy Protocols; Breast Neoplasms; Cohort Studies; Female; Follow-Up Studies; Humans; Middle Aged; Prognosis; Purines; Receptor, ErbB-2; Survival Rate; Trastuzumab

Ribociclib has received approval in the pre/peri- and postmenopausal disease settings on the basis of the MONALEESA trials. MONALEESA-2 demonstrated that ribociclib plus letrozole significantly improved progression-free survival compared with placebo plus letrozole as first-line therapy in postmenopausal patients with HR-positive, HER2-negative advanced breast cancer. Subsequently, ongoing trials reported significant progression-free survival improvements with ribociclib in combination with either fulvestrant in postmenopausal patients with advanced breast cancer who were either treatment naive or received ≤1 line of prior endocrine therapy in the advanced disease setting (MONALEESA-3) or tamoxifen/nonsteroidal aromatase inhibitor with ovarian function suppression in pre/perimenopausal women (MONALEESA-7). This review summarizes the MONALEESA clinical program. ClinicalTrials.gov identifiers: NCT01958021 (MONALEESA-2), NCT02422615 (MONALEESA-3), NCT02278120 (MONALEESA-7).

Topics: Adolescent; Adult; Aminopyridines; Antineoplastic Agents; Antineoplastic Combined Chemotherapy Protocols; Aromatase Inhibitors; Breast Neoplasms; Cyclin D1; Cyclin-Dependent Kinase 4; Cyclin-Dependent Kinase 6; Estrogens; Female; Fulvestrant; Humans; Letrozole; Middle Aged; Postmenopause; Progression-Free Survival; Purines; Receptor, ErbB-2; Tamoxifen; Young Adult

Determine the efficacy and safety of first-line ribociclib plus letrozole in elderly patients with HR+, HER2- advanced breast cancer.. 668 postmenopausal women with HR+, HER2- advanced breast cancer and no prior systemic therapy for advanced disease were enrolled in the Phase III MONALEESA-2 trial (NCT01958021); 295 patients were aged ≥ 65 years. Patients were randomized to ribociclib (600 mg/day; 3-weeks-on/1-week-off) plus letrozole (2.5 mg/day) or placebo plus letrozole until disease progression, unacceptable toxicity, death, or treatment discontinuation. The primary endpoint was PFS, which was evaluated in elderly (≥ 65 years) and younger (< 65 years) patients. Secondary endpoints included response rates and safety.. Ribociclib plus letrozole significantly improved PFS vs placebo plus letrozole in elderly (hazard ratio: 0.608; 95% CI 0.394-0.937) and younger patients (hazard ratio: 0.523; 95% CI 0.378-0.723). Overall response rates were numerically higher in the ribociclib vs placebo arm, regardless of age. Ribociclib plus letrozole was well tolerated in elderly patients, with the safety profile similar to the overall study population. Nausea, vomiting, alopecia, and diarrhea were > 10% more frequent in the ribociclib plus letrozole vs placebo plus letrozole arm in both subgroups; most events were grade 1/2. In elderly patients, grade 1/2 anemia and fatigue were > 10% more frequent in the ribociclib plus letrozole vs placebo plus letrozole arm and discontinuation rates were similar in both arms.. Addition of ribociclib to letrozole is a valid therapeutic option for elderly patients with HR+, HER2- advanced breast cancer in the first-line setting.

Topics: Aged; Aged, 80 and over; Aminopyridines; Antineoplastic Combined Chemotherapy Protocols; Biomarkers, Tumor; Breast Neoplasms; Disease-Free Survival; Female; Humans; Letrozole; Middle Aged; Nitriles; Purines; Receptor, ErbB-2; Receptors, Estrogen; Receptors, Progesterone; Triazoles

Determine the efficacy and safety of first-line ribociclib plus letrozole in patients with de novo advanced breast cancer.. Postmenopausal women with HR+ , HER2- advanced breast cancer and no prior systemic therapy for advanced disease were enrolled in the Phase III MONALEESA-2 trial (NCT01958021). Patients were randomized to ribociclib (600 mg/day; 3 weeks-on/1 week-off) plus letrozole (2.5 mg/day; continuous) or placebo plus letrozole until disease progression, unacceptable toxicity, death, or treatment discontinuation. The primary endpoint was investigator-assessed progression-free survival; predefined subgroup analysis evaluated progression-free survival in patients with de novo advanced breast cancer. Secondary endpoints included safety and overall response rate.. Six hundred and sixty-eight patients were enrolled, of whom 227 patients (34%; ribociclib plus letrozole vs placebo plus letrozole arm: n = 114 vs. n = 113) presented with de novo advanced breast cancer. Median progression-free survival was not reached in the ribociclib plus letrozole arm versus 16.4 months in the placebo plus letrozole arm in patients with de novo advanced breast cancer (hazard ratio 0.45, 95% confidence interval 0.27-0.75). The most common Grade 3/4 adverse events were neutropenia and leukopenia; incidence rates were similar to those observed in the full MONALEESA-2 population. Ribociclib dose interruptions and reductions in patients with de novo disease occurred at similar frequencies to the overall study population.. Ribociclib plus letrozole improved progression-free survival vs placebo plus letrozole and was well tolerated in postmenopausal women with HR+, HER2- de novo advanced breast cancer.

Topics: Adult; Aged; Aged, 80 and over; Aminopyridines; Antineoplastic Combined Chemotherapy Protocols; Breast; Breast Neoplasms; Chemotherapy-Induced Febrile Neutropenia; Female; Humans; Incidence; Kaplan-Meier Estimate; Letrozole; Leukopenia; Middle Aged; Postmenopause; Progression-Free Survival; Purines; Receptors, Estrogen; Receptors, Progesterone; Response Evaluation Criteria in Solid Tumors; Time Factors

The phase 3 MONALEESA-2 study demonstrated that addition of ribociclib (RIB) to letrozole (LET) significantly improved progression-free survival (PFS) in patients (pts) with hormone receptor-positive (HR+), HER2-negative (HER2-) advanced breast cancer (ABC). Here, we evaluated duration of response (DoR), tumor shrinkage, PFS by treatment-free interval (TFI), and health-related quality of life (HRQoL).. Postmenopausal women (N = 668) with HR+ , HER2- ABC and no prior systemic therapy for ABC were randomized to RIB (600 mg/day; 3 weeks on/1 week off) plus LET (2.5 mg/day; continuous) or placebo (PBO) plus LET. Primary end point was PFS; HRQoL was the secondary end point; DoR was exploratory end point and PFS by TFI was post hoc analysis.. Of 501 pts with measurable disease and confirmed complete or partial response, median DoR was 26.7 months (95% CI, 24.0-NR) in the RIB arm versus 18.6 months (95% CI, 14.8-23.1) in the PBO arm. At 8 weeks, more pts in the RIB arm (32%) versus the PBO arm (17%) experienced best percentage change ≥ 60%. The average pain reduction was greater in the RIB arm (26%) versus the PBO arm (15%). PFS benefit was seen with RIB vs PBO, irrespective of TFI.. RIB plus LET versus PBO plus LET is associated with earlier and more durable tumor response, greater degree of tumor shrinkage and pain reduction, and PFS benefit irrespective of TFI. These data further support RIB plus LET as a first-line treatment option for postmenopausal women with HR+ , HER2- ABC.

Topics: Adult; Aged; Aged, 80 and over; Aminopyridines; Antineoplastic Combined Chemotherapy Protocols; Biomarkers, Tumor; Breast Neoplasms; Female; Humans; Kaplan-Meier Estimate; Letrozole; Middle Aged; Neoplasm Metastasis; Neoplasm Staging; Purines; Quality of Life; Receptor, ErbB-2; Receptors, Estrogen; Receptors, Progesterone; Treatment Outcome; Young Adult

Evaluate patient-reported outcomes (PROs) for postmenopausal women with hormone receptor-positive (HR+), human epidermal growth factor receptor 2-negative (HER2-) advanced breast cancer treated with first-line ribociclib plus letrozole.. In the phase III MONALEESA-2 study (NCT01958021), 668 patients were randomized 1:1 to ribociclib (600 mg/day; 3-weeks-on/1-week-off) plus letrozole (2.5 mg/day) or placebo plus letrozole. PROs were assessed using the European Organisation for Research and Treatment of Cancer core quality-of-life (EORTC QLQ-C30) and breast cancer-specific (EORTC QLQ-BR23) questionnaires. Changes from baseline and time to deterioration in health-related quality of life (HRQoL) were analyzed using linear mixed-effect and stratified Cox regression models, respectively. Exploratory analysis of area-under-the-curve for change from baseline in pain score (AUC-pain) was performed.. On-treatment HRQoL scores were consistently maintained from baseline and were similar between arms. A clinically meaningful (> 5 points) reduction in pain score was observed as early as Week 8 and was maintained up to Cycle 15 in the ribociclib arm. A statistically significant increase in mean AUC-pain was also observed in the ribociclib arm. Scores for all other EORTC QLQ-C30 and EORTC QLQ-BR23 domains were maintained from baseline and were similar between arms.. HRQoL was consistently maintained from baseline in postmenopausal women with HR+, HER2- advanced breast cancer receiving ribociclib plus letrozole and was similar to that observed in the placebo plus letrozole arm. Together with the improved clinical efficacy and manageable safety profile, these PRO results provide additional support for the benefit of ribociclib plus letrozole in this patient population.

Topics: Adult; Aged; Aged, 80 and over; Aminopyridines; Antineoplastic Combined Chemotherapy Protocols; Breast Neoplasms; Female; Humans; Letrozole; Middle Aged; Postmenopause; Purines; Quality of Life; Receptor, ErbB-2; Receptors, Estrogen; Receptors, Progesterone; Young Adult

The phase III MONALEESA-2 study demonstrated significantly prolonged progression-free survival (PFS) and a manageable toxicity profile for first-line ribociclib plus letrozole versus placebo plus letrozole in patients with hormone receptor-positive (HR+), human epidermal growth factor receptor 2-negative (HER2-) advanced breast cancer. Here, we report updated efficacy and safety data, together with exploratory biomarker analyses, from the MONALEESA-2 study.. A total of 668 postmenopausal women with HR+, HER2- recurrent/metastatic breast cancer were randomized (1 : 1; stratified by presence/absence of liver and/or lung metastases) to ribociclib (600 mg/day; 3-weeks-on/1-week-off; 28-day treatment cycles) plus letrozole (2.5 mg/day; continuous) or placebo plus letrozole. The primary end point was locally assessed PFS. The key secondary end point was overall survival (OS). Other secondary end points included overall response rate (ORR) and safety. Biomarker analysis was an exploratory end point.. At the time of the second interim analysis, the median duration of follow-up was 26.4 months. Median PFS was 25.3 months [95% confidence interval (CI) 23.0-30.3] for ribociclib plus letrozole and 16.0 months (95% CI 13.4-18.2) for placebo plus letrozole (hazard ratio 0.568; 95% CI 0.457-0.704; log-rank P = 9.63 × 10-8). Ribociclib treatment benefit was maintained irrespective of PIK3CA or TP53 mutation status, total Rb, Ki67, or p16 protein expression, and CDKN2A, CCND1, or ESR1 mRNA levels. Ribociclib benefit was more pronounced in patients with wild-type versus altered receptor tyrosine kinase genes. OS data remain immature, with 116 deaths observed; 50 in the ribociclib arm and 66 in the placebo arm (hazard ratio 0.746; 95% CI 0.517-1.078). The ORR was 42.5% versus 28.7% for all patients treated with ribociclib plus letrozole versus placebo plus letrozole, respectively, and 54.5% versus 38.8%, respectively, for patients with measurable disease. Safety results, after a further 11.1 months of follow-up, were comparable with those reported at the first analysis, with no new or unexpected toxicities observed, and no evidence of cumulative toxicity.. The improved efficacy outcomes and manageable tolerability observed with first-line ribociclib plus letrozole are maintained with longer follow-up, relative to letrozole monotherapy.. NCT01958021.

Topics: Aged; Aminopyridines; Antineoplastic Combined Chemotherapy Protocols; Biomarkers, Tumor; Breast Neoplasms; Double-Blind Method; Female; Follow-Up Studies; Humans; Letrozole; Liver Neoplasms; Lung Neoplasms; Lymphatic Metastasis; Neoplasm Recurrence, Local; Prognosis; Purines; Receptor, ErbB-2; Receptors, Estrogen; Receptors, Progesterone; Survival Rate

In MONALEESA-2, ribociclib plus letrozole showed improved progression-free survival compared with letrozole alone as first-line treatment for postmenopausal patients with hormone receptor (HR)-positive, HER2-negative, advanced breast cancer. MONALEESA-7 aimed to assess the efficacy and safety of ribociclib plus endocrine therapy in premenopausal women with advanced, HR-positive breast cancer.. This phase 3, randomised, double-blind, placebo-controlled trial was done at 188 centres in 30 countries. Eligible patients were premenopausal women aged 18-59 years who had histologically or cytologically confirmed HR-positive, HER2-negative, advanced breast cancer; an Eastern Cooperative Oncology Group performance status of 0 or 1; measurable disease as per Response Evaluation Criteria in Solid Tumors version 1.1 criteria, or at least one predominantly lytic bone lesion; and had not received previous treatment with cyclin-dependent kinases 4 and 6 inhibitors. Endocrine therapy and chemotherapy in the adjuvant or neoadjuvant setting was permitted, as was up to one line of chemotherapy for advanced disease. Patients were randomly assigned (1:1) via interactive response technology to receive oral ribociclib (600 mg/day on a 3-weeks-on, 1-week-off schedule) or matching placebo with either oral tamoxifen (20 mg daily) or a non-steroidal aromatase inhibitor (letrozole 2·5 mg or anastrozole 1 mg, both oral, daily), all with goserelin (3·6 mg administered subcutaneously on day 1 of every 28-day cycle). Patients and investigators were masked to treatment assignment. Efficacy analyses were by intention to treat, and safety was assessed in all patients who received at least one dose of any study treatment. The primary endpoint was investigator-assessed progression-free survival. MONALEESA-7 is registered with ClinicalTrials.gov, NCT02278120 and is ongoing, but no longer enrolling patients.. Between Dec 17, 2014, and Aug 1, 2016, 672 patients were randomly assigned: 335 to the ribociclib group and 337 to the placebo group. Per investigator's assessment, median progression-free survival was 23·8 months (95% CI 19·2-not reached) in the ribociclib group compared with 13·0 months (11·0-16·4) in the placebo group (hazard ratio 0·55, 95% CI 0·44-0·69; p<0·0001). Grade 3 or 4 adverse events reported in more than 10% of patients in either group were neutropenia (203 [61%] of 335 patients in the ribociclib group and 12 [4%] of 337 in the placebo group) and leucopenia (48 [14%] and four [1%]). Serious adverse events occurred in 60 (18%) of 335 patients in the ribociclib group and 39 (12%) of 337 in the placebo group, of which 15 (4%) and six (2%), respectively, were attributed to the study regimen. 12 (4%) of 335 patients in the ribociclib group and ten (3%) of 337 in the placebo group discontinued treatment because of adverse events. No treatment-related deaths occurred. 11 deaths occurred (five [1%] in the ribociclib group and six [2%] in the placebo group) during or within 30 days after treatment, most of which were due to progression of the underlying breast cancer (three [1%] and six [2%]). The remaining two deaths in the ribociclib group were due to an intracranial haemorrhage in an anticoagulated patient, and a pre-existing wound haemorrhage in another patient.. Ribociclib plus endocrine therapy improved progression-free survival compared with placebo plus endocrine therapy, and had a manageable safety profile in patients with premenopausal, HR-positive, HER2-negative, advanced breast cancer. The combination could represent a new first-line treatment option for these patients.. Novartis.

Topics: Administration, Oral; Adult; Aminopyridines; Antineoplastic Agents, Hormonal; Antineoplastic Combined Chemotherapy Protocols; Breast Neoplasms; Disease-Free Survival; Dose-Response Relationship, Drug; Double-Blind Method; Drug Administration Schedule; Humans; Internationality; Kaplan-Meier Estimate; Letrozole; Middle Aged; Neoplasm Invasiveness; Neoplasm Staging; Premenopause; Prognosis; Proportional Hazards Models; Purines; Survival Analysis; Tamoxifen; Treatment Outcome; Young Adult

Purpose This phase III study evaluated ribociclib plus fulvestrant in patients with hormone receptor-positive/human epidermal growth factor receptor 2-negative advanced breast cancer who were treatment naïve or had received up to one line of prior endocrine therapy in the advanced setting. Patients and Methods Patients were randomly assigned at a two-to-one ratio to ribociclib plus fulvestrant or placebo plus fulvestrant. The primary end point was locally assessed progression-free survival. Secondary end points included overall survival, overall response rate, and safety. Results A total of 484 postmenopausal women were randomly assigned to ribociclib plus fulvestrant, and 242 were assigned to placebo plus fulvestrant. Median progression-free survival was significantly improved with ribociclib plus fulvestrant versus placebo plus fulvestrant: 20.5 months (95% CI, 18.5 to 23.5 months) versus 12.8 months (95% CI, 10.9 to 16.3 months), respectively (hazard ratio, 0.593; 95% CI, 0.480 to 0.732; P < .001). Consistent treatment effects were observed in patients who were treatment naïve in the advanced setting (hazard ratio, 0.577; 95% CI, 0.415 to 0.802), as well as in patients who had received up to one line of prior endocrine therapy for advanced disease (hazard ratio, 0.565; 95% CI, 0.428 to 0.744). Among patients with measurable disease, the overall response rate was 40.9% for the ribociclib plus fulvestrant arm and 28.7% for placebo plus fulvestrant. Grade 3 adverse events reported in ≥ 10% of patients in either arm (ribociclib plus fulvestrant v placebo plus fulvestrant) were neutropenia (46.6% v 0%) and leukopenia (13.5% v 0%); the only grade 4 event reported in ≥ 5% of patients was neutropenia (6.8% v 0%). Conclusion Ribociclib plus fulvestrant might represent a new first- or second-line treatment option in hormone receptor-positive/human epidermal growth factor receptor 2-negative advanced breast cancer.

Topics: Adult; Aged; Aged, 80 and over; Aminopyridines; Antineoplastic Combined Chemotherapy Protocols; Breast Neoplasms; Double-Blind Method; Female; Fulvestrant; Humans; Kaplan-Meier Estimate; Middle Aged; Progression-Free Survival; Purines; Receptor, ErbB-2; Receptors, Estrogen; Receptors, Progesterone

Cyclin D-cyclin-dependent kinase (CDK) 4/6-inhibitor of CDK4/6-retinoblastoma (Rb) pathway hyperactivation is associated with hormone receptor-positive (HR+) breast cancer (BC). This study assessed the biological activity of ribociclib (LEE011; CDK4/6 inhibitor) plus letrozole compared with single-agent letrozole in the presurgical setting.. Postmenopausal women (N = 14) with resectable, HR+, human epidermal growth factor receptor 2-negative (HER2-) early BC were randomized 1:1:1 to receive 2.5 mg/day letrozole alone (Arm 1), or with 400 or 600 mg/day ribociclib (Arm 2 or 3). Circulating tumor DNA and tumor biopsies were collected at baseline and, following 14 days of treatment, prior to or during surgery. The primary objective was to assess antiproliferative response per Ki67 levels in Arms 2 and 3 compared with Arm 1. Additional assessments included safety, pharmacokinetics, and genetic profiling.. Mean decreases in the Ki67-positive cell fraction from baseline were: Arm 1 69% (range 38-100%; n = 2), Arm 2 96% (range 78-100%; n = 6), Arm 3 92% (range 75-100%; n = 3). Decreased phosphorylated Rb levels and CDK4, CDK6, CCND2, CCND3, and CCNE1 gene expression were observed following ribociclib treatment. Ribociclib and letrozole pharmacokinetic parameters were consistent with single-agent data. The ribociclib plus letrozole combination was well tolerated, with no Grade 3/4 adverse events over the treatment.. The results suggest absence of a drug-drug interaction between ribociclib and letrozole and indicate ribociclib plus letrozole may reduce Ki67 expression in HR+, HER2- BC (NCT01919229).

Topics: Aged; Aminopyridines; Antineoplastic Combined Chemotherapy Protocols; Breast Neoplasms; Cyclin D2; Cyclin D3; Cyclin E; Cyclin-Dependent Kinase 4; Cyclin-Dependent Kinase 6; DNA, Neoplasm; Female; Gene Expression; Humans; Ki-67 Antigen; Letrozole; Middle Aged; Neoadjuvant Therapy; Nitriles; Oncogene Proteins; Purines; Receptor, ErbB-2; Receptors, Estrogen; Receptors, Progesterone; Retinoblastoma Protein; Signal Transduction; Triazoles

The inhibition of cyclin-dependent kinases 4 and 6 (CDK4/6) could potentially overcome or delay resistance to endocrine therapy in advanced breast cancer that is positive for hormone receptor (HR) and negative for human epidermal growth factor receptor 2 (HER2).. In this randomized, placebo-controlled, phase 3 trial, we evaluated the efficacy and safety of the selective CDK4/6 inhibitor ribociclib combined with letrozole for first-line treatment in 668 postmenopausal women with HR-positive, HER2-negative recurrent or metastatic breast cancer who had not received previous systemic therapy for advanced disease. We randomly assigned the patients to receive either ribociclib (600 mg per day on a 3-weeks-on, 1-week-off schedule) plus letrozole (2.5 mg per day) or placebo plus letrozole. The primary end point was investigator-assessed progression-free survival. Secondary end points included overall survival, overall response rate, and safety. A preplanned interim analysis was performed on January 29, 2016, after 243 patients had disease progression or died. Prespecified criteria for superiority required a hazard ratio of 0.56 or less with P<1.29×10. The duration of progression-free survival was significantly longer in the ribociclib group than in the placebo group (hazard ratio, 0.56; 95% CI, 0.43 to 0.72; P=3.29×10. Among patients receiving initial systemic treatment for HR-positive, HER2-negative advanced breast cancer, the duration of progression-free survival was significantly longer among those receiving ribociclib plus letrozole than among those receiving placebo plus letrozole, with a higher rate of myelosuppression in the ribociclib group. (Funded by Novartis Pharmaceuticals; ClinicalTrials.gov number, NCT01958021 .).

Topics: Adult; Aged; Aged, 80 and over; Aminopyridines; Antineoplastic Combined Chemotherapy Protocols; Breast Neoplasms; Disease-Free Survival; Double-Blind Method; Drug Administration Schedule; Female; Humans; Kaplan-Meier Estimate; Letrozole; Middle Aged; Neoplasm Staging; Nitriles; Purines; Receptor, ErbB-2; Receptors, Estrogen; Receptors, Progesterone; Triazoles

Cyclin-dependent kinases 4 and 6 (CDK4/6) inhibitors are the new generation drugs that have been started to be used in our clinical practice recently. These drugs have been shown to have better progression-free survival compared to standard therapy in patients with hormone receptor-positive (HR) and human epidermal growth factor receptor 2 (HER-2)-negative breast cancer. The most common side effects of CDK 4-6 inhibitors are neutropenia, nausea, leukopenia, fatigue, and diarrhea. This case demonstrated vortex keratopathy in both eyes, a rare condition in patients with breast cancer treated with ribociclib.. A 68-year-old female patient was diagnosed with locally advanced HR (+)/HER2 (-) breast cancer in March 2015. In June 2021, bone metastases were detected. The patient was started on ribociclib and fulvestrant. After three cycles of ribociclib and fulvestrant treatment, she was admitted with the complaint of blurred vision in her left eye. Slit-lamp biomicroscopy examination revealed subepithelial haze with central subepithelial whorls in both corneas, more in the left eye, and also a mild punctate epithelial staining was observed with the application of fluorescein dye.. Ribociclib treatment was immediately discontinued and no changes were observed in the cornea and vision levels during the one-month follow-up.. Routine and regular follow-up eye examinations in breast cancer patients treated with ribociclib may benefit patients in our daily clinical practice and may help us to detect side effects at an early stage and to manage them more effectively.

Topics: Aged; Aminopyridines; Antineoplastic Combined Chemotherapy Protocols; Breast Neoplasms; Female; Humans; Purines; Receptor, ErbB-2

Cyclin-dependent kinase 4 and 6 inhibitors, ribociclib and palbociclib, are associated with reports of transaminitis and adverse cardiac events.. The patient is a previously healthy 32-year-old female diagnosed with estrogen receptor-positive, progesterone receptor-positive, and human epidermal growth factor 2 negative metastatic breast cancer. From July to September 2021, the patient was initiated on ribociclib followed by palbociclib for metastatic breast cancer. She subsequently experienced two episodes of transaminitis and was diagnosed with cardiomyopathy.. The patient experienced transaminitis 2 weeks after the initiation of ribociclib resulting in discontinuation. When rechallenged with palbociclib, the patient experienced transaminitis within 1 week of initiation, which resulted in discontinuation. Approximately 1 month after palbociclib discontinuation, the patient was diagnosed with congestive heart failure with a left ventricular ejection fraction of 24%.. To our knowledge, there are few case studies investigating cyclin-dependent kinase 4 and 6 inhibitor rechallenge following transaminitis. Prior literature suggests that transaminitis with cyclin-dependent kinase 4 and 6 inhibitors is not a class effect, but this case report suggests otherwise. This report presents a rare case of cardiomyopathy and transaminitis following the administration of cyclin-dependent kinase 4 and 6 inhibitors, ribociclib and palbociclib.

Topics: Adult; Antineoplastic Combined Chemotherapy Protocols; Breast Neoplasms; Cardiomyopathies; Cyclin-Dependent Kinase 4; Female; Humans; Protein Kinase Inhibitors; Stroke Volume; Transaminases; Ventricular Function, Left

To evaluate the difference of progression free survival between the patients using concomitant proton pump inhibitors and non-users in the patients using CDK 4/6 inhibitors with HR + and HER2 negative mBC.. We included 86 patients with HR + and HER 2 negative mBC treated with CDK 4/6 inhibitors in this study. Patients were divided into two categories according to their status of PPI use. The primary end points was progression free survival (PFS). We compared PPI users and non-users.. Forty-five (52.3%) patients used a PPI concomitantly with a CDK 4/6 inhibitor, and 41 (47.7%) did not. The median duration of follow-up was 10.68 (1.94-27.56) months. Of the patients, 50 (58.1%) palbociclib and 36 (41.9%) received ribociclib. The median progression free survival (mPFS) was 10.9 months (95% CI: 7.5-14.27) in the group with concomitant PPI use with a CDK 4/6 inhibitor, whereas the median progression free survival could not be reached in the group without concomitant PPI use (p = 0.04). In addition, concomitant PPI use with palbociclib was associated with a shorter PFS; there was no significant difference between the concomitant PPI users and non-users in terms of PFS in the patients using ribociclib.. Palbociclib and ribociclib are weak base drugs so their bioavailability is pH-dependent. PPIs can affect their solubility and their concentration in the plasma. Therefore, we must avoid concomitant use of PPIs and CDK 4/6 inhibitors. If we need to use concomitant PPI and CDK 4/6 inhibitors, we should prefer ribociclib than palbociclib.

Topics: Aminopyridines; Antineoplastic Combined Chemotherapy Protocols; Breast Neoplasms; Female; Humans; Protein Kinase Inhibitors; Proton Pump Inhibitors; Purines

The cyclin-dependent kinase 4 and 6 (CDK4/6) inhibitors palbociclib, ribociclib, and abemaciclib were approved by the U.S. Food and Drug Administration (FDA) and European Medicine Agency for the treatment of breast cancer between 2015 and 2018. Oral tumor therapeutics extend the options for cancer therapy, but also challenge physicians and patients. The aim of the present work was to establish a semi-automated liquid-chromatography tandem mass spectrometry (LC-MS/MS) method for the simultaneous quantification of abemaciclib, its active metabolites abemaciclib M20 and M2, palbociclib, and ribociclib in human serum. Detuning of ribociclib enabled the development of a simultaneous quantification method for abemaciclib, M20, M2, palbociclib, and ribociclib in the respective relevant concentration ranges based on semi-automated sample preparation with isotope dilution LC-MS/MS. The method was validated according to the guidance of the FDA. The LC-MS/MS method was successfully validated according to FDA and showed inaccuracies ≤ 10.7% and imprecisions ≤ 8.51%. Linearity was given from 20 to 800 ng/mL for abemaciclib, 15-600 ng/mL for M20, 10-400 ng/mL for M2 and palbociclib, and 100-4000 ng/mL for ribociclib. Normalized matrix factors and process efficiency showed no significant matrix effects regardless of the analytes. To demonstrate the applicability of the method, authentic samples were also analyzed. This novel semi-automated LC-MS/MS method covering all previously approved CDK4/6 inhibitors as well as the similarly pharmacologically active metabolites in human serum simultaneously was developed for potential future use in routine analysis in order to improve personalized therapy, patient safety, and treatment success.

Topics: Aminopyridines; Breast Neoplasms; Chromatography, Liquid; Cyclin-Dependent Kinase 4; Cyclin-Dependent Kinase 6; Drug Monitoring; Female; Humans; Protein Kinase Inhibitors; Tandem Mass Spectrometry

Cyclin-dependent kinase (CDK) 4/6 inhibitors have shown a different adverse effect. In this case, persistent grade 3 hepatoxicity was observed after ribociclib. Therefore, ribociclib therapy was stopped, and then palbociclib was introduced. Transaminase levels returned to normal by switching to palbociclib therapy.. 71-year-old postmenopausal female patient with luminal subtypes of metastatic breast cancer treated with ribociclib.. Grade 3 hepatotoxicity secondary to ribociclib developed. She was successfully treated with palbociclib 125 mg.. In our case, palbociclib was started with a full dose, to increase treatment success. Starting with a 125 mg dose was not cause any toxicity. Nevertheless, laboratory follow-up is required in terms of neutropenia and increased transaminases.

Topics: Aged; Aminopyridines; Antineoplastic Combined Chemotherapy Protocols; Breast Neoplasms; Chemical and Drug Induced Liver Injury; Drug-Related Side Effects and Adverse Reactions; Female; Humans; Protein Kinase Inhibitors; Purines

This study found that CDK4/6 inhibitors rapidly reached many eligible patients with metastatic breast cancer and were adopted gradually over time in the Netherlands. Adoption of innovative medicines may be further optimized, and better transparency of the availability of new medicines during different phases of the postapproval access pathway is needed.. This cohort study reviewed approval and reimbursement decisions of the CDK4/6 inhibitors palbociclib, ribociclib, and abemaciclib and estimated the number of patients with metastatic breast cancer who were eligible for these medicines compared with the actual use in clinical practice. The study used nationwide claims data that were obtained from the Dutch Hospital Data. Claims and early access data for patients with hormone receptor-positive and ERBB2 (formerly HER2)-negative metastatic breast cancer who were treated with CDK4/6 inhibitors from November 1, 2016, to December 31, 2021, were included.. The number of new cancer medicines that are being approved by regulatory agents is increasing exponentially. Yet little is known about the pace at which these medicines reach eligible patients in daily clinical practice during different phases of the postapproval access pathway.. Description of the postapproval access pathway, monthly number of patients who were treated with CDK4/6 inhibitors in clinical practice, and estimated number of patients who were eligible for treatment. Aggregated claims data were used, and patient characteristics and outcomes data were not collected.. To describe the entire postapproval access pathway of cyclin-dependent kinase 4/6 (CDK4/6) inhibitors in the Netherlands, from regulatory approval to reimbursement and to investigate the adoption of these medicines in clinical practice among patients with metastatic breast cancer.. Three CDK4/6 inhibitors have received European Union-wide regulatory approval for the treatment of HR-positive and ERBB2-negative metastatic breast cancer since November 2016. In the Netherlands, the number of patients who have been treated with these medicines increased to approximately 1847 (based on 1 624 665 claims over the entire study period) from approval to the end of 2021. Reimbursement for these medicines was granted between 9 and 11 months after approval. While awaiting reimbursement decisions, 492 patients received palbociclib, the first approved medicine of this class, via an expanded access program. By the end of the study period, 1616 patients (87%) were treated with palbociclib, whereas 157 patients (7%) received ribociclib, and 74 patients (4%) received abemaciclib. The CKD4/6 inhibitor was combined with an aromatase inhibitor in 708 patients (38%) and with fulvestrant in 1139 patients (62%). The pattern of use over time appeared to be somewhat lower compared with the estimated number of eligible patients (1847 vs 1915 in December 2021), especially in the first 2.5 years after approval.

Topics: Breast Neoplasms; Cohort Studies; Cyclin-Dependent Kinase 4; Cyclin-Dependent Kinase 6; Female; Humans; Netherlands; Protein Kinase Inhibitors

Cyclin-dependent kinase 4 and 6 (CDK4/6) inhibitors improve progression-free survival when combined with endocrine therapies in patients with hormone receptor-positive/human epidermal growth factor receptor 2-negative metastatic breast cancer. However, the comparative cost effectiveness of utilizing three US Food and Drug Administration-approved CDK4/6 inhibitors is unknown. Therefore, we aimed to evaluate the cost effectiveness of individual CDK4/6 inhibitors (palbociclib, ribociclib, abemaciclib) with letrozole versus letrozole monotherapy in the first-line treatment of hormone receptor-positive/human epidermal growth factor receptor 2-negative metastatic breast cancer in the USA.. We constructed a Markov-based decision-analytic model to evaluate the cost effectiveness of CDK4/6 inhibitors plus endocrine therapies over a 40-year lifetime from a third-party payer perspective. The model incorporated health states (progression-free disease, progressive disease, and death), major adverse events (neutropenia), and cancer-specific and all-cause mortality. Using clinical efficacy and quality-of-life scores (utility) data from clinical trials, we estimated quality-adjusted life-years (QALYs) and incremental cost-effectiveness ratios using Medicare charges reported in US dollars per 2022 valuation and a discount rate of 3% applied to costs and outcomes. We performed deterministic and probabilistic sensitivity analyses to evaluate parametric and decision uncertainty.. Compared to letrozole, the model estimated an increase of 5.72, 5.87, and 6.39 in QALYs and costs of $799,178, $788,168, and $741,102 in combining palbociclib, ribociclib, and abemaciclib plus letrozole, respectively. Palbociclib or ribociclib plus letrozole were dominated by abemaciclib plus letrozole. Compared with letrozole, abemaciclib plus letrozole resulted in an incremental cost-effectiveness ratio of $457,538 per QALY with an incremental cost of $553,621 and an incremental QALY gain of 1.21. The results were sensitive to the cost of abemaciclib, disease progression utility, and patients' age.. At a willingness to pay of $100,000/QALY gained, our model predicts that combining CDK4/6 inhibitors plus letrozole is not cost effective with a marginal increase in QALYs at a high cost. Lowering the cost of these drugs or identifying patients who can receive maximal benefit from CDK4/6 inhibitors would improve the value of this regimen in patients.

Topics: Aged; Antineoplastic Combined Chemotherapy Protocols; Breast Neoplasms; Cost-Effectiveness Analysis; Cyclin-Dependent Kinase 4; Female; Humans; Letrozole; Medicare; Postmenopause; Receptor, ErbB-2; United States

CDK4/6 inhibitors (ribociclib, palbociclib and abemaciclib) are 1st line therapy in metastatic breast cancer (MBC). No comparative data exists between agents regarding toxicity or efficacy.. A retrospective study was performed at our tertiary referral centre evaluating patients on a CDK4/6 inhibitor for MBC between July 2017 and December 2021. Toxicity was evaluated along with variability in full blood counts and liver function over the first 12 weeks of therapy.. Two hundred and seventeen patients were treated (palbociclib 59%, abemaciclib 25% and ribociclib 16%). 86% received the agent as 1st line therapy. Most patients were white women with a median age of 61 years (32-95) and ECOG 0/1. Twelve patients were switched to an alternative CDK4/6 inhibitor due to toxicity and two did not tolerate this. Toxicity profiles of agents were consistent with published trials. However, there was greater overlap in hepatitis, diarrhoea and bone marrow suppression. Blood results indicated a minimum of four weeks treatment before development of neutropenia. Forty percent of patients went onto have subsequent lines of therapy. The progression-free survival per agent was palbociclib 27.9 months (95% CI 23-32.5), ribociclib 29 months (95% CI 21.5-37.0) and abemaciclib 20.6 months (95% CI 15.0-26.0). The overall survival was palbociclib 38.0 months (95% CI 33.5-42.5), ribociclib 33.9 months (95% CI 26.7-41.1) and abemaciclib 27.3 months (95% CI 22.5-32.1).. Toxicity across CDK4/6 inhibitors overlaps. The optimal sequence of therapies post CDK4/6 inhibitors remains unknown but rechallenge with an alternative agent is possible.

Topics: Adult; Aged; Aged, 80 and over; Breast Neoplasms; Cyclin-Dependent Kinase 4; Female; Humans; Middle Aged; Protein Kinase Inhibitors; Retrospective Studies

Topics: Antineoplastic Combined Chemotherapy Protocols; Breast Neoplasms; Female; Humans; Proton Pump Inhibitors; Retrospective Studies

Newly designed 4 - aminoquinazoline derivatives (5a-f, 6a, b, 7, 8, 9, 10a-c, 11a, b, 12a, b and 13a, b) have been synthesized and evaluated for their potential multitarget anticancer activities, apoptotic and anti-proliferative effects. Thereupon, in vitro cytotoxic activities of all the synthesized compounds were screened against NCI 60 human cancer cell lines (nine subpanels) at NCI, USA. Successfully, 2-morpholino-N-(quinazolin-4-yl) acetohydrazide 5e was granted an NSC code, owing to its significant potency and broad spectrum of activity against various cancer cell lines; leukemia K-562, non-small cell lung cancer NCI-H522 cells, colon cancer SW-620, melanoma LOX IMVI, MALME-3M, renal cancer RXF 393, ACHN and breast cancer MDA-MB231/ATCC (GI% = 99.6, 161, 126.03, 90.22, 174.47, 139.7, 191 and 97, respectively). Compound 5e showed the best inhibitory activity (GI

Topics: Antineoplastic Agents; Breast Neoplasms; Carcinoma, Non-Small-Cell Lung; Cell Line, Tumor; Cell Proliferation; Drug Screening Assays, Antitumor; ErbB Receptors; Female; Humans; Kidney Neoplasms; Lapatinib; Lung Neoplasms; Melanoma; Molecular Docking Simulation; Molecular Structure; Structure-Activity Relationship

Hepatotoxicity is observed due to cyclin-dependent kinase (CDK4/6) inhibitors used to treat hormone receptor-positive metastatic breast cancer. However, it should not be ignored that denosumab may be hepatotoxic, although it is rare.. A 73-year-old female patient with breast cancer with axillary lymph node, adrenal gland and bone metastases was started on ribociclib letrozole and denosumab treatment. Ribociclib treatment was discontinued due to grade 4 hepatotoxicity during treatment, but liver function tests did not decrease. After discontinuation of denosumab treatment, alanine aminotransferase and aspartate aminotransferase values regressed to baseline values.. Despite the discontinuation of ribociclib treatment, other causes of liver toxicity were investigated due to persistence of hepatic transaminases and elevation. Autoimmune hepatitis markers were negative. Hepatobiliary USG did not reveal any pathological findings except hepatosteatosis. Liver biopsy was performed to determine the etiology. Pathology result was compatible with acute hepatocellular damage (in favor of toxic hepatitis). A decrease in liver values was detected after discontinuation of denosumab treatment.. Although cases with improvement in liver enzymes have been reported after discontinuation of ribociclib, no improvement in hepatotoxicity was observed in our case. Since the liver biopsy was toxic hepatitis, it was thought that other drugs used by the patient might cause this toxicity, and a significant decrease was observed in liver values after discontinuation of denosumab. Denosumab-induced liver toxicity is very rare, and there are only a limited number of cases in the literature.

Topics: Aged; Antineoplastic Combined Chemotherapy Protocols; Breast Neoplasms; Chemical and Drug Induced Liver Injury; Denosumab; Female; Humans; Letrozole; Receptor, ErbB-2

By the end of 2020, there were more than 8 million women alive who had received a breast cancer diagnosis in the previous 5 years, making it the most prevalent neoplasia in the world. About 70% of breast-cancer cases present positivity for estrogen and/or progesterone receptors and a lack of HER-2 overexpression. Endocrine therapy has traditionally been the standard of care for ER-positive and HER-2-negative metastatic breast cancer. In the last 8 years, the advent of CDK4/6 inhibitors has shown that adding them to endocrine therapy doubles PFS. As a result, this combination has become the gold standard in this setting. Three CDK4/6 inhibitors have been approved by the EMA and the FDA: abemaciclib, palbociclib, and ribociclib. They all have the same indications, and it is at each physician's discretion to choose one or the other. The aim of our study was to perform a comparative efficacy analysis of the three CDK4/6i using real-world data. We selected patients diagnosed with endocrine-receptor-positive and HER2-negative breast cancer who were treated with all three CDK4/6i as first-line therapy at a reference center. After 42 months of retrospective follow up, abemaciclib was associated with a significant benefit in terms of progression-free survival in endocrine-resistant patients and in the population without visceral involvement. In our real-world cohort, we found no other statistically significant differences among the three CDK4/6 inhibitors.

Topics: Antineoplastic Combined Chemotherapy Protocols; Breast Neoplasms; Cyclin-Dependent Kinase 4; Cyclin-Dependent Kinase 6; Female; Humans; Protein Kinase Inhibitors; Retrospective Studies

Cyclin-dependent kinase (CDK) 4/6 inhibitors are widely used in combination with aromatase inhibitors or fulvestrant for the treatment of locally advanced or metastatic hormone receptor-positive (HR+), human epidermal growth factor 2-negative (HER2-) breast cancer. Hematological toxicities (e.g. neutropenia, thrombocytopenia, anemia, lymphopenia, or febrile neutropenia), infections, decreased appetite, exhaustion, headache, dizziness, cough, nausea, vomiting, diarrhea, alopecia, rash, increased alanine aminotransferase and aspartate aminotransferase levels, and QT interval prolongation are frequent side effects associated with the use of CDK 4/6 inhibitors. However, to our knowledge, no case of hallucination associated with CDK 4/6 inhibitor use has been described in the English-language literature.. We report a case of a 72-year-old woman with metastatic breast cancer who developed visual hallucinations after receiving ribociclib, a CDK 4/6 inhibitor, and letrozole for 3 days. Cranial imaging and blood tests did not reveal the cause of the hallucinations.. The visual hallucinations completely resolved within 4 days after the ribociclib treatment was terminated. The patient received only letrozole for 2 weeks, and ribociclib treatment was restarted 2 weeks later. Visual hallucinations recurred on the third day of treatment, and ribociclib treatment was discontinued again. The patient recovered completely from visual hallucinations 4 days after discontinuation. Subsequently, treatment was continued with letrozole and palbociclib, another CDK 4/6 inhibitor. Hallucinations did not recur during follow-up.. To our knowledge, this is the first reported case of hallucinations caused by ribociclib; notably, it shows that symptoms may develop in the early stage of treatment.

Topics: Aged; Antineoplastic Combined Chemotherapy Protocols; Breast Neoplasms; Female; Hallucinations; Humans; Letrozole; Neoplasm Recurrence, Local; Receptor, ErbB-2

As cyclin-dependent kinase 4/6 (CDK 4/6) inhibitors, which play a crucial role in the cell cycle, palbociclib and ribociclib are two novel drugs that are recently being used in the treatment of breast cancer. Despite targeting the same pathway, these agents have different molecular activities and processes. KI-67 is known to play a significant role in cell proliferation that has been related to prognosis. This study investigated the impact of palbociclib, ribociclib, and KI-67 on toxicity and survival in breast cancer treatment.. The study included 140 breast cancer patients in total. Patients were divided into groups based on the use of different CDK inhibitors and KI-67 values. Mortality, progression, treatment response rates, frequency, and severity of adverse events were assessed retrospectively.. The patients in our study had an average age of 53.62±12.71 years, and 62.9% of them were diagnosed at an early stage. 34.3% (n=48) of the patients progressed after receiving treatment, while 19.3% (n=27) of the patients died. The median follow-up time was 576 days, the maximum follow-up time was 1,471 days, and the median time to progression was 301 days (min=28-max=713). Mortality, progression, and treatment response rate between two different CDK inhibitors or KI-67 groups revealed no statistically significant differences.. Our data show a comparison between the effectiveness of palbociclib and ribociclib, and no noticeable difference is found in breast cancer patients' survival, progression, or severity of adverse effects. Likewise, there is no meaningful difference in KI-67 expression subgroups between progression and survival following treatment.

Topics: Adult; Aged; Antineoplastic Combined Chemotherapy Protocols; Breast Neoplasms; Cyclin-Dependent Kinase 4; Cyclin-Dependent Kinase 6; Cyclin-Dependent Kinase Inhibitor Proteins; Female; Humans; Ki-67 Antigen; Middle Aged; Protein Kinase Inhibitors; Retrospective Studies

Drug-induced subacute cutaneous lupus erythematosus (DI-SCLE) has been associated with drugs with different mechanisms of action, including anti-hypertensives, tumour necrosis factor-α inhibitors and even some chemotherapy medicines. In the last years, a few reports have been described in patients treated with cyclin-dependent kinase (CDK) 4/6 inhibitors, palbociclib and abemaciclib.. Here, we describe a case of DI-SCLE in association with ribociclib and exemestane in a woman diagnosed with metastatic breast cancer.. Topical mometasone was prescribed for two weeks with complete resolution of lesions, also abemaciclib was substituted for ribociclib, and the patient had stable disease with no relapse of DI-SCLE.. To our knowledge, this is the first report of ribociclib-induced SCLE but based on the DI-SCLE reported cases associated others CDK4/6 inhibitors, the role of this family of drugs in dermatopathology must be further investigated.

Topics: Breast Neoplasms; Female; Humans; Lupus Erythematosus, Cutaneous; Neoplasm Recurrence, Local

Ribociclib in combination with endocrine therapy (ET) is a globally approved treatment option for patients with hormone receptor-positive (HR+)/human epidermal growth factor receptor 2-negative (HER2-) advanced breast cancer (ABC) and has demonstrated significantly improved overall survival (OS) in 3 phase 3 clinical trials. To justify the dose regimen and dose modification scheme for patients with ABC, the pharmacokinetic (PK), safety, and efficacy data of ribociclib were analyzed. The data of several phase 1-3 clinical studies were pooled and analyzed to characterize the relationship between exposure (dose or PK) and efficacy (progression-free survival (PFS), time to response, and OS) or safety (neutropenia and QT interval prolongation). The exposure-efficacy analysis showed no apparent relationship between ribociclib exposure and efficacy (PFS and OS), and efficacy analysis by dose reduction showed that patients with ABC continued to benefit from the treatment following dose reduction, supporting the starting dose of 600 mg as well as dose reductions to 400 and 200 mg. The exposure-safety analysis showed that neutropenia and QT prolongation are related to ribociclib exposure that can be effectively managed by individualized dose modification (dose reduction/interruption). Collective evidence from the exposure-response analyses for efficacy and safety support the use of ribociclib in combination with ET partners at the starting dose of 600 mg, and also the effectiveness of individualized dose reductions in managing safety, while maintaining efficacy, in patients with HR+/HER2- ABC. This analysis illustrates the utility of quantitative assessment in justifying dose selection and dose modification for oncology medicines.

Topics: Aminopyridines; Antineoplastic Combined Chemotherapy Protocols; Breast Neoplasms; Female; Humans; Neutropenia; Purines; Receptor, ErbB-2

The phase III MONALEESA trials tested the efficacy and safety of the cyclin-dependent kinase (CDK)4/6 inhibitor ribociclib with different endocrine therapy partners as first- or second-line treatment of hormone receptor-positive/human epidermal growth factor receptor 2-negative advanced breast cancer (ABC). Using the largest pooled biomarker dataset of the CDK4/6 inhibitor ribociclib in ABC to date, we identified potential biomarkers of response to ribociclib.. Baseline circulating tumour DNA from patients in the MONALEESA trials was assessed using next-generation sequencing. An analysis of correlation between gene alteration status and progression-free survival (PFS) was carried out to identify potential biomarkers of response to ribociclib.. Multiple frequently altered genes were identified. Alterations in ERBB2, FAT3, FRS2, MDM2, SFRP1, and ZNF217 were associated with a greater PFS benefit with ribociclib versus placebo. Patients with high tumour mutational burden (TMB) and with ANO1, CDKN2A/2B/2C, and RB1 alterations exhibited decreased sensitivity to ribociclib versus placebo.. Although exploratory, these results provide insight into alterations associated with the improved response to ribociclib treatment and may inform treatment sequencing in patients with actionable alterations following progression on CDK4/6 inhibitors. Validation of potential biomarkers identified here and development of prospective trials testing their clinical utility are warranted.. NCT01958021, NCT02422615, NCT02278120.

Topics: Aminopyridines; Antineoplastic Combined Chemotherapy Protocols; Breast Neoplasms; Female; Humans; Letrozole; Prospective Studies; Receptor, ErbB-2

In this study, the toxicities and management of palbociclib and ribociclib in older patients (≥65 years) with metastatic breast cancer patients were investigated.. Among older patients receiving palbociclib and ribociclib, Geriatric 8 (G8) and Groningen Frailty Index were used to evaluate frailty status. Dose modifications, drug withdrawal and other serious adverse events (SAEs) were recorded and analyzed according to baseline patient characteristics.. A total of 160 patients from 28 centers in Turkey were included (palbociclib = 76, ribociclib = 84). Forty-three patients were ≥ 75 years of age. The most common cause of first dose modification was neutropenia for both drugs (97% palbociclib, 69% ribociclib). Liver function tests elevation (10%) and renal function impairment (6%) were also causes for ribociclib dose modification. Drug withdrawal rate was 3.9% for palbociclib and 6% for ribociclib. SAEs were seen in 11.8% of those taking palbociclib and 15.5% of those on riboclib. An ECOG performance status of ≥2 and being older than 75 years were associated with dose reductions. Severe neutropenia was more common in patients with non-bone-only metastatic disease, those receiving treatment third-line therapy or higher, coexistance of non-neutropenic hematological side effects (for ribociclib). Neutropenia was less common among patients with obesity.. Our results show that it can be reasonable to start palbociclib and ribociclib at reduced dose in patients aged ≥75 years and/or with an ECOG performance status ≥2.

Topics: Aged; Antineoplastic Combined Chemotherapy Protocols; Breast Neoplasms; Female; Frailty; Humans; Neutropenia; Prospective Studies; Protein Kinase Inhibitors

The NATALEE study showed a significant benefit in invasive disease-free survival (iDFS) for patients with HR+/HER2- early breast cancer (eBC) at intermediate and high risk of recurrence who were treated with the CDK4/6 inhibitor Ribociclib in combination with endocrine therapy (ET). This retrospective study aims to apply the NATALEE inclusion criteria to a representative real-world cohort to estimate the proportion of HR+/HER2- breast cancer patients eligible for adjuvant Ribociclib therapy. Patients who underwent full surgical treatment for eBC between January 2018 and December 2020 at two large German university breast cancer centers (University of Ulm, University of Tuebingen) were included. Descriptive statistics were used to characterize the patient population eligible for Ribociclib treatment based on the NATALEE study's inclusion criteria. Out of 2384 enrolled patients, 1738 had HR+/HER2- eBC, of whom 43% (747/1738) met the NATALEE inclusion criteria. Of note, these patients were older, received less chemotherapy and presented with less advanced tumor stages compared to the NATALEE study cohort. Additionally, compared to the NATALEE study cohort, fewer patients had lymph node involvement (72.4% vs. 88.7%). Our analysis suggests that approximately 43% of all HR+/HER2- breast cancer patients will qualify for Ribociclib treatment. Given the numerous treatment options for patients with HR+/HER2- eBC, as well as the differences between the NATALEE cohort and patients in the real-world clinical setting, future analyses will be needed to determine which patients would benefit most from adjuvant CDK4/6 inhibitor treatment.

Topics: Antineoplastic Combined Chemotherapy Protocols; Breast Neoplasms; Clinical Relevance; Female; Humans; Receptor, ErbB-2; Retrospective Studies

Ribociclib, one of the cyclin-dependent kinases (CDK) 4 and 6 inhibitors, in combination with endocrine therapies has been approved in the treatment of hormonal receptor positive, HER-2 negative metastatic breast cancer worldwide. Long-term usage of ribociclib with concomitant drugs, potential drug-drug interaction may develop which can limit the therapeutic value of CDK4/6 inhibitor.. A 62-year-old with history of non-insulin dependent diabetic, dyslipidemia, and essential hypertension was diagnosed with HR-positive, HER-2 negative metastatic breast cancer and treated with fulvestrant plus ribociclib. Four weeks after administration, elevated serum creatinine was observed, and then severe lactic acidosis with acute respiratory failure was subsequently reported. Ribociclib and fulvestrant were temporarily discontinued. Three days after renal replacement therapy, her clinical was stabilized. Combination ribociclib with metformin resulted in high plasma metformin levels and dangerous consequences. Hence, special precaution should be considered during concomitant treatment with sensitive transporter substrates.. Metformin associated lactic acidosis may potentially occur after combination with ribocilib, an uncommon but lethal complication from the interaction of these drugs, especially in patients who had preexisting renal impairment.

Topics: Acidosis, Lactic; Aminopyridines; Breast Neoplasms; Drug Interactions; Female; Fulvestrant; Humans; Metformin; Middle Aged; Purines; Renal Insufficiency

Inhibitors of the cyclin-dependent kinases 4 and 6 (CDK4/6i) have significantly improved clinical outcomes in patients with advanced hormone receptor-positive (HR+) breast cancer and have demonstrated favourable antitumour immune responses in preclinical studies.. Here, we investigated peripheral immune responses to ribociclib in patients with metastatic HR+ breast cancer as a preplanned exploratory subanalysis of the RIBECCA trial (NCT03096847). Peripheral blood mononuclear cells were subjected to immune cell profiling, gene expression analysis of immune-related signatures, and deep T cell receptor profiling before treatment started and after 12 weeks of treatment with ribociclib.. Gene expression analysis revealed an upregulation of signatures associated with an activated adaptive immune system and a decrease in immunosuppressive cytokine signalling during treatment with ribociclib. Profiling of peripheral immune cell subpopulations showed a decrease in Treg cell frequencies, which was associated with treatment response. Furthermore, induction of CD4+ naive T cells could be seen, whereas effector and memory T cell populations remained largely unchanged. Correspondingly, T cell repertoire diversity remained mostly unchanged during treatment, although an increase in clonality could be observed in single patients.. We show that treatment with ribociclib has significant effects on the peripheral innate and adaptive immune response in patients with HR+ breast cancer. Our data suggest that these effects lead to an activation of an already existing immune response rather than a de novo induction and make a strong case for future combination strategies of CDK4/6i with immunotherapies to enhance the adaptive immune response in HR+ breast cancer.

Topics: Aminopyridines; Antineoplastic Combined Chemotherapy Protocols; Breast Neoplasms; Female; Humans; Immunity; Leukocytes, Mononuclear; Purines; Receptor, ErbB-2

HR+/HER2- metastatic breast cancer (MBC) is one of the most common and life-threatening conditions diagnosed in women. The endocrine therapy using an orally active CDK4/6 inhibitor, ribociclib (RB), is the most intriguing approach for treating HR+/HER2- MBC. However, the repeated three to six cycles of multiple dosing and non-targeted distribution of RB led to severe neutropenia; hepatobiliary, gastrointestinal, and renal toxicities, and QT interval prolongation. Here, a novel organic solvent-free HA-PVA-PVP (hyaluronic acid-polyvinyl alcohol-polyvinyl pyrrolidone) composed of a microneedle (MN) array is formulated to deliver RB, integrated with amphiphilic conjugated polymer (HA-GMS)-anchored ultradeformable transfersomes. This unique MN array efficiently crafts microchannels in the skin, allowing HA-RB-Ts to internalize into the tumor cells through lymphatic and systemic absorption and interact with CD44 both spatially and temporally with an amplification of drug release time up to 6-folds. The pharmacokinetic and tissue distribution studies portray drug concentrations within the therapeutic window as long as 48 h, facilitating thrice-a-week frequency with the lower dose, and rule out severe toxicities, with a significant reduction in 8.3-fold RB concentration in vital organs that ultimately enhances the survival rate. Thus, the novel MN system pursues a unique embeddable feature and offers an effective, self-administrable, biodegradable, and chronic treatment option for patients requiring long-term cancer treatments.

Topics: Aminopyridines; Breast Neoplasms; Drug Delivery Systems; Female; Humans; Hyaluronan Receptors; Purines

The current investigation is on the explicit development and evaluation of nanostructured lipidic carriers (NLCs) through the oral route to overcome the inherent lacuna of chemotherapeutic drug, in which Ribociclib (RBO) was used for breast cancer to diminish the bioavailability issue.. The RBO-NLCs were prepared using the solvent evaporation method and optimized method by the Box-Behnken design (BBD). Various assessment parameters characterized the optimized formulation and their. The prepared NLCs exhibited mean particle size of 114.23 ± 2.75 nm, mean polydispersity index of 0.649 ± 0.043, and high entrapment efficiency of 87.7 ± 1.79%. The structural analysis by TEM revealed the spherical size of NLCs and uniform drug distribution. An. The

Topics: Administration, Oral; Aminopyridines; Animals; Biological Availability; Breast Neoplasms; Cell Line, Tumor; Drug Carriers; Excipients; Female; Intestinal Absorption; Nanostructures; Purines; Rats; Rats, Wistar

The CDK4/6 inhibitors (CDKi) palbociclib, ribociclib, and abemaciclib are currently approved in combination with anti-estrogen therapy for the treatment of advanced and/or metastatic hormone receptor-positive/HER2-neu-negative breast cancer patients. Given the high incidence of bone metastases in this population, we investigated and compared the potential effects of palbociclib, ribociclib, and abemaciclib on the breast cancer bone microenvironment. Primary osteoclasts (OCs) and osteoblasts (OBs) were obtained from human monocyte and mesenchymal stem cells, respectively. OC function was evaluated by tartrate-resistant acid phosphatase assay and real-time PCR; OB activity was assessed by an alizarin red assay. OB/breast cancer co-culture models were generated via the seeding of MCF-7 cells on a layer of OBs, and tumor cell proliferation was analyzed using flow cytometry. Here, we showed that ribociclib, palbociclib, and abemaciclib exerted similar inhibitory effects on the OC differentiation and expression of bone resorption markers without affecting OC viability. On the other hand, the three CDKi did not affect the ability of OB to produce bone matrix, even if the higher doses of palbociclib and abemaciclib reduced the OB viability. In OB/MCF-7 co-culture models, palbociclib demonstrated a lower anti-tumor effect than ribociclib and abemaciclib. Overall, our results revealed the direct effects of CDKi on the tumor bone microenvironment, highlighting differences potentially relevant for clinical practice.

Topics: Aminopyridines; Benzimidazoles; Breast Neoplasms; Cyclin-Dependent Kinase 4; Cyclin-Dependent Kinase 6; Cyclin-Dependent Kinase Inhibitor Proteins; Female; Humans; Piperazines; Protein Kinase Inhibitors; Purines; Pyridines; Tumor Microenvironment

Topics: Aminopyridines; Breast Neoplasms; Female; Genomics; Humans; Purines

Approximately 20-33% of all cancer patients are treated with acid-reducing agents (ARAs), most commonly proton pump inhibitors (PPIs), to reduce gastroesophageal reflux disease symptoms. Palbociclib and ribociclib are weak bases so their solubility depends on different pH. The solubility of palbociclib dramatically decreases to < 0.5 mg/ml when pH is above 4,5 but ribociclibs' solubility decreases when pH increases above 6,5. In the current study, we aimed to investigate the effects of concurrent PPIs on palbociclib and ribociclib efficacy in terms of progression-free survival in metastatic breast cancer (mBC) patients.. We enrolled hormone receptor-positive, HER2-negative mBC patients treated with endocrine treatment (letrozole or fulvestrant) combined palbociclib or ribociclib alone or with PPI accompanying our observational study. During palbociclib/ribociclib therapy, patients should be treated with "concurrent PPIs" defined as all or more than half of treatment with palbociclib/ribociclib, If no PPI was applied, it was defined as 'no concurrent PPI', those who used PPI but less than half were excluded from the study. All data was collected from real-life retrospectively.. Our study included 217 patients, 105 of whom received palbociclib and 112 received ribociclib treatment. In the study population CDK inhibitor treatment was added to fulvestrant 102 patients ( 47%), to letrozole 115 patients (53%). In the Palbociclib arm fulvestrant/letrozole ratio was 53.3/46.7%, in the ribociclib arm it was 41.07/58.93%. Of 105 patients who received palbociclib, 65 were on concomitant PPI therapy, 40 were not. Of the 112 patients who received ribociclib, 61 were on concomitant PPI therapy, 51 were not. In the palbociclib group, the PFS of the patients using PPIs was shorter than the PFS of the patients not using (13.04 months vs. unreachable, p < 0.001). It was determined that taking PPIs was an independent predictor of shortening PFS (p < 0.001) in the multivariate analysis, In the ribociclib group, the PFS of the patients using PPIs was shorter than the PFS of the patients not using (12.64 months vs. unreachable, p = 0.003). It was determined that taking PPIs was single statistically independent predictor of shortening PFS (p = 0.003, univariate analysis).. Our study demonstrated that concomitant usage of PPIs was associated with shorter PFS in mBC treated with both ribociclib and especially palbociclib. If it needs to be used, PPI selection should be made carefully and low-strength PPI or other ARAs (eg H2 antagonists, antacids) should be preferred.

Topics: Aminopyridines; Antineoplastic Agents; Breast Neoplasms; Drug Interactions; Female; Fulvestrant; Humans; Letrozole; Piperazines; Protein Kinase Inhibitors; Proton Pump Inhibitors; Purines; Pyridines; Receptor, ErbB-2; Retrospective Studies

In this study, we evaluate the cost and outcomes of cyclin-dependent kinase 4/6 inhibitors (CDK4/6i) plus fulvestrant, fulvestrant alone, and conventional chemotherapy as the second-line therapy for hormone receptor-positive (HR+), human epidermal growth factor receptor 2-negative (HER2-) metastatic breast cancer (MBC) in India.. Using a Markov model, the clinical effectiveness of managing HR+, HER2- MBC in postmenopausal women with either a CDK4/6i (either ribociclib or palbociclib) and fulvestrant, fulvestrant alone, and chemotherapy (single-agent paclitaxel or capecitabine) was measured in terms of quality-adjusted life-years (QALYs). The costs were estimated from two different points of view: scenario I, as per the prevailing market prices of the drugs; and scenario II, as per the reimbursement rates set up by the publicly financed national health insurance scheme. Incremental cost per QALY gained with a given treatment option was compared against the next best alternative and was assessed for cost effectiveness using a threshold of 1-time the per capita gross domestic product (GDP) in India from a societal perspective.. In scenario I, an MBC patient was found to incur a lifetime cost of Indian Rupees (₹) 2.54 million ($34,644), ₹2.53 million ($34,496), ₹512,598 ($6,984), ₹326,026 ($4,442) and ₹237,115 ($3,230) for the ribociclib and palbociclib combination arms, fulvestrant monotherapy, single-agent paclitaxel and the single-agent capecitabine treatment arms, respectively. The lifetime cost for CDK4/6i (ribociclib and palbociclib) combination therapy, fulvestrant monotherapy, paclitaxel, and capecitabine arms was estimated to be ₹1.94 million ($26,459), ₹1.92 million ($26,220), ₹315,387 ($4,296), ₹187,392 ($2,553) and ₹153,263 ($2,088), respectively, in scenario II. The mean QALYs lived per MBC patient with CDK4/6i (either ribociclib or palbociclib) combination therapy, fulvestrant, paclitaxel and capecitabine were estimated to be 1.4, 1.0, 0.9 and 0.7, respectively. None of the treatment arms are cost effective at current prices and reimbursement rates at a threshold of 1-time the per capita GDP of India. However, a 78% reduction in the current market price or a 72% reduction in the reimbursement rate of fulvestrant in the government-funded insurance program will make it a cost-effective treatment option for HR+, HER2- MBC patients in India.. CDK4/6i (ribociclib and palbociclib) therapy is not a cost-effective treatment option for MBC patients. A 72% reduction in the reimbursement rate for fulvestrant monotherapy will make it a cost-effective treatment option in the Indian context.

Topics: Aminopyridines; Antineoplastic Combined Chemotherapy Protocols; Breast Neoplasms; Capecitabine; Cost-Benefit Analysis; Female; Fulvestrant; Humans; Paclitaxel; Piperazines; Postmenopause; Purines; Pyridines

Despite significant improvement in therapeutic development in the past decades, breast cancer remains a formidable cause of death for women worldwide. The hormone positive subtype (HR(+)) (also known as luminal type) is the most prevalant category of breast cancer, comprising ~70% of patients. The clinical success of the three CDK4/6 inhibitors palbociclib, ribociclib, and abemaciclib has revolutionized the treatment of choice for metastatic HR(+) breast cancer. Accumulating evidence demonstrate that the properties of CDK4/6 inhibitors extend beyond inhibition of the cell cycle, including modulation of immune function, sensitizing PI3K inhibitors, metabolism reprogramming, kinome rewiring, modulation of the proteosome, and many others. The ubiquitin-proteasome pathway (UPP) is a crucial cellular proteolytic system that maintains the homeostasis and turnover of proteins.. We performed transcriptional profiling of the HR(+) breast cancer cell lines MCF7 and T47D treated with Palbociclib. Differential expressed genes were analyzed for novel pathways enriched. The results were further validated with biochemical assays and with real world clinical database cohorts.. We uncovered a novel mechanism that demonstrate the CDK4/6 inhibitors suppress the expression of three ubiquitin conjugating enzymes UBE2C, UBE2S, UBE2T. Further validation in the HR(+) cell lines show that Palbociclib and ribociclib decrease UBE2C at both the mRNA and protein level, but this phenomenon was not shared with abemaciclib. These three E2 enzymes modulate several E3 ubiquitin ligases, including the APC/C complex which plays a role in G1/S progression. We further demonstrate the UBE2C/UBE2T expression levels are associated with breast cancer survival, and HR(+) breast cancer cells demonstrate dependence on the UBE2C.. Our study suggests a novel link between CDK4/6 inhibitor and UPP pathway, adding to the potential mechanisms of their clinical efficacy in cancer.

Topics: Aminopyridines; Benzimidazoles; Breast Neoplasms; Cyclin-Dependent Kinase 4; Cyclin-Dependent Kinase 6; Female; Hormones; Humans; Phosphatidylinositol 3-Kinases; Proteasome Endopeptidase Complex; Protein Kinase Inhibitors; Purines; RNA, Messenger; Ubiquitin-Conjugating Enzymes; Ubiquitins

Ribociclib plus an aromatase inhibitor and ovarian function suppression is the preferred first-line option for pre-/perimenopausal women with hormone receptor-positive/human epidermal growth factor receptor-2-negative advanced or metastatic breast cancer. We opened an italian managed access program (MAP) that permitted access to ribociclib to selected patients and allowed to collect informative results on the clinical impact of the therapy. The MAP (April 2018-May 2020) included 64 premenopausal patients, with characteristics similar to those of the MONALEESA-7 trial. Of 57 patients with a known response, 48 (84.2%) achieved a clinical benefit (i.e., complete response, N = 7 (12.3%); partial response, N = 17 (29.8%); stable disease, N = 24 (42.1%)), while 9 (15.8%) experienced tumor progression. Some patients (N = 15-23.4%) needed ribociclib dose reduction because of adverse events. Thereafter, the treatment was well tolerated, and no new safety signals emerged. Our study is the first reported Italian real-world evidence of ribociclib effectiveness in premenopausal HR+/HER2- advanced breast cancer patients. Response and clinical benefit rates were particularly encouraging compared with those of the ribociclib group of MONALEESA-7. Our work confirms that ribociclib in combination with endocrine therapy is highly effective in the treatment of premenopausal HR+/HER2- advanced breast cancer patients with an expected safety profile.

Topics: Aminopyridines; Antineoplastic Combined Chemotherapy Protocols; Aromatase Inhibitors; Breast Neoplasms; Female; Gonadotropin-Releasing Hormone; Humans; Purines; Receptor, ErbB-2; Receptors, Estrogen

International guidelines recommend combining a CDK4/6 inhibitor and endocrine therapy (ET) as first line treatment for hormone receptor (HR) positive, HER2 negative metastatic breast cancer (MBC). Results from MONALEESA-2 demonstrate superior progression free survival (PFS) and overall survival (OS) with ribociclib (CDK4/6 inhibitor) and ET compared to ET alone. Real world outcomes have yet to be reported.. KARMA is a non-interventional registry of Australian patients receiving first-line treatment with ribociclib and aromatase inhibitor (AI), obtained via a Medicine Access Program (MAP) for HR+, HER2- MBC. Outcomes were compared with the ribociclib/letrozole cohort in MONALEESA-2.. Data from 160 patients at 17 sites was analysed. Median follow-up is 36.5 months. Compared to MONALEESA-2, patients were numerically younger (54.3 vs. 62 years), with higher rates of bone-only metastases (31% vs. 21%). A total of 63 of 160 (39%) patients remain on treatment. A total of 56% of patients had at least 1 dose reduction, with neutropenia (68%) and abnormal liver enzymes (17%) the most common reasons. A total of 17 of 160 (11%) discontinued treatment due to toxicity, with no treatment related deaths. Median PFS was not reached (95% CI 29.9- NR), with PFS at 12 months and 18 months being 76% and 67% respectively versus 25.3 months, 73% and 63% in MONALEESA-2.. The ribociclib and AI combination was well tolerated in this real-world setting. The KARMA registry cohort achieved a superior PFS (>36.5 months) to MONALEESA-2, potentially due to more favourable baseline disease characteristics. Less frequent assessment scheduling in this non trial setting may also contribute.

Topics: Antineoplastic Combined Chemotherapy Protocols; Aromatase Inhibitors; Australia; Breast Neoplasms; Female; Humans; Letrozole; Receptor, ErbB-2; Receptors, Estrogen

Gastric pH changes by proton-pump-inhibitors (PPIs) were found to affect progression-free survival (PFS) in metastatic breast cancer (mBC) patients treated with palbociclib. The current study was aimed at investigating whether the same effect could occur in patients treated with ribociclib.. Patients with hormone-positive/HER-2-negative mBC candidates for first-line treatment with ribociclib were enrolled in this retrospective-cohort study. Patients were classified as "no concomitant PPIs" or "concomitant PPIs"; PPI administration covered the entire or not less than 2/3 of treatment with ribociclib. All clinical interventions were made according to clinical practice.. A total of 128 patients were consecutively enrolled in the study; 78 belonged to the "no concomitant PPIs" group and 50 to the "concomitant PPIs" group. One hundred and six patients were endocrine-sensitive and received ribociclib and letrozole, while 22 were endocrine-resistant and were treated with ribociclib and fulvestrant. The most prescribed PPI was lansoprazole. According to PFS, patients taking PPIs had a PFS almost superimposable to those assuming ribociclib and endocrine therapy alone (35.3 vs. 49.2 months, p = 0.594). No difference in PFS was observed in estrogen-sensitive or estrogen-resistant mBC in the presence or absence of concomitant PPI treatment (p = 0.852). No correlation with adverse events was found including grade>2 hematological toxicities.. The present study supports the hypothesis that the concomitant use of PPIs does not compromise the efficacy of ribociclib in a real-life setting.

Topics: Aminopyridines; Antineoplastic Combined Chemotherapy Protocols; Breast Neoplasms; Cohort Studies; Estrogens; Female; Humans; Proton Pump Inhibitors; Retrospective Studies

To evaluate the effect of ribociclib versus endocrine therapy on productivity losses due to advanced breast cancer.. Productivity data from the MONALEESA-7 trial, obtained from the results of the application of the Work Productivity and Activity Impairment (WPAI) questionnaire on progression-free survival state (43-month follow-up), were extrapolated to the 10,936 Brazilian prevalent cases of premenopausal women with hormone receptor positive/human epidermal growth factor receptor 2 negative (HR+/HER2-) breast cancer. Productivity loss was determined by quantifying the economic costs of workforce dropout over time in both treatment arms and by discounting the economic costs of absenteeism and presenteeism from workforce retention. A human capital approach was used.. Net productivity gains in the ribociclib arm were estimated at USD 4,285,525.00, representing 316,609 added work hours over 43 months and a mean of 2,009 added work weeks per year.. The phase III MONALEESA-7 trial productivity results applied to the Brazilian premenopausal prevalent cases of hormone receptor positive/human epidermal growth factor receptor 2 negative (HR+/HER2-) breast cancer showed that treatment with ribociclib + endocrine therapy improves workforce participation compared with endocrine therapy alone in premenopausal women with hormone receptor positive/human epidermal growth factor receptor 2 negative (HR+/HER2-) metastatic breast cancer, with potential economic gains for the Brazilian society.

Topics: Antineoplastic Combined Chemotherapy Protocols; Brazil; Breast Neoplasms; Female; Humans; Receptors, Estrogen

Analysis of cell-free circulating tumor DNA obtained by liquid biopsy is a non-invasive approach that may provide clinically actionable information when conventional tissue biopsy is inaccessible or infeasible. Here, we followed a patient with hormone receptor-positive and human epidermal growth factor receptor (HER) 2-negative breast cancer who developed bone metastases seven years after mastectomy. We analyzed circulating cell-free DNA (cfDNA) extracted from plasma using high-depth massively parallel sequencing targeting 468 cancer-associated genes, and we identified a clonal hotspot missense mutation in the

Topics: Aromatase Inhibitors; Biomarkers, Tumor; Breast Neoplasms; Circulating Tumor DNA; Female; Genomics; Humans; Letrozole; Mastectomy; Mutation

Topics: Antineoplastic Combined Chemotherapy Protocols; Breast Neoplasms; Cost-Benefit Analysis; Female; Humans; Pyridines

Breast cancer is the most frequently diagnosed cancer in women worldwide. Ribociclib is now frequently used in the treatment of metastatic hormone-positive and human epidermal growth factor receptor 2 (HER 2)-negative breast cancer.. A 54-year-old woman with breast cancer presented at a clinic in November 2017 with multiple lung and bone metastases. After receiving multiple lines of treatment due to disease progression, ribociclib and fulvestrant were initiated. Grade 4 toxicity was observed due to ribociclib during follow-up, and ribociclib was discontinued permanently.. Although there are reported cases showing improvement in liver enzymes after ribociclib discontinuation, in our case, no recovery from hepatotoxicity was noticed. The treatment was changed to another hormonal pathway therapy option, exemestane. To the best of our knowledge, this is the first case in the literature reporting this rare side effect of ribociclib, which is a liver biopsy-proven fulminant hepatitis.

Topics: Aminopyridines; Antineoplastic Combined Chemotherapy Protocols; Biopsy; Breast Neoplasms; Female; Humans; Massive Hepatic Necrosis; Middle Aged; Purines

CDK 4/6 inhibitors, in combination with endocrine therapy, are the standard of care for patients with endocrinesensitive advanced breast cancer. This class of drug, however, is associated with QT prolongation, which serves as a surrogate marker for Torsades de Pointes (TdP), a cause of life-threatening ventricular arrhythmias and sudden cardiac death. The ICH E14 guidance document uses the Bazett formula for reporting of cardio-dynamic and safety ECG data in clinical trials. While there is substantial familiarity with the Bazett (QTcB) formula (QT/(RR) 1/2), the Fridericia (QTcF) formula (QT/(RR) 1/3 ) is preferred in the cancer population as it is often more accurate at heart rate extreme. Accordingly, the Fridericia formula is currently the standard adopted by the FDA when submitting QT data for review. At the King Faisal Specialist Hospital and Research Center, a total of 82 patients with advanced breast cancer, had a baseline ECG on day 1 before the initiation of ribociclib based therapy. Of the enrolled 82 patients, 19 (23%) were initially excluded from receiving ribociclib based due to a prolonged QTc >450ms, however, when the QTc-interval was manually measured and recalculated using Fridericia and Framingham formulae using MDCalC (https://www.mdcalc.com),17 of 19 patients successfully received their treatment without any arrhythmogenic effects. Repeat ECG on day14, and day 1 of cycle 2 demonstrated that none of these patients had QTc exceeding 480 ms. Our data highlights the complexities of evaluating the QT interval in oncology patients and the utility of the Fridericia/Framingham formulae in this population. Given these findings, we recommend the adoption of the Fridericia or Framingham formulae for measurement of QTc in all cancer patients exposed to potentially QT-prolonging cancer therapy.

Topics: Breast Neoplasms; Electrocardiography; Female; Heart Rate; Humans; Long QT Syndrome

Topics: Anti-Bacterial Agents; Breast Neoplasms; Cell Line, Tumor; Cell Proliferation; Female; Humans; MCF-7 Cells; Quinolines; Receptor, Bradykinin B2

Topics: Aminopyridines; Antineoplastic Agents; Breast Neoplasms; Chromatography, Liquid; Dried Blood Spot Testing; Drug Monitoring; Female; Humans; Letrozole; Piperazines; Purines; Pyridines; Tandem Mass Spectrometry

In this open-label, multicenter, phase Ib study, 70 postmenopausal women with HR. The recommended phase II dose (RP2D) of ribociclib was confirmed to be 600 mg (3 weeks on, 1 week off) and 400 mg (continuous dosing) plus fulvestrant 500 mg. For the triple combination with buparlisib, the RP2D was ribociclib 400 mg plus buparlisib 30 mg plus fulvestrant 500 mg. Enrollment for the triple combinations was stopped due to unexpected toxicity. No RP2D was determined for the alpelisib combination. The safety profiles of the ribociclib plus fulvestrant combinations were consistent with those in previous studies. There was no marked difference in ribociclib exposure in the presence of triple-combination partners. The highest overall response rate was seen in the buparlisib triple combination (25.0%; 95% confidence interval, 9.8-46.7).. Ribociclib plus fulvestrant demonstrated safety in the treatment of patients with HR

Topics: Aminopyridines; Antineoplastic Combined Chemotherapy Protocols; Breast Neoplasms; Cyclin-Dependent Kinase 4; Female; Fulvestrant; Humans; Morpholines; Phosphatidylinositol 3-Kinases; Purines; Receptors, Estrogen; Thiazoles

CDK4/6 inhibitors have shown promising results for treating advanced breast cancer (ABC) and are routinely used in Singapore. In view of their high costs, it is important to assess their relative value compared to existing standards of care in the local setting.. This study evaluates the cost-effectiveness of adding ribociclib to goserelin and a nonsteroidal aromatase inhibitor or tamoxifen as initial therapy for premenopausal women with hormone receptor-positive (HR+), human epidermal growth factor receptor 2-negative (HER2-) ABC in Singapore.. A partitioned survival model with four health states (progression-free on first-line treatment, progression-free on second-line treatment, progressed disease, and death) was developed from a healthcare system perspective over a 10-year time horizon. Key clinical inputs were derived from the MONALEESA-7 trial, and survival curves were extrapolated beyond the trial period. Health state utilities were derived from the literature and direct medical costs were obtained from local public healthcare institutions. A discount rate of 3% was applied to both costs and outcomes. One-way deterministic and probabilistic sensitivity analyses were conducted to explore uncertainties.. The base-case analysis resulted in an incremental cost-effectiveness ratio (ICER) of SGD197, 667 per quality-adjusted life-year. Sensitivity analyses showed that the ICER was sensitive to the survival parametric distribution, ribociclib price, time horizon, and utility weights used. Even when these were varied, ICERs remained high and not cost-effective in the local context.. At its current price, adding ribociclib to endocrine therapy is unlikely to be cost-effective in Singapore for HR+, HER2- ABC. Results from this study are useful to inform future funding decisions for CDK4/6 inhibitors alongside other factors including clinical effectiveness, safety, and budget impact considerations.

Topics: Aminopyridines; Antineoplastic Combined Chemotherapy Protocols; Aromatase Inhibitors; Breast Neoplasms; Chemotherapy, Adjuvant; Clinical Trials, Phase III as Topic; Drug Costs; Female; Follow-Up Studies; Goserelin; Humans; Kaplan-Meier Estimate; Mastectomy; Middle Aged; Multicenter Studies as Topic; Neoadjuvant Therapy; Premenopause; Progression-Free Survival; Purines; Quality-Adjusted Life Years; Randomized Controlled Trials as Topic; Singapore; Survival Rate; Treatment Outcome

Background Palbociclib and ribociclib are novel oral agents in hormone receptor-positive metastatic breast cancer. Neutropenia is a common adverse event associated with these treatments and its clinical management often requires regimen changes, such as cycle delays and dose adjustments. Objective To provide a real-world experience of the effectiveness and toxicities associated with these drugs and to evaluate the impact of regimen changes in disease progression. Setting This study was performed at Hospital Universitario La Paz, in Spain. Methods Observational, retrospective study which included hormone receptor-positive metastatic breast cancer patients who initiated treatment with palbociclib or ribociclib between March 1st, 2018 and March 1st, 2019. Main outcome measure The primary effectiveness variable was progression-free survival. Safety evaluation was performed to determine neutropenia-incidence and severity, as well as its clinical management, including dose adjustments and treatment interruptions. Correlations between these regimen changes and effectiveness were also evaluated. Results Sixty-one patients were included, 33 treated with palbociclib and 28 with ribociclib. Palbociclib was mainly used as second line of treatment in the metastatic setting (81.8%) and ribociclib as first line (67.9%). The median progression-free survival was 12.76 months (95% CI 7.5 to not estimable) in palbociclib and not reached in ribociclib. After 12 months, the progression-free survival rate was 51.5% (95% CI 34-69) in palbociclib and 78.6% (95% CI 63-94.1) in ribociclib. Neutropenia was the most common adverse event with an incidence rate of 87.9% in palbociclib and 82.1% in ribociclib. Cycle delays were needed in more than half of the patients treated with palbociclib and ribociclib (63.6% and 64.3%). Dose adjustments were seen in 42.4% and 53.6% of the patients receiving palbociclib and ribociclib, respectively. Regimen changes did not involve statistically significant differences in 12-month PFS rates in the cohort investigated. Conclusion Palbociclib and ribociclib outcomes are comparable to those reached in the phase III trials, PALOMA-3 and MONALEESA-2, respectively, and cannot be compared as they were used in different treatment settings. The toxicity profile is favourable, being neutropenia the most common adverse event, easily managed with regimen changes. Further studies are needed to confirm the observed tendency of no detrimental impact on effectiven

Topics: Aminopyridines; Antineoplastic Combined Chemotherapy Protocols; Breast Neoplasms; Female; Humans; Piperazines; Purines; Pyridines; Retrospective Studies

Topics: Aminopyridines; Breast Neoplasms; Chemical and Drug Induced Liver Injury; Female; Humans; Purines

Topics: Aminopyridines; Breast Neoplasms; Female; Humans; Neoplasms; Prognosis; Purines

Lay abstract Palbociclib (PAL), ribociclib (RIB) and abemaciclib (ABM) are used with fulvestrant to treat hormone receptor-positive, HER2-negative advanced breast cancer. This study aims to use data from clinical trials to compare how long patients live after starting treatment with PAL versus RIB and ABM. Since patients who enroll in different trials may have different characteristics, it is important to adjust for these differences for a more accurate comparison. Adjusting for these differences showed that patients with hormone receptor-positive, HER2-negative advanced breast cancer treated with PAL lived for a similar length of time compared with those treated with RIB or ABM.

Topics: Aminopyridines; Antineoplastic Combined Chemotherapy Protocols; Benzimidazoles; Breast Neoplasms; Humans; Piperazines; Purines; Pyridines; Receptor, ErbB-2

Treatment for estrogen receptor positive (ER+), human epidermal receptor 2 negative (HER2-) metastatic breast cancer (MBC) has improved with the approval of CDK 4/6 inhibitors. Clinical trials with the CDK4/6 inhibitor ribociclib, suggest that 35% to 57.5% of the patients require a dose reduction during ribociclib treatment. Data on the possible consequences of dose reduction concerning efficacy is needed.. A retrospective cohort study on patients with ER+ HER2- MBC from three Danish oncology departments. Data on tolerability and progression-free survival were collected from electronic health records.. One hundred and twenty-eight patients with ER+ HER2- MBC who initiated ribociclib treatment between 1st of January 2018 to 31st of March 2020 were included in our analysis. Of these patients, 48.4% required one or more dose reductions. Overall median PFS was 19.2 months (CI-95% 14.3-NR). Patients with one or more dose reductions did not have decreased median PFS (19.2 months, CI-95% 14.3-NR compared to 12.2 months, CI-95% 7.3-NR, p = 0.078). Frequency of adverse events were as previously reported, with grade III and IV neutropenia occurring in 45.3% and 7% of patients, respectively. Patients treated with fulvestrant versus an aromatase inhibitor and patients with lymph node involvement at baseline had lower odds of requiring a dose reduction (OR. Our results indicate that dose reduction of ribociclib is safe and do not compromise the efficacy of the treatment. Furthermore, the study supports translation of results from the MONALEESA trials to patients treated in real-world clinical settings.

Topics: Aminopyridines; Antineoplastic Combined Chemotherapy Protocols; Breast Neoplasms; Female; Humans; Purines; Receptor, ErbB-2; Receptors, Estrogen; Retrospective Studies

Among females, breast cancer is the most common type of cancer. Hormon receptor positive (HR+) subtype constitutes 75% of the diagnosed breast cancers. Combination of the cyclin D-cyclin-dependent kinase 4/6 (CDK4/6) inhibitor and endocrine therapy significantly improves overall survival and progression-free survival. Ribociclib is an oral CDK 4/6 inhibitor and some adverse effects are identified. According to MONALEESA 2-3-7 studies, no adverse effect (AE) were reported due to grade 3 or 4 acute kidney injury (AKI) that caused treatment discontinuation.. We report a ribociclib-induced grade 3 AKI in an elderly woman who was treated for metastatic breast cancer. During first cycle of therapy, she was admitted to the oncology clinic with diagnosis of AKI.. According to MONALEESA 2-3-7 studies; no AE were reported due to grade 3 or 4 AKI. Despite these studies, the FDA reported that 20% of patients with ribociclib + letrozole combination therapy may have any stage elevation of creatinine. Ribociclib induced creatinine elevations are generally mild (grade 1-2) and can be managed by dose reduction or close monitoring of creatinine levels. We report the first case of grade 3 AKI that caused treatment discontinuation following administration of ribociclib.

Topics: Acute Kidney Injury; Aged; Aminopyridines; Antineoplastic Combined Chemotherapy Protocols; Breast Neoplasms; Female; Humans; Letrozole; Neoplasm Recurrence, Local; Purines; Receptors, Estrogen

Topics: Aged; Aminopyridines; Antineoplastic Agents; Breast Neoplasms; Drug-Related Side Effects and Adverse Reactions; Exanthema; Female; Humans; Piperazines; Purines; Pyridines

The MONALEESA-7 trial demonstrated the efficacy and safety of ribociclib plus a nonsteroidal aromatase inhibitor (NSAI) [with goserelin] for pre-/perimenopausal women with hormone receptor-positive and human epidermal growth factor receptor 2-negative advanced breast cancer. This analysis evaluated the cost effectiveness of ribociclib plus NSAI vs NSAI monotherapy and tamoxifen monotherapy from the perspective of the Canadian healthcare system.. The incremental cost-effectiveness ratio expressed as incremental costs per quality-adjusted life-year (QALY) gained for ribociclib plus an NSAI vs an NSAI and vs tamoxifen was estimated using a semi-Markov cohort model developed in Microsoft Excel with a 15-year time horizon and states for progression-free survival, post-progression survival, and dead. Survival distributions for progression-free survival, post-progression survival, and time to discontinuation as well as health-state utilities were estimated using data from MONALEESA-7. Direct costs of advanced breast cancer treatment were based on Canadian-specific values from published sources. Costs ($CAN 2019) and QALYs were discounted at 1.5% annually.. Ribociclib plus an NSAI was estimated to yield gains of 1.42 life-years and 1.17 QALYs vs an NSAI, and 2.61 life-years and 2.12 QALYs vs tamoxifen, at incremental costs of $209,701 and $220,836, respectively. In probabilistic analyses, the incremental cost-effectiveness ratio for ribociclib plus an NSAI was estimated to be $178,872 per QALY gained vs an NSAI and $104,400 per QALY gained vs tamoxifen. Results of deterministic analyses were similar (incremental cost-effectiveness ratios of $177,245 and $103,316 vs NSAI and tamoxifen, respectively). Results were sensitive to parametric distributions used for projecting progression-free survival and the time horizon.. At its current list price, ribociclib used in combination with NSAI is likely to be co-effective relative to an NSAI alone or tamoxifen alone if the willingness-to-pay threshold is less than approximately $178,000 per QALY. These results have informed deliberations regarding reimbursement and access to this treatment in Canada and may be useful for decision makers in other settings.

Topics: Aminopyridines; Antineoplastic Combined Chemotherapy Protocols; Aromatase Inhibitors; Breast Neoplasms; Canada; Cost-Benefit Analysis; Delivery of Health Care; Female; Humans; Perimenopause; Purines; Quality-Adjusted Life Years

The MONALEESA-3 trial demonstrated the efficacy and safety of ribociclib plus fulvestrant versus placebo plus fulvestrant for patients with hormone receptor-positive and human epidermal growth factor receptor 2-negative (HR+/HER2-) advanced breast cancer (ABC). This analysis evaluated the cost effectiveness of ribociclib plus fulvestrant versus fulvestrant in patients with HR+/HER2- ABC from a Canadian healthcare payer perspective.. The incremental cost-effectiveness ratio (ICER), expressed as incremental costs per quality-adjusted life-year (QALY) gained for ribociclib plus fulvestrant versus fulvestrant, was estimated using a semi-Markov cohort model developed in Microsoft Excel, with states for progression-free, post-progression, and dead. A 15-year time horizon was used. Survival distributions for progression-free survival (PFS), post-progression survival (PPS), and time to discontinuation (TTD) were based on parametric survival distributions fit to data from MONALEESA-3. Health-state utilities were estimated using EQ-5D index values collected in MONALEESA-3. Direct costs of ABC treatment (medication and administration costs, follow-up and monitoring, adverse events, subsequent treatments) were based on Canadian-specific values from published sources. Costs (2019 CAN$) and QALYs were discounted at 1.5% annually.. In the base case, ribociclib plus fulvestrant was estimated to result in gains of 1.19 life-years and 0.96 QALYs versus fulvestrant, at an incremental cost of $151,371. The ICER of ribociclib plus fulvestrant versus fulvestrant was $157,343 per QALY gained based on the mean of probabilistic analyses. Results were sensitive to parametric distributions used for projecting long-term TTD, PFS, and PPS.. For patients with HR+/HER2- ABC, ribociclib plus fulvestrant is projected to result in substantial gains in QALYs compared with fulvestrant. At its current list price, ribociclib used in combination with fulvestrant is likely to be cost effective in these patients at a threshold ICER of $157,343. These results may be useful in deliberations regarding reimbursement and access to this treatment.

Topics: Aminopyridines; Antineoplastic Combined Chemotherapy Protocols; Breast Neoplasms; Canada; Cost-Benefit Analysis; Delivery of Health Care; Female; Fulvestrant; Humans; Postmenopause; Purines; Receptor, ErbB-2

There is scant data from India on efficacy and safety of palbociclib and ribociclib in routine clinical practice.. This retrospective, observational, single institution study included patients with estrogen and/or progesterone receptor positive and human epidermal growth factor receptor 2 (HER2) negative metastatic breast cancers, who received palbociclib or ribociclib with any partner endocrine therapy in any line of treatment between January 2016 and June 2019. Data were analyzed for progression-free survival (PFS), overall survival (OS) and toxicity.. The study included 101 female patients with median age of 57 (IQR 48-62) years, of whom 80 (79.2%) were postmenopausal, 79 (78.2%) received palbociclib or ribociclib in second- or later-line treatment, 59 (58.4%) received fulvestrant and 41 (40.6%) received an aromatase inhibitor. In first-line treatment, at a median follow-up of 21.7 (0.5-41.9) months, median PFS and OS were 21.1 (95%CI 16.36-not estimable) months and not reached, respectively. In second- or later-line setting, at a median follow-up of 17.2 (0.5-43.7) months, median PFS and OS were 5.98 (95%CI 4.96-7.89) months and 20.2 (95%CI 14.1-not estimable) months, respectively. Grade 3-4 neutropenia and febrile neutropenia were seen in 45 (45.0%) and 9 (9.0%) patients, respectively while dose reduction was required in 32 (31.7%) patients. In multivariable Cox regression analysis, first-line setting (HR 0.49, 95%CI 0.25-0.97, p = 0.043) and ECOG performance status 1 (HR 0.43, 95%CI 0.20-0.91, p = 0.028) were significantly associated with PFS while only ECOG PS 1 was significantly associated (HR 0.04, 95%CI 0.008-0.206, p = 0.000) with OS.. Palbociclib and ribociclib, when used in routine clinical practice in first or subsequent lines of treatment, resulted in efficacy and toxicity outcomes in concordance with those expected from pivotal trials.

Topics: Aged; Aminopyridines; Breast Neoplasms; Databases, Factual; Disease-Free Survival; Female; Follow-Up Studies; Humans; Middle Aged; Neoplasm Metastasis; Piperazines; Purines; Pyridines; Receptor, ErbB-2; Receptors, Estrogen; Receptors, Progesterone; Retrospective Studies; Survival Rate

Data are sparse for oral selective estrogen receptor (ER) degraders (SERD) in cancer treatment. The investigational oral SERD LSZ102 was assessed in monotherapy and combination use in a phase I study.. The most common AEs were gastrointestinal. Treatment-related serious AEs occurred in 10% of participants (19/198), mostly in arm C [10/43 (23%)]. DLTs occurred in: arm A, 5% (4/77); arm B, 3% (2/78); and arm C, 19% (8/43). LSZ102 exposure was slightly greater than dose proportional. On-treatment biopsy ER reductions were observed, with a trend toward an LSZ102 dose response. Objective response rates (95% confidence interval) were: arm A, 1.3% (0.0-7.0); arm B, 16.9% (9.3-27.1); and arm C, 7.0% (1.5-19.1), and clinical benefit rates 7.8% (2.9-16.2), 35.1% (24.5-46.8), and 20.9% (10.0-36.0), respectively.. LSZ102 was well tolerated alone and with ribociclib and had a manageable safety profile with alpelisib. Preliminary clinical activity was observed in combination use.

Topics: Adult; Aminopyridines; Antineoplastic Combined Chemotherapy Protocols; Breast Neoplasms; Female; Humans; Purines; Receptors, Estrogen; Thiazoles; Thiophenes

Topics: Aminopyridines; Breast Neoplasms; Female; Humans; Purines; Stevens-Johnson Syndrome

A 59-year-old woman presented with a bone-only metastatic luminal breast cancer. She received first-line treatment with aromatase inhibitors associated with a cyclin-dependent kinase (CDK) 4/6 inhibitor, ribociclib. She developed Grade 3 elevated transaminases leading us to interrupt ribociclib permanently. Specific toxicity of the CDK 4/6 inhibitor ribociclib was retained. Once transaminase levels normalized, the patient initiated another CDK4/6 inhibitor, palbociclib, using an escalating dose without reappearance of hepatic injury. This case suggests the possibility of rechallenge after hepatic toxicity with a different CDK 4/6 inhibitor using dose escalation and careful monitoring.

Topics: Alanine Transaminase; Aminopyridines; Aromatase Inhibitors; Aspartate Aminotransferases; Bone Neoplasms; Breast Neoplasms; Carcinoma, Lobular; Chemical and Drug Induced Liver Injury; Cyclin-Dependent Kinase 4; Cyclin-Dependent Kinase 6; Drug Substitution; Drug Therapy, Combination; Female; Humans; Letrozole; Middle Aged; Piperazines; Protein Kinase Inhibitors; Purines; Pyridines

CDK4/6 inhibitors in association with aromatase inhibitors have led to a paradigm shift in the management of metastatic positive hormone-receptors breast cancer. Liver toxicity is common with these agents, but no data are reported on the sequential use of these CDK4/6 inhibitors in case of confirmed efficacy and intolerable toxicity. In this article, we report the successful use of Palbociclib in a metastatic positive hormone-receptors breast cancer patient after initial response to Ribociclib, which was interrupted for grade 4 liver toxicity.

Topics: Aminopyridines; Antineoplastic Combined Chemotherapy Protocols; Breast Neoplasms; Chemical and Drug Induced Liver Injury; Female; Humans; Letrozole; Liver; Middle Aged; Piperazines; Protein Kinase Inhibitors; Purines; Pyridines; Receptors, Estrogen; Receptors, Progesterone; Zoledronic Acid

Topics: Aminopyridines; Breast Neoplasms; Female; Humans; Letrozole; Postmenopause; Purines; Receptor, ErbB-2; Receptors, Progesterone

Topics: Aminopyridines; Breast Neoplasms; Humans; Perimenopause; Purines

Topics: Aminopyridines; Betacoronavirus; Breast Neoplasms; Coronavirus Infections; COVID-19; Humans; Pandemics; Pneumonia, Viral; Purines; SARS-CoV-2; Triage

Topics: Aminopyridines; Betacoronavirus; Breast Neoplasms; Coronavirus Infections; COVID-19; Humans; Pandemics; Pneumonia, Viral; Purines; SARS-CoV-2; Triage

Topics: Aminopyridines; Breast Neoplasms; Fulvestrant; Humans; Purines

Topics: Aminopyridines; Breast Neoplasms; Fulvestrant; Humans; Purines

The ongoing, Phase Ib MONALEESASIA study is evaluating the efficacy and safety of ribociclib plus endocrine therapy in Asian patients with hormone receptor-positive, human epidermal growth factor receptor 2-negative advanced breast cancer. Eligible patients from Japan, Hong Kong, and Singapore were enrolled in this 2-phase study consisting of a dose-escalation phase to determine the maximum-tolerated dose and the recommended Phase II dose of ribociclib plus letrozole, and a dose-expansion phase to evaluate safety and tolerability of ribociclib plus letrozole, fulvestrant, or tamoxifen. An exploratory biomarker analysis evaluating expression of target genes was also conducted. In the dose-escalation phase, the maximum-tolerated/recommended Phase II doses of ribociclib were lower in Japanese patients (300 mg) than in Asian non-Japanese patients (600 mg). Ribociclib plus endocrine therapy at the recommended Phase II dose had a manageable safety profile, with neutropenia and elevated liver transaminases being the most common adverse events leading to dose modifications or discontinuations, and it demonstrated evidence of clinical activity in both Japanese and Asian non-Japanese patients. Preliminary efficacy in Asian populations is similar to that observed in White populations studied in previous ribociclib (MONALEESA) trials. Biomarker analysis demonstrated suppression of pharmacodynamic biomarker gene expression, indicating inhibition of target genes by ribociclib combined with endocrine therapy. Results from the ongoing study support the use of ribociclib in combination with letrozole in Asian non-Japanese patients at the same dose (600 mg) as White patients. In Japanese patients, a lower dose of ribociclib (300 mg) should be considered. Clinicaltrials.gov: NCT02333370.

Topics: Aged; Aged, 80 and over; Aminopyridines; Antineoplastic Agents, Hormonal; Antineoplastic Combined Chemotherapy Protocols; Asian People; Biomarkers; Breast Neoplasms; Cyclin-Dependent Kinase 4; Cyclin-Dependent Kinase 6; Female; Humans; Japan; Middle Aged; Neoplasm Grading; Neoplasm Metastasis; Neoplasm Staging; Protein Kinase Inhibitors; Purines; Treatment Outcome

The cyclin-dependent kinase 4/6 inhibitors (CDK4/6i) represent the standard treatment for hormone receptor-positive, human epidermal growth factor receptor 2-negative metastatic breast cancer. Data about the balance between efficacy and toxicity of combined palliative radiotherapy (RT) and CDK4/6 inhibition are lacking.. We undertook a review of 46 patients with metastatic breast cancer on systemic treatment with CDK4/6i who underwent 62 metastases-directed RT. Clinical, laboratory, and RT treatment planning data were collected. Statistical analyses included Student t test, paired sample t test, and logistic regression modeling.. Thirty patients (65.2%) received palbociclib, 15 (32.6%) received ribociclib, and one patient received abemaciclib (2.2%). Median total prescribed RT dose was 20 Gy (range, 8-63 Gy). Sites of RT were bone (n = 50; 80.7%), visceral (n = 7; 11.3%), or brain metastases (n = 3; 4.8%), as well as primary tumor of the breast (n = 2; 3.2%). Overall, the rates of grade 3 or higher adverse events (AEs) were 6.5%, 4.3%, 15.2%, and 23.9% before the start of RT, during RT, 2 and 6 weeks after RT completion, respectively. We found no correlation between dose distribution to organs at risk and the development of AEs. The local control rates for the entire cohort were 98% at 6 months and 90% at 12 months. Overall, pain relief (complete or partial) was experienced by 80% (24/30) of patients who initially reported pain at the treated metastatic site.. We observed a modest increase in the rates of grade 3 or higher AEs after combined RT and CDK4/6i, with maintained efficacy of concomitant RT.

Topics: Adult; Aged; Aminopyridines; Benzimidazoles; Breast Neoplasms; Cancer Pain; Chemoradiotherapy; Cyclin-Dependent Kinase 4; Cyclin-Dependent Kinase 6; Female; Humans; Middle Aged; Molecular Targeted Therapy; Neoplasm Staging; Organs at Risk; Pain Measurement; Palliative Care; Piperazines; Protein Kinase Inhibitors; Purines; Pyridines; Radiotherapy Dosage; Treatment Outcome

Although metastatic breast cancer can be fatal, a series of randomized double-blind placebo-controlled phase 3 trials (MONALEESA studies) have shown that ribociclib is an effective anticancer drug for the treatment of advanced breast cancer with bones, liver, lungs, and brain as major metastatic sites. Here, we report the clinical case of a woman with peritoneal carcinomatosis secondary to HER2-negative estrogen receptor-positive breast cancer successfully treated with ribociclib and letrozole. After 9-month follow-up, total body computed tomography imaging showed resolution of hypodense areas surrounding the hepatic hilus with concomitant reduction in both bile duct dilatation and peritoneal effusion, and abdominal lymphadenopathy was excluded. Notably, therapy was well tolerated throughout the treatment with no side effects.

Topics: Aminopyridines; Antineoplastic Combined Chemotherapy Protocols; Breast Neoplasms; Female; Humans; Peritoneal Neoplasms; Purines; Receptor, ErbB-2; Receptors, Estrogen; Receptors, Progesterone

Cyclin dependent kinases 4/6 (CDK4/6) inhibitors gained an essential role in the treatment of metastatic breast cancer. Nevertheless, data regarding their use in combination with radiotherapy are still scarce. We performed a retrospective preliminary analysis of breast cancer patients treated at our Center with palliative radiation therapy and concurrent CDK4/6 inhibitors. Toxicities were measured according to CTCAE 4.0, local response according to RECIST 1.1 or PERCIST 1.0 and pain control using verbal numeric scale. 18 patients (32 treated sites) were identified; 50% received palbociclib, 33.3% ribociclib and 16.7% abemacliclib. Acute non-hematologic toxicity was fair, with the only exception of a patient who developed G3 ileitis. During 3 months following RT, 61.1% of patients developed G 3-4 neutropenia; nevertheless no patient required permanent suspension of treatment. Pain control was complete in 88.2% of patients three months after radiotherapy; 94.4% of patients achieved and maintained local control of disease. Radiotherapy concomitant to CDK4/6 inhibitors is feasible and characterized by a fair toxicity profile, with isolated episodes of high-grade reversible intestinal toxicity. Rate of G 3-4 neutropenia was comparable with that measured for CDK4/6 inhibitors alone. Promising results were reported in terms of pain relief and local control of disease.

Topics: Aminopyridines; Breast Neoplasms; Combined Modality Therapy; Cyclin-Dependent Kinase 4; Cyclin-Dependent Kinase 6; Female; Humans; Ileitis; Molecular Targeted Therapy; Neoplasm Metastasis; Neutropenia; Outcome Assessment, Health Care; Piperazines; Protein Kinase Inhibitors; Purines; Pyridines; Radiotherapy; Retrospective Studies

Cyclin-dependent kinase inhibitors (CDKIs) and endocrine therapy (ET) are the corner-stone of systemic therapy for patients with hormone-positive (HR+) HER2-negative metastatic breast cancer (MBC). However, limited data exist regarding rechallenge treatment strategies with CDKIs after limiting toxicity. In this report, we provide evidence of the safety and efficacy of sequential treatment with palbociclib or abemaciclib in 6 HR+/HER- MBC patients who experienced grade ≥3 ribociclib-induced hypertransaminasemia. Until results from large observational or randomized studies are communicated, empirical evidence may help make individualized decisions on CDKI rechallenge beyond ribociclib-induced unacceptable liver toxicity.

Topics: Aminopyridines; Antineoplastic Agents; Benzimidazoles; Breast Neoplasms; Chemical and Drug Induced Liver Injury; Cyclin-Dependent Kinase 4; Cyclin-Dependent Kinase 6; Drug Substitution; Female; Humans; Middle Aged; Piperazines; Protein Kinase Inhibitors; Purines; Pyridines; Receptors, Estrogen; Receptors, Progesterone; Retrospective Studies; Transaminases; Treatment Outcome

Topics: Aminopyridines; Breast Neoplasms; Humans; Purines

Topics: Aminopyridines; Breast Neoplasms; Humans; Purines

Combination ribociclib and aromatase inhibitors are currently the preferred treatment in Australia for newly diagnosed hormone receptor positive metastatic breast cancer in the absence of visceral crisis. In our case series of 32 patients, 28% experienced grade 1 elevations in creatinine, a toxicity that was under-recognised in large phase III studies. Creatinine rise appears to be due to a reversible inhibition of renal efflux transporters rather than an acute kidney injury in the majority of cases.

Topics: Aged; Aminopyridines; Antineoplastic Agents; Antineoplastic Combined Chemotherapy Protocols; Aromatase Inhibitors; Breast Neoplasms; Creatinine; Disease-Free Survival; Female; Humans; Male; Middle Aged; Neoplasm Metastasis; New South Wales; Purines; Receptor, ErbB-2; Retrospective Studies

The addition of ribociclib (RIB) to letrozole (LET) significantly increases progression free survival for patients with hormone-receptor (HR)-positive, human epidermal growth factor receptor 2 (HER2)-negative advanced breast cancer (ABC). We identified the range of drug costs for which RIB could be considered cost effective from a Chinese perspective.. A discrete event simulation model was developed to model the treatment sequences among patients with ABC. Life years (LYs), quality-adjusted LYs (QALYs) and lifetime costs were estimated. Costs were estimated for Chinese health care systems. Three times the per capita gross domestic product (GDP) of China 2016 ($24,360) and three times the per capita GDP of Beijing city 2016 ($53,384) were used as the willingness-to-pay threshold. Probabilistic sensitivity analyses were performed.. In the base case analysis, RIB + LET provided an incremental survival benefit of 0.631 LYs and 0.451 QALYs. When RIB costs less than $721 or $1170 per 4 weeks, there was a nearly 90% likelihood that the incremental cost-effectiveness ratio for RIB + LET would be less than $24,360 per QALY or $53,384 per QALY, respectively.. A value-based price for the cost of RIB is $732 or $1170 per 4 weeks for China and Beijing City, respectively. Our study is helpful to inform the multilateral drug price negotiations in China that may be upcoming for RIB.

Topics: Aminopyridines; Antineoplastic Combined Chemotherapy Protocols; Breast Neoplasms; China; Cost-Benefit Analysis; Drug Costs; Female; Humans; Letrozole; Progression-Free Survival; Purines; Quality-Adjusted Life Years; Receptors, Estrogen; Receptors, Progesterone

Three Cyclin Dependent Kinase 4/6 (CDK) inhibitors have been approved by the United Stated Food and Drug Administration for front line treatment of advanced hormone receptor positive breast cancer based on improvements in progression free survival against endocrine monotherapy. Two clinical trials have so far reported results on overall survival but both are negative. CDK inhibitors are usually tolerated well but they do add to inconvenience and cost - for example, grade III-IV neutropenia occur at a frequency of over 60% requiring frequent blood work at least during the initial months of treatment. These drugs cost over $ 13,500 for a 4-week cycle in the United States, and are responsible for billions of dollars annually in drug cost alone. Importantly, many women with metastatic breast cancer do well for a long time with endocrine therapy alone and CDK inhibitors do not have a predictive marker. Selective use of these agents in later lines may improve substantially the convenience and cost without compromise in overall outcome. However, with results demonstrating impressive improvements in PFS published in major medical journals coupled with patients' natural desire for "best available" options, the trend among oncologists is to prescribe these drugs as the default front-line treatment. In this commentary I caution readers against over interpretation of results from the CDK inhibitor trials, describe adverse consequences of routine front-line use, and explain why selective use in later line may yield a higher value.

Topics: Aminopyridines; Antineoplastic Agents, Hormonal; Benzimidazoles; Breast Neoplasms; Cost-Benefit Analysis; Cyclin-Dependent Kinase 4; Cyclin-Dependent Kinase 6; Drug Costs; Female; Humans; Neutropenia; Piperazines; Protein Kinase Inhibitors; Purines; Pyridines; Receptors, Estrogen; Receptors, Progesterone

Three CDK4/6 inhibitors, palbociclib (PAL), ribociclib (RIB), and abemaciclib, when combined with letrozole (LET), have been approved as first-line therapy for postmenopausal women with metastatic HR+, HER2- breast cancer. However, an economic evaluation of these newer therapies is currently lacking. The purpose of this article is to evaluate the cost-effectiveness of PAL or RIB for the treatment of advanced HR+, HER2- breast cancer in the United States.. A Markov simulation model was constructed using data from published clinical trials evaluating PAL and RIB. Three simulated treatment strategies included PAL + LET, RIB + LET, or LET alone. The main outcome measures were simulated progression-free survival (PFS), overall survival (OS), costs, quality-adjusted life-years (QALYs), and incremental cost-effectiveness ratios (ICERs).. Simulated median OS was 38.9 months for PAL + LET and 33.0 months for LET alone. Simulated median OS for RIB + LET was 43.3 months. Compared to LET alone, PAL + LET provided an additional 0.48 QALYs, on average, with an ICER of $634,000 per QALY gained; RIB + LET provided an additional 0.86 QALYs, on average, with an ICER of $440,000 per QALY gained. At current prices, neither PAL nor RIB was cost-effective, assuming a willingness-to-pay threshold of $100,000 per QALY gained. To reach such a cost-effectiveness threshold, PAL and RIB prices must decrease by approximately 70%.. Despite significant gains in progression-free survival over letrozole alone, the addition of palbociclib or ribociclib in the treatment of advanced HR+, HER2- breast cancer is not cost-effective in the United States given current drug prices.

Topics: Aminopyridines; Antineoplastic Combined Chemotherapy Protocols; Breast Neoplasms; Cost-Benefit Analysis; Female; Humans; Letrozole; Markov Chains; Models, Economic; Piperazines; Purines; Pyridines; Quality of Life; Receptor, ErbB-2; Survival Analysis; Treatment Outcome

Using an ORF kinome screen in MCF-7 cells treated with the CDK4/6 inhibitor ribociclib plus fulvestrant, we identified FGFR1 as a mechanism of drug resistance. FGFR1-amplified/ER+ breast cancer cells and MCF-7 cells transduced with FGFR1 were resistant to fulvestrant ± ribociclib or palbociclib. This resistance was abrogated by treatment with the FGFR tyrosine kinase inhibitor (TKI) lucitanib. Addition of the FGFR TKI erdafitinib to palbociclib/fulvestrant induced complete responses of FGFR1-amplified/ER+ patient-derived-xenografts. Next generation sequencing of circulating tumor DNA (ctDNA) in 34 patients after progression on CDK4/6 inhibitors identified FGFR1/2 amplification or activating mutations in 14/34 (41%) post-progression specimens. Finally, ctDNA from patients enrolled in MONALEESA-2, the registration trial of ribociclib, showed that patients with FGFR1 amplification exhibited a shorter progression-free survival compared to patients with wild type FGFR1. Thus, we propose breast cancers with FGFR pathway alterations should be considered for trials using combinations of ER, CDK4/6 and FGFR antagonists.

Topics: Aminopyridines; Animals; Antineoplastic Agents, Hormonal; Antineoplastic Combined Chemotherapy Protocols; Breast Neoplasms; Circulating Tumor DNA; Cyclin D1; Cyclin-Dependent Kinase 4; Cyclin-Dependent Kinase 6; Drug Resistance, Neoplasm; Female; Fulvestrant; High-Throughput Nucleotide Sequencing; Humans; MCF-7 Cells; Mice; Mutation; Naphthalenes; Piperazines; Progression-Free Survival; Proportional Hazards Models; Protein Kinase Inhibitors; Purines; Pyrazoles; Pyridines; Quinolines; Quinoxalines; Receptor, Fibroblast Growth Factor, Type 1; Receptor, Fibroblast Growth Factor, Type 2; Receptors, Estrogen; Signal Transduction; Xenograft Model Antitumor Assays

To evaluate the early toxicity of concurrent use of radiotherapy in association with CDK4/6 inhibitors (palbociclib or ribociclib) in patients with hormone-receptors positive metastatic breast cancer.. Records of patients with histologically proven metastatic or locally advanced breast cancer treated in our institution were reviewed. Patients who received radiotherapy and concurrent palbociclib or ribociclib were selected. Toxicity was assessed according to the National Cancer Institute Common Terminology Criteria for Adverse Events version 4.0 (NCI-CTCAE V4.0).. Sixteen consecutive metastatic breast cancer patients with 24 radiotherapy treatments were studied. Thirteen patients (81.3%) received palbociclib, 3 (18.7%) patients received ribociclib concurrently with RT (18 and 5 radiotherapy courses respectively). The majority of patients (68.7%) received palliative radiotherapy to the bones (median dose 30 Gy, range 8-36 Gy). Five patients (31.2%) were treated in oligo-metastatic or oligo-progressive sites of disease with higher doses (median dose = 50 Gy, range 39.6-60 Gy). The most common toxicity observed was hematological toxicity. Neutropenia was common (grade 2 = 12.5%; grade 3 = 25%, grade 4 = 6.3%); 60% of patients experiencing grade ≥ 3 neutropenia had already experienced neutropenia during previous cycles of palbociclib. One patient (6.3%) completed the RT course earlier (48 Gy of 50 Gy prescribed) and another patient (6.3%) suspended RT for 2 days.. concomitant treatment of CDK4/6 and radiotherapy seems well tolerated; high grade hematological toxicity is common, but did not change treatment course in the majority of patients. Previous toxicity should be carefully evaluated as it usually reoccurs.

Topics: Adult; Aged; Aged, 80 and over; Aminopyridines; Antineoplastic Agents; Breast Neoplasms; Chemoradiotherapy; ErbB Receptors; Female; Humans; Middle Aged; Neutropenia; Piperazines; Protein Kinase Inhibitors; Purines; Pyridines; Radiation Dosage; Treatment Outcome

Topics: Aminopyridines; Blood Platelet Disorders; Breast Neoplasms; Female; Humans; Middle Aged; Postmenopause; Protein Kinase Inhibitors; Purines

Topics: Aminopyridines; Breast; Breast Neoplasms; Humans; Purines

Discarding unused drugs after dose changes or discontinuation can significantly affect pharmacy budgets. This is especially concerning for expensive oncology agents. However, few economic studies account for drug wastage, providing an inaccurate estimate of a drug's actual economic cost, cost-effectiveness, and value.. To (a) compare the economic impact of drug wastage between ribociclib and palbociclib-clinically similar oral medications for metastatic breast cancer-using 3 approaches (Markov model, pharmacy acquisition cost model, and a retrospective claims analysis) and (b) compare the modeling results with a published estimate of drug wastage for palbociclib from a claims analysis.. A Markov model and a pharmacy acquisitions cost model were developed to evaluate the economic impact of dose reductions for ribociclib and palbociclib over a 1-year time period. Data inputs were pharmacy costs (RED BOOK wholesale acquisition cost) and proportion of patients experiencing dose reductions from either ribociclib randomized clinical trials (MONALEESA-2, -3, or -7) or real-world observational data (Symphony Health retrospective claims analysis). The latter constituted the third approach for quantifying drug wastage. The economic impact of dose reductions for ribociclib and palbociclib in postmenopausal women with previously untreated HR-positive/HER2-negative advanced breast cancer was assessed. Drug wastage was defined as drug doses that could not be used by a patient following a dose reduction. The cost of drug wastage was defined as the cost associated with an unused drug resulting from a dose reduction. The predicted results from the 2 models were compared with a previously published claims analysis that estimated the effect of treatment costs and drug wastage for palbociclib based on the observed dosing patterns from the Symphony Health Solutions database.. In the Markov model, relative to ribociclib, palbociclib users experienced drug wastage of $112,382 total, or $1,124 per treated patient, per year due to dose changes. In the pharmacy acquisition cost model, relative to ribociclib, palbociclib usage was associated with an increased cost of $7,196 per patient per year (based on a mid-cycle dose reduction) comprising dosing-based cost differences and drug wastage cost for palbociclib of $3,727. The previously published claims analysis found that palbociclib users experiencing a dose reduction had drug wastage costs of $5,471 per patient.. In both models, dose reductions for ribociclib patients resulted in no wastage, since unused tablets could be administered in subsequent cycles, while dose reductions for palbociclib resulted in drug wastage and increased costs. The results from both models were consistent with previously published results from the claims analysis, demonstrating drug wastage costs for palbociclib.. This study received financial support from Novartis Pharmaceuticals, which has products approved for treatment of breast cancer. Tang was employed by Novartis during this study; Zacker and Dalal are employed by Novartis and own company stock. Biskupiak, Brixner, and Oderda received payment from Novartis for this study. Brixner serves as a consultant for Millcreek Outcomes Group and also declares consulting fees from Abbvie, AstraZeneca, Abbott, Becton Dickinson, and Xcenda, unrelated to this study.

Topics: Aminopyridines; Antineoplastic Combined Chemotherapy Protocols; Breast Neoplasms; Cost-Benefit Analysis; Drug Costs; Drug Utilization; Evaluation Studies as Topic; Female; Health Care Costs; Humans; Middle Aged; Models, Economic; Piperazines; Purines; Pyridines; Randomized Controlled Trials as Topic; Retrospective Studies

Topics: Animals; Antineoplastic Agents; Apoptosis; Breast Neoplasms; Cell Cycle Checkpoints; Cell Differentiation; Cell Line, Tumor; Cell Proliferation; Cyclin-Dependent Kinase 4; Cyclin-Dependent Kinase 9; Female; Histone Deacetylase 1; Histone Deacetylase Inhibitors; Humans; Male; Mice; Mice, Inbred BALB C; Models, Molecular; Phosphorylation; Structure-Activity Relationship; Substrate Specificity; Tumor Suppressor Protein p53

While deregulation of the cyclin D1-CDK4/6-retinoblastoma pathway is common in hormone receptor positive (HR+) breast cancer, Rb is usually intact in HR+ breast cancer, and targeted CDK 4/6 inhibitors that act upstream of Rb, are routinely being utilized in clinical practice. However, factors that can lead to clinical resistance to CDK 4/6 inhibitors are not known.. We identified patients who had pre- and post-genotyping in tissue and peripheral blood samples after receiving CDK 4/6 inhibitors. Genotyping was carried out in tumor tissue or blood collected before start of CDK 4/6 inhibitor and after disease progression on CDK 4/6 inhibitor, covering more than 90% of the coding region in RB1.. We identified detectable acquired RB1 mutations in circulating tumor DNA (ctDNA) after exposure to CDK4/6 inhibitor (palbociclib, palbociclib, ribociclib) for 5, 8, and 13 months, respectively, in three patients. The RB1 mutations included substitution in donor splicing site of exon 8 of the RB1 gene in patient #1; substitution in donor splicing site of exon 22 of RB1 gene, exon 19 deletion, exon 3 insertion in patient #2; and RB1 exon 16 H483Y mutation in patient #3. None of these RB1 mutations were present in the pre-CDK 4/6 specimen highlighting these molecular alterations, which lead to functional loss of Rb1, likely emerged under selective pressure from the CDK4/6 inhibitor potentially confering therapeutic resistance.. This is the first clinical report to describe the emergence of somatic RB1 mutations after exposure to palbociclib or ribociclib, in patients with metastatic breast cancer. Further research is needed to validate these findings, identify how these mutations temporally emerge under selective pressure of CDK 4/6 inhibitor, and develop rational therapeutic strategies.

Topics: Aged; Aminopyridines; Antineoplastic Agents; Breast Neoplasms; Drug Resistance, Neoplasm; Female; Genotype; Humans; Middle Aged; Mutation; Piperazines; Protein Kinase Inhibitors; Purines; Pyridines; Retinoblastoma Binding Proteins; Ubiquitin-Protein Ligases

Breast cancer (BC) remains the most frequently diagnosed cancer and the most common cause of cancer death among women of all races worldwide. Over 80% of BC cases are hormone receptor (HR)-positive, comprised of luminal A and luminal B per molecular subtypes, imposing an urgent need to fully understand the mechanisms behind progression. Ribociclib is a selective cycline-dependent kinase 4 and 6 inhibitor. A phase 1 and a phase 3 trial have established a definitive role of ribociclib as frontline in the treatment of endocrine-sensitive advanced BC. Areas covered: Herein, the authors provide an overview of the data on ribociclib covering all aspects of the drug from its pharmacokinetics to efficacy and safety. The authors also provide their perspectives for the future. Expert opinion: Ribociclib is offering an opportunity to explore a new compound at the crossroads of different molecular activity and cell targets, which focus on endocrine-resistance reversal in multiple settings including early BC. Moreover, its activity against different subtypes of BC is being studied as is its immune-modulating effect. One cautionary note is that, in a market of concomitant similar competitors, a financial discussion will be mandatory.

Topics: Aminopyridines; Breast Neoplasms; Clinical Trials as Topic; Cyclin-Dependent Kinase 4; Cyclin-Dependent Kinase 6; Estrogen Receptor alpha; Female; Half-Life; Humans; Neoplasm Staging; Purines; Receptor, ErbB-2; T-Lymphocytes; Treatment Outcome

On March 13, 2017, the FDA approved ribociclib (KISQALI; Novartis Pharmaceuticals Corp.), a cyclin-dependent kinase 4/6 inhibitor, in combination with an aromatase inhibitor as initial endocrine-based therapy for the treatment of postmenopausal women with hormone receptor (HR)-positive, HER2-negative advanced or metastatic breast cancer. The approval was based on a randomized, double-blind, placebo-controlled, international clinical trial (MONALEESA-2). A total of 668 patients were randomized to receive either ribociclib plus letrozole (

Topics: Aminopyridines; Antineoplastic Agents; Breast Neoplasms; Clinical Trials as Topic; Drug Approval; Female; Humans; Neoplasm Metastasis; Neoplasm Staging; Postmenopause; Protein Kinase Inhibitors; Purines; Receptor, ErbB-2; Receptors, Estrogen; Receptors, Progesterone; Research Design; Treatment Outcome

Ribociclib is an orally active, highly selective inhibitor of cyclin-dependent kinase (CDK) 4 and 6. It is the second CDK 4/6 inhibitor approved for hormone receptor-positive breast cancer. The addition of ribociclib to an aromatase inhibitor has resulted in marked improvements in progression-free survival for patients with metastatic breast cancer.

Topics: Aminopyridines; Antineoplastic Combined Chemotherapy Protocols; Breast Neoplasms; Cyclin-Dependent Kinase 4; Female; Humans; Postmenopause; Purines

Topics: Aminopyridines; Antineoplastic Agents; Benzimidazoles; Biomarkers, Tumor; Breast Neoplasms; Circulating Tumor DNA; Class I Phosphatidylinositol 3-Kinases; Cyclin-Dependent Kinase 4; Cyclin-Dependent Kinase 6; Disease-Free Survival; Drug Resistance, Neoplasm; Estradiol; Female; Fulvestrant; Humans; Mutation; Piperazines; Protein Kinase Inhibitors; Purines; Pyridines; Retinoblastoma Binding Proteins; Ubiquitin-Protein Ligases

U.S. regulatory approvals of the cyclin-dependent kinase 4 and 6 (CDK 4/6) inhibitors ribociclib and palbociclib as add-ons to letrozole greatly enhance the prospects for treating postmenopausal women with hormone receptor-positive (HR+)/human epidermal receptor 2-negative (HER2-) advanced or metastatic breast cancer. Clinical trials have established that the combination of a CDK 4/6 inhibitor with letrozole can significantly improve progression-free survival (PFS) versus letrozole monotherapy and is safe and well tolerated. Cost-effectiveness studies are required to inform payers and clinical decision makers on the money value of combination treatment in clinical practice.. To evaluate the cost-effectiveness of ribociclib plus letrozole versus palbociclib plus letrozole and versus letrozole monotherapy in the first-line treatment of postmenopausal women with HR+/HER2- advanced or metastatic breast cancer from a U.S. private third-party payer perspective.. A partitioned survival model including 3 health states (progression free, with either overall response or stable disease; progressed disease; and death) simulated lifetime costs and outcomes over a 40-year lifetime horizon with a 1-month cycle length. Clinical efficacy data (PFS and overall survival [OS]) were derived from a phase III trial of ribociclib plus letrozole (MONALEESA-2; NCT01958021), a phase II trial of palbociclib plus letrozole (PALOMA-1; NCT00721409), and a Bayesian network meta-analysis. Health care costs included drug acquisition and monitoring, disease management, subsequent therapies, and serious drug-related adverse events. Effectiveness was measured in life-years, derived from survival projections, and in quality-adjusted life-years (QALYs), calculated from time spent in each state combined with health-state utility values. A one-way deterministic sensitivity analysis explored the impact of uncertainty in key model parameters on results, and probabilistic uncertainty was assessed through a Monte Carlo probabilistic sensitivity analysis.. Ribociclib plus letrozole was dominant versus palbociclib plus letrozole, with a cost saving of $43,037 and a gain of 0.086 QALYs. Compared with letrozole monotherapy, ribociclib plus letrozole was associated with an incremental cost of $144,915 and an incremental QALY of 0.689, equating to an incremental cost-effectiveness ratio of $210,369 per QALY. Key model drivers included OS HRs for palbociclib plus letrozole versus letrozole and for ribociclib plus letrozole versus letrozole, the PFS HR for palbociclib plus letrozole versus letrozole, PD health-state costs, utility of response, and cost discount rate. The probabilities that ribociclib plus letrozole was cost-effective versus letrozole at thresholds of $50,000, $100,000 and $200,000 per QALY gained were 1.6%, 6.3%, and 50.5%, respectively.. In the United States, ribociclib plus letrozole is a cost-effective alternative to palbociclib plus letrozole for the first-line treatment of postmenopausal women with HR+/HER2- advanced or metastatic breast cancer. Ribociclib plus letrozole is also cost-effective versus letrozole monotherapy at willingness-to-pay thresholds greater than $198,000 per QALY (for probabilistic analysis).. Funding for this study was provided by Novartis, which manufactures ribociclib and provided input on the study design and data collection, analysis, and interpretation. Mistry, May, Suri, and Young are employees of PAREXEL. Tang, Mishra, D. Bhattacharyya, and Dalal are employees of Novartis. S. Bhattacharyya was an employee of Novartis during the study period. Tang and Dalal hold stock in Novartis. Brixner, Oderda, and Biskupiak were paid by Millcreek Outcomes Group as consultants for work on this project. Brixner has also consulted for AstraZeneca, UCB, Regeneron, and Abbott.

Topics: Aminopyridines; Antineoplastic Combined Chemotherapy Protocols; Breast Neoplasms; Cost-Benefit Analysis; Disease-Free Survival; Female; Humans; Letrozole; Models, Biological; Models, Economic; Nitriles; Piperazines; Postmenopause; Protein Kinase Inhibitors; Purines; Pyridines; Receptor, ErbB-2; Receptors, Estrogen; Receptors, Progesterone; Survival Analysis; Treatment Outcome; Triazoles; United States

Topics: Aminopyridines; Breast; Breast Neoplasms; Female; Humans; Purines

Topics: Aminopyridines; Breast; Breast Neoplasms; Female; Humans; Purines

The combination of a cyclin-dependent kinase 4 and 6 (CDK 4/6) inhibitor with the aromatase inhibitor letrozole is a safe and effective alternative to letrozole monotherapy for first-line hormone receptor-positive (HR+)/human epidermal growth factor receptor 2-negative (HER2-) breast cancer. This study evaluates the budget impact of using the CDK 4/6 inhibitor ribociclib plus letrozole as a first-line treatment option for postmenopausal women with HR+/HER2- advanced breast cancer, from a United States (US) payer perspective.. A cohort-based budget impact model was used to calculate the incremental cost of introducing ribociclib plus letrozole over three years for the target population. The analysis compared two scenarios: treatment options excluding or including ribociclib plus letrozole. Market shares were derived from market research and the assumption was the introduction of ribociclib plus letrozole would only displace existing CDK-based therapies. Treatment duration was based on the median time to treatment discontinuation or median progression-free survival for first-line treatment, and on clinical trial data for second- and third-line treatment. Acquisition costs were based on wholesale acquisition costs and considered co-payment. Costs for drug administration and monitoring, subsequent therapy, and relevant adverse events were included.. Of 1 million insured members, 263 were eligible for CDK 4/6 inhibitor treatment. Cumulative total savings with ribociclib plus letrozole were $3.01M over three years, corresponding to a cumulative incremental cost saving of $318.11 per member treated per month.. In the US, ribociclib plus letrozole represents a cost-saving first-line treatment option for postmenopausal women with HR+/HER2- advanced breast cancer.

Topics: Aminopyridines; Antineoplastic Combined Chemotherapy Protocols; Breast Neoplasms; Budgets; Female; Humans; Letrozole; Postmenopause; Purines; Receptor, ErbB-2; Receptors, Estrogen; United States

Ribociclib is a CDK4-6 inhibitor recently approved by the Food and Drug Administration (FDA) and the European Medicines Agency (EMA) as first-line treatment for metastatic breast cancer (MBC). The pivotal trial showed a significant improvement in progression-free survival when compared to endocrine therapy alone. However, having a challenging toxicity profile in comparison with exclusive endocrine therapy, safety may be a concern when combined to radiotherapy (RT) with palliative approach. There are no available published data regarding the combination of ribociclib and palliative RT. We reported our preliminary experience on the first five patients treated at the Radiation Oncology Unit of the Florence University (Florence, Italy) giving palliative RT concomitant to ribociclib plus letrozole as first-line treatment for MBC.

Topics: Adult; Aged; Aminopyridines; Antineoplastic Agents; Breast Neoplasms; Female; Humans; Italy; Middle Aged; Palliative Care; Purines; Radiotherapy, Adjuvant

Topics: Aminopyridines; Antineoplastic Combined Chemotherapy Protocols; Aromatase Inhibitors; Benzimidazoles; Breast Neoplasms; Carcinoma, Lobular; Colonic Neoplasms; Cyclin-Dependent Kinase 4; Cyclin-Dependent Kinase 6; Female; Humans; Letrozole; Middle Aged; Neoplasm Metastasis; Piperazines; Protein Kinase Inhibitors; Purines; Pyridines; Receptor, ErbB-2; Receptors, Estrogen; Receptors, Progesterone

Topics: Aminopyridines; Anilides; Animals; Antineoplastic Agents; Apoptosis; Breast; Breast Neoplasms; Cell Cycle; Cell Line, Tumor; Cyclin-Dependent Kinase 9; Drug Screening Assays, Antitumor; Female; Humans; Lung; Lung Neoplasms; Mice; Mice, Inbred BALB C; Molecular Docking Simulation; Protein Kinase Inhibitors; Purines; Pyridines

Topics: Aminopyridines; Antineoplastic Agents; Breast Neoplasms; Cyclin-Dependent Kinase 4; Cyclin-Dependent Kinase 6; Drug Approval; Drug Industry; Female; Humans; Purines; United States; United States Food and Drug Administration

Ribociclib is an oral, small-molecule inhibitor of cyclin-dependent kinase (CDK) 4 and 6 that is under development by Novartis for the treatment of cancer. CDKs play an important role in cell cycle progression and cellular proliferation, and inhibition of these kinases with ribociclib results in G1 phase cell-cycle arrest. Ribociclib, in combination with an aromatase inhibitor, was recently approved in the USA for the first-line treatment of advanced breast cancer and has been submitted for approval in the EU for this indication. Ribociclib is undergoing further phase III investigations in breast cancer and is being evaluated in phase I or II trials for various solid tumour types and haematological malignancies. This article summarizes the milestones in the development of ribociclib leading to this first global approval for use as initial endocrine-based therapy for the treatment of postmenopausal women with hormone receptor-positive, human epidermal growth factor receptor 2-negative advanced or metastatic breast cancer.

Topics: Administration, Oral; Aminopyridines; Antineoplastic Agents; Antineoplastic Combined Chemotherapy Protocols; Aromatase Inhibitors; Breast Neoplasms; Clinical Trials as Topic; Cyclin-Dependent Kinase 4; Cyclin-Dependent Kinase 6; Drug Approval; Enzyme Inhibitors; Female; Humans; Purines; United States; United States Food and Drug Administration

Topics: Aminopyridines; Breast Neoplasms; Cyclin-Dependent Kinase 4; Cyclin-Dependent Kinase 6; Drug Approval; Drug Industry; Female; Humans; Purines; United States; United States Food and Drug Administration

Topics: Aminopyridines; Breast Neoplasms; Female; Humans; Molecular Targeted Therapy; Purines; Translational Research, Biomedical

Topics: Aminopyridines; Antineoplastic Agents; Breast Neoplasms; Cyclin-Dependent Kinase 4; Cyclin-Dependent Kinase 6; Female; Humans; Neoplasm Metastasis; Protein Kinase Inhibitors; Purines; Signal Transduction; Treatment Outcome

Topics: Aminopyridines; Antineoplastic Agents; Breast Neoplasms; Drug Costs; Female; Humans; Piperazines; Purines; Pyridines; State Medicine; United Kingdom

Dysregulation of cellular cycle is a key component of carcinogenesis and its targeting represents an interesting approach. Recently, the development of selective inhibitors of the cycle targeting the cyclin-dependent kinases (CDK) 4 and 6 revived interest in this therapeutic class after the failure of pan-inhibitors. Palbociclib, ribociclib, and abemaciclib are the 3 drugs with the most advanced development. They demonstrated preclinical activity in luminal breast cancer models and are under clinical evaluation. The first available studies demonstrate the value of these compounds with an improved prognosis of metastatic patients in combination with endocrine therapy (palbociclib, ribociclib) or in monotherapy (abemaciclib). The results of ongoing studies will clarify the role of these agents in our new strategies and the individualisation of biomarkers will help to define patients who benefit most from this approach.

Topics: Aminopyridines; Antineoplastic Agents; Benzimidazoles; Breast Neoplasms; Cell Cycle; Cell Cycle Checkpoints; Clinical Trials as Topic; Cyclin-Dependent Kinase 4; Cyclin-Dependent Kinase 6; Female; Humans; Neoplasms, Hormone-Dependent; Piperazines; Protein Kinase Inhibitors; Purines; Pyridines

Acquired resistance to cyclin-dependent kinases 4 and 6 (CDK4/6) small-molecule inhibitors in breast cancer arises through mechanisms that are yet uncharacterized. In this study, we used a kinome-wide siRNA screen to identify kinases that, when downregulated, yield sensitivity to the CDK4/6 inhibitor ribociclib. In this manner, we identified 3-phosphoinositide-dependent protein kinase 1 (PDK1) as a key modifier of ribociclib sensitivity in estrogen receptor-positive MCF-7 breast cancer cells. Pharmacologic inhibition of PDK1 with GSK2334470 in combination with ribociclib or palbociclib, another CDK4/6 inhibitor, synergistically inhibited proliferation and increased apoptosis in a panel of ER-positive breast cancer cell lines. Ribociclib-resistant breast cancer cells selected by chronic drug exposure displayed a relative increase in the levels of PDK1 and activation of the AKT pathway. Analysis of these cells revealed that CDK4/6 inhibition failed to induce cell-cycle arrest or senescence. Mechanistic investigations showed that resistant cells coordinately upregulated expression of cyclins A, E, and D1, activated phospho-CDK2, and phospho-S477/T479 AKT. Treatment with GSK2334470 or the CDK2 inhibitor dinaciclib was sufficient to reverse these events and to restore the sensitivity of ribociclib-resistant cells to CDK4/6 inhibitors. Ribociclib, in combination with GSK2334470 or the PI3Kα inhibitor alpelisib, decreased xenograft tumor growth more potently than each drug alone. Taken together, our results highlight a role for the PI3K-PDK1 signaling pathway in mediating acquired resistance to CDK4/6 inhibitors.

Topics: Aminopyridines; Animals; Apoptosis; Breast Neoplasms; Cell Cycle Checkpoints; Cell Proliferation; Cyclin-Dependent Kinase 4; Cyclin-Dependent Kinase 6; Drug Resistance, Neoplasm; Drug Synergism; Female; Humans; Indazoles; MCF-7 Cells; Mice; Phosphatidylinositol 3-Kinases; Piperazines; Protein Serine-Threonine Kinases; Purines; Pyridines; Pyrimidines; Pyruvate Dehydrogenase Acetyl-Transferring Kinase; Receptors, Estrogen; Xenograft Model Antitumor Assays

Topics: Aminopyridines; Antineoplastic Agents; Breast Neoplasms; Carcinoma; Cyclin-Dependent Kinase 4; Cyclin-Dependent Kinase 6; Estradiol; Everolimus; Female; Fulvestrant; Humans; Molecular Targeted Therapy; Pathology, Molecular; Piperazines; Precision Medicine; Purines; Pyridines; Receptor, ErbB-2; Receptors, Estrogen; Tamoxifen; TOR Serine-Threonine Kinases; Trastuzumab

Topics: Aminopyridines; Antineoplastic Agents; Biomarkers, Tumor; Breast Neoplasms; Disease Progression; Disease-Free Survival; Female; Humans; Protein Kinase Inhibitors; Purines; Receptor, ErbB-2; Receptors, Estrogen; Receptors, Progesterone; Treatment Outcome

The combination of antiestrogen therapy and ribociclib, an investigational CDK4/6 inhibitor, led to improved outcomes in women with metastatic HR-positive, HER2-negative breast cancer, according to findings presented at a meeting of the European Society for Medical Oncology. The combination significantly increased progression-free survival compared with letrozole alone in a large phase III trial-data that could lead to FDA approval.

Topics: Aminopyridines; Antineoplastic Combined Chemotherapy Protocols; Breast Neoplasms; Clinical Trials as Topic; Disease-Free Survival; Female; Humans; Letrozole; Nitriles; Purines; Treatment Outcome; Triazoles

Topics: Aminopyridines; Antineoplastic Agents; Benzimidazoles; Breast Neoplasms; Clinical Trials, Phase II as Topic; Cyclin-Dependent Kinase 4; Cyclin-Dependent Kinase 6; Female; Humans; Molecular Targeted Therapy; Piperazines; Protein Kinase Inhibitors; Purines; Pyridines; Receptors, Estrogen; Research; Treatment Outcome

Topics: Aminopyridines; Antineoplastic Agents; Benzimidazoles; Breast Neoplasms; Cell Cycle; Clinical Trials, Phase I as Topic; Cyclin-Dependent Kinase 4; Cyclin-Dependent Kinase 6; Female; Humans; Piperazines; Proto-Oncogene Proteins; Proto-Oncogene Proteins p21(ras); Purines; Pyridines; Randomized Controlled Trials as Topic; ras Proteins; Receptors, Estrogen