bmn-673 and Breast-Neoplasms

Talazoparib is an oral PARP inhibitor approved for locally advanced/metastatic breast cancer. There is no consensus, however, as to whether it is better used as a first-line treatment or after other therapies in patients with

Topics: BRCA1 Protein; Breast Neoplasms; Female; Humans; Phthalazines; Quality of Life

In this review, the authors highlight the relevant clinical trials of talazoparib, as well as, safety, tolerability, and quality of life considerations. They also examine putative response and resistance mechanisms, and rational combinatorial therapeutic strategies under development.. Talazoparib has been a major advance in the treatment of germline

Topics: BRCA1 Protein; BRCA2 Protein; Breast Neoplasms; Female; Germ-Line Mutation; Humans; Phthalazines; Poly(ADP-ribose) Polymerase Inhibitors; Quality of Life

The poly-(ADP-ribose) polymerase (PARP) inhibitors olaparib and talazoparib, have recently been approved for use in patients with metastatic breast cancer (BC) and germline BRCA 1 or 2 mutations due to improved progression-free survival compared to chemotherapy. An increasing number of clinical trials are evaluating the role of PARP inhibitors (PARPi) in BC, alone and in combination with other therapies (including immunotherapy), as well as in earlier stages of the disease. This review describes the unique mechanism of action of these drugs and puts into clinical context the results of pivotal clinical trials. We also discuss the future development of PARPi in BC, their potential combination with other strategies, including chemotherapy and immune-checkpoint inhibitors, and the impact of these treatments in current genetic counselling.

Topics: Antineoplastic Agents; BRCA1 Protein; BRCA2 Protein; Breast Neoplasms; Female; Humans; Immunotherapy; Mutation; Phthalazines; Piperazines; Poly(ADP-ribose) Polymerase Inhibitors; Poly(ADP-ribose) Polymerases

Genetic complexity and DNA damage repair defects are common in different cancer types and can induce tumor-specific vulnerabilities. Poly(ADP-ribose) polymerase (PARP) inhibitors exploit defects in the DNA repair pathway through synthetic lethality and have emerged as promising anticancer therapies, especially in tumors harboring deleterious germline or somatic breast cancer susceptibility gene (BRCA) mutations. However, the utility of PARP inhibitors could be expanded beyond germline BRCA1/2 mutated cancers by causing DNA damage with cytotoxic agents in the presence of a DNA repair inhibitor. US Food and Drug Administration (FDA)-approved PARP inhibitors include olaparib, rucaparib, and niraparib, while veliparib is in the late stage of clinical development. Talazoparib inhibits PARP catalytic activity, trapping PARP1/2 on damaged DNA, and it has been approved by the US FDA for the treatment of metastatic germline BRCA1/2 mutated breast cancers in October 2018. The talazoparib side effect profile more closely resembles traditional chemotherapeutics rather than other clinically approved PARP inhibitors. In this review, we discuss the scientific evidence that has emerged from both experimental and clinical studies in the development of talazoparib. Future directions will include optimizing combination therapy with chemotherapy, immunotherapies and targeted therapies, and in developing and validating biomarkers for patient selection and stratification, particularly in malignancies with 'BRCAness'.

Topics: Antineoplastic Agents; Breast Neoplasms; Female; Humans; Ovarian Neoplasms; Phthalazines; Poly(ADP-ribose) Polymerase Inhibitors; Poly(ADP-ribose) Polymerases

Breast cancer is the most commonly diagnosed cancer and is the leading cause of cancer death in women worldwide. Both talazoparib and olaparib are approved by the US Food and Drug Administration for treating. To compare the efficacy, safety, and acceptability of single-agent poly (ADP-ribose) polymerase (PARP) inhibitors for patients with. We included two trials comprising 733 participants. Compared with talazoparib, olaparib was not associated with improved PFS (. Both talazoparib and olaparib have similar efficacy, safety, and acceptability in patients with. We performed a systematic review and network meta-analysis. We performed a systematic search of Web of Science, Embase, PubMed, Medline, ClinicalTrials.gov, the Cochrane Central Register of Controlled Trials, and the World Health Organization International Clinical Trials Registry Platform, and international registers for published and unpublished double-blind randomized controlled trials from database inception to July 20, 2019. The pooled estimates of hazard ratios (HR) with 95% credible intervals (CrIs) were calculated for PFS, OS, and the time to deterioration of quality of life (QoL). The pooled estimates of odds ratio (

Topics: Anemia; Breast Neoplasms; Female; Genes, BRCA1; Humans; Mutation; Neoplasm Metastasis; Network Meta-Analysis; Neutropenia; Phthalazines; Piperazines; Poly(ADP-ribose) Polymerase Inhibitors; Progression-Free Survival; Proportional Hazards Models; Quality of Life; Receptor, ErbB-2; Survival Rate; Treatment Outcome

Genomic instability is a hallmark of cancer, and often is the result of altered DNA repair capacities in tumour cells. DNA damage repair defects are common in different cancer types; these alterations can also induce tumour-specific vulnerabilities that can be exploited therapeutically. In 2009, a first-in-man clinical trial of the poly(ADP-ribose) polymerase (PARP) inhibitor olaparib clinically validated the synthetic lethal interaction between inhibition of PARP1, a key sensor of DNA damage, and BRCA1/BRCA2 deficiency. In this review, we summarize a decade of PARP inhibitor clinical development, a work that has resulted in the registration of several PARP inhibitors in breast (olaparib and talazoparib) and ovarian cancer (olaparib, niraparib and rucaparib, either alone or following platinum chemotherapy as maintenance therapy). Over the past 10 years, our knowledge on the mechanism of action of PARP inhibitor as well as how tumours become resistant has been extended, and we summarise this work here. We also discuss opportunities for expanding the precision medicine approach with PARP inhibitors, identifying a wider population who could benefit from this drug class. This includes developing and validating better predictive biomarkers for patient stratification, mainly based on homologous recombination defects beyond BRCA1/BRCA2 mutations, identifying DNA repair deficient tumours in other cancer types such as prostate or pancreatic cancer, or by designing combination therapies with PARP inhibitors.

Topics: BRCA1 Protein; BRCA2 Protein; Breast Neoplasms; Female; Genomic Instability; Humans; Indazoles; Indoles; Ovarian Neoplasms; Phthalazines; Piperazines; Piperidines; Poly (ADP-Ribose) Polymerase-1; Poly(ADP-ribose) Polymerase Inhibitors

Talazoparib tosylate (BMN-673, Talzenna; Pfizer) is an oral poly [ADP-ribose] polymerase (PARP) inhibitor (PARPi) that has been approved by the U.S. Food and Drug Administration (FDA) and the European Medicines Agency (EMA) for the treatment of germline BRCA-mutated locally advanced or metastatic breast cancer (BC). In preclinical and clinical studies, talazoparib exerted superior efficacy and offered a significant clinical benefit in advanced or metastatic BC patients harboring germline BRCA mutations compared with other PARPi and standard chemotherapy regimens through the concept of synthetic lethality. Thus, this review provides insight into the results of preclinical and clinical studies, highlights the current challenges of talazoparib and suggests innovative approaches to further improve its clinical efficacy and expand the use of talazoparib in advanced BC and/or triple-negative BC treatments beyond BRCA mutations.

Topics: BRCA1 Protein; Breast Neoplasms; Humans; Mutation; Phthalazines; Poly(ADP-ribose) Polymerase Inhibitors

The single agent activity of PARP inhibitors (PARPi) in germline BRCA mutated (gBRCAm) breast and ovarian cancer suggests untapped potential for this new class of drug in breast cancer. The US Food and Drug Administration has approved three PARPi (olaparib, rucaparib, and niraparib) so far to treat certain ovarian cancers, including those with gBRCAm and olaparib for treatment of gBRCAm breast cancers. Several PARPi are now under clinical development for breast cancer in the various treatment settings. Recently, two phase III trials of olaparib (OlympiaD) and talazoparib (EMBRACA) demonstrated 3-month progression-free survival improvement with PARPi compared to physician's choice single agent chemotherapy in metastatic gBRCAm breast cancer. To date, PARPi seems less efficacious in metastatic breast cancer patients than those with BRCA mutated platinum-sensitive recurrent ovarian cancer, perhaps reflecting the biologic heterogeneity and low somatic BRCA mutation rate in breast cancer. The use of PARPi is gradually evolving, including combination strategies with chemotherapy, targeted agents, radiotherapy, or immunotherapy in women with and without gBRCAm. The role of predictive biomarkers, including molecular signatures and homologous recombination repair deficiency scores based on loss of heterozygosity and other structural genomic aberrations, will be crucial to identify a subgroup of patients who may have benefit from PARPi. An improved understanding of the mechanisms underlying PARPi clinical resistance will also be important to enable the development of new approaches to increase efficacy. This is a field rich in opportunity, and the coming years should see a better understanding of which breast cancer patients we should treat with PARPi and where these agents should come in over the course of treatment.

Topics: BRCA1 Protein; BRCA2 Protein; Breast Neoplasms; Female; Humans; Indazoles; Indoles; Neoplasm Recurrence, Local; Phthalazines; Piperazines; Piperidines; Poly(ADP-ribose) Polymerase Inhibitors; Poly(ADP-ribose) Polymerases; Progression-Free Survival

PARP enzymes are essential for DNA damage repair. Cancers with defective homologous recombination DNA repair, such has

Topics: Antineoplastic Combined Chemotherapy Protocols; BRCA1 Protein; BRCA2 Protein; Breast Neoplasms; DNA Repair; Female; Germ-Line Mutation; Humans; Neoplasm Staging; Phthalazines; Piperazines; Poly(ADP-ribose) Polymerase Inhibitors; Poly(ADP-ribose) Polymerases; Randomized Controlled Trials as Topic; Synthetic Lethal Mutations; Treatment Outcome

Talazoparib (TALZENNA™) is an oral inhibitor of the polyadenosine 5'-diphosphoribose polymerase (PARP) enzymes, which play a critical role in repairing DNA single-strand breaks. It has been developed by Pfizer and was recently approved in the USA for the treatment of adults with deleterious or suspected deleterious germline BRCA-mutated, human epidermal growth factor receptor 2 (HER2)-negative, locally advanced or metastatic breast cancer (as detected by a US FDA-approved assay). A regulatory assessment for talazoparib in this patient population is underway in the EU, with talazoparib also undergoing development for use in metastatic castration-resistant prostate cancer and various solid tumours, and as neoadjuvant therapy in early triple negative breast cancer. This article summarizes the milestones in the development of talazoparib leading to its first approval for the treatment of adults with deleterious or suspected deleterious germline BRCA-mutated, HER2-negative, locally advanced or metastatic breast cancer.

Topics: Antineoplastic Agents; BRCA1 Protein; Breast Neoplasms; Drug Approval; Drug Therapy, Combination; Humans; Phthalazines; Poly(ADP-ribose) Polymerase Inhibitors; Receptor, ErbB-2; United States; United States Food and Drug Administration

Talazoparib, a poly(ADP-ribose) polymerase enzyme inhibitor, is approved for the treatment of patients with germline BRCA1/2 (gBRCA1/2)-mutated HER2-negative advanced breast cancer. This two-part study, a recently published dose-escalation part followed by the dose-expansion part reported here, evaluated the efficacy and safety of talazoparib in Japanese patients with gBRCA1/2-mutated advanced breast cancer.. In this open-label, multicenter phase 1 study (NCT03343054), the primary endpoint of the dose-expansion part was confirmed objective response rate (ORR), determined by investigator assessment (RECIST 1.1). Secondary endpoints included progression-free survival (PFS), overall survival (OS), safety, and pharmacokinetics. Patients received the recommended phase 2 dose (1 mg/day; 0.75 mg/day moderate renal impairment).. Nineteen Japanese patients with gBRCA1/2-mutated locally advanced or metastatic breast cancer were enrolled. Confirmed ORR was 57.9% (11/19; 90% confidence interval [CI] 36.8-77.0). Stable disease was observed in 36.8% (7/19) of patients. Per investigator assessment, median PFS was 7.2 months (95% CI 4.1-not estimable) and 12-month OS rate was 84.7% (90% CI 57.5-95.1). Median OS was not reached; 17/19 patients were alive and censored at 12 months. All patients experienced treatment-related adverse events (AEs); the majority were hematologic. The most common treatment-related AE was anemia (68.4%; [13/19]). Grade 3/4 treatment-related AEs were observed in 52.6% (10/19) of patients. During the safety period, there were no grade 5 treatment-emergent AEs, treatment-related serious AEs, or deaths.. In Japanese patients with gBRCA mutations and locally advanced or metastatic breast cancer, talazoparib monotherapy was generally well tolerated and resulted in clinically meaningful ORRs.. NCT03343054.

Topics: Antineoplastic Agents; Breast Neoplasms; Female; Germ Cells; Germ-Line Mutation; Humans; Japan; Poly(ADP-ribose) Polymerase Inhibitors; Poly(ADP-ribose) Polymerases

Talazoparib, a PARP inhibitor, is active in germline BRCA1 and BRCA2 (gBRCA1/2)-mutant advanced breast cancer, but its activity beyond gBRCA1/2 is poorly understood. We conducted Talazoparib Beyond BRCA ( NCT02401347 ), an open-label phase II trial, to evaluate talazoparib in patients with pretreated advanced HER2-negative breast cancer (n = 13) or other solid tumors (n = 7) with mutations in homologous recombination (HR) pathway genes other than BRCA1 and BRCA2. In patients with breast cancer, four patients had a Response Evaluation Criteria in Solid Tumors (RECIST) partial response (overall response rate, 31%), and three additional patients had stable disease of ≥6 months (clinical benefit rate, 54%). All patients with germline mutations in PALB2 (gPALB2; encoding partner and localizer of BRCA2) had treatment-associated tumor regression. Tumor or plasma circulating tumor DNA (ctDNA) HR deficiency (HRD) scores were correlated with treatment outcomes and were increased in all gPALB2 tumors. In addition, a gPALB2-associated mutational signature was associated with tumor response. Thus, talazoparib has been demonstrated to have efficacy in patients with advanced breast cancer who have gPALB2 mutations, showing activity in the context of HR pathway gene mutations beyond gBRCA1/2.

Topics: BRCA1 Protein; BRCA2 Protein; Breast Neoplasms; Circulating Tumor DNA; Female; Homologous Recombination; Humans; Mutation; Poly(ADP-ribose) Polymerase Inhibitors

This study evaluated factors that influence the cost-effectiveness of talazoparib, particularly for patients with a germline breast-cancer-gene-(brca)-mutation and locally advanced or metastasized breast cancer within the context of the German healthcare system. We constructed a partitioned survival model to compare medical costs and treatment effectiveness for patients with such cancers over 45 months. Transition probabilities were derived from survival data from a randomized Phase-III EMBRACA trial, utilities based on published reports, and costs in Euros, which included costs for drug acquisition, clinical monitoring, and treatment of adverse events. Willingness-to-pay thresholds were set to be multiples of the current German per capita gross domestic product. Treatment with talazoparib led to a gain of 0.32 life-years (0.22 quality-adjusted life-years). The mean total cost of €84,003 for talazoparib and €12,741 for standard therapy resulted in an incremental cost-effectiveness ratio of €223,246 per life-year and €323,932 per quality-adjusted life-year gained, indicating that talazoparib is unlikely to be cost-effective at current pricing.

Topics: Breast; Breast Neoplasms; Cost-Benefit Analysis; Female; Germany; Humans; Neoplasms, Second Primary

We evaluated study outcomes in patients enrolled in Asian regions in the phase III EMBRACA trial of talazoparib vs. chemotherapy.. Patients with human epidermal growth factor receptor 2-negative germline BRCA1/2-mutated advanced breast cancer who received prior chemotherapy were randomized 2:1 to talazoparib 1 mg/day or chemotherapy (physician's choice). Primary endpoint was progression-free survival (PFS) per independent central review in the intent-to-treat (ITT) population. This post-hoc analysis evaluated efficacy/safety endpoints in the ITT population of patients enrolled in Asian regions.. Thirty-three patients were enrolled at Asian sites (talazoparib, n=23; chemotherapy, n=10). Baseline characteristics were generally comparable with the overall EMBRACA population. In Asian patients, median PFS was 9.0 months (95% confidence interval [CI], 3.0 to 15.2) for talazoparib and 7.1 months (95% CI, 1.2 to not reached) for chemotherapy (hazard ratio [HR], 0.74 [95% CI, 0.22 to 2.44]). Objective response rate was numerically higher for talazoparib vs. chemotherapy (62.5% [95% CI, 35.4 to 84.8] vs. 25.0% [95% CI, 3.2 to 65.1]). Median overall survival was 20.7 months (95% CI, 9.4 to 40.1) versus 21.2 months (95% CI, 2.7 to 35.0) (HR, 1.41 [95% CI, 0.49 to 4.05]). In Asian patients, fewer grade 3/4 adverse events (AEs), serious AEs (SAEs), grade 3/4 SAEs, and AEs resulting in dose reduction/discontinuation occurred with talazoparib than chemotherapy; for talazoparib, the frequency of these events was lower in Asian patients versus overall EMBRACA population.. In this subgroup analysis, talazoparib numerically improved efficacy versus chemotherapy and was generally well tolerated in Asian patients, with fewer grade 3/4 treatment-emergent AE (TEAEs), SAEs, and TEAEs leading to dose modification vs. the overall EMBRACA population.

Topics: Adult; Antineoplastic Combined Chemotherapy Protocols; Asia; BRCA1 Protein; BRCA2 Protein; Breast Neoplasms; Capecitabine; Deoxycytidine; Female; Follow-Up Studies; Furans; Gemcitabine; Germ-Line Mutation; Humans; Ketones; Middle Aged; Phthalazines; Prognosis; Receptor, ErbB-2; Survival Rate; Vinorelbine

Talazoparib has demonstrated efficacy in patients with. Eligibility included 1 cm or larger invasive tumor and g. Neoadjuvant single-agent oral talazoparib once per day for 6 months without chemotherapy produced substantial RCB-0 rate with manageable toxicity. The substantive pathologic response to single-agent talazoparib supports the larger, ongoing neoadjuvant trial (ClinicalTrials.gov identifier: NCT03499353).

Topics: Administration, Oral; Adult; BRCA1 Protein; BRCA2 Protein; Breast Neoplasms; Chemotherapy, Adjuvant; Female; Germ-Line Mutation; Humans; Medication Adherence; Middle Aged; Neoadjuvant Therapy; Phthalazines; Pilot Projects; Poly(ADP-ribose) Polymerase Inhibitors; Triple Negative Breast Neoplasms

In the EMBRACA phase III study (NCT01945775), talazoparib was associated with a significantly prolonged progression-free survival (PFS) compared with physician's choice of chemotherapy (PCT) in germline BRCA1/2-mutated HER2-negative advanced breast cancer (ABC). Herein, the safety profile of talazoparib is explored in detail.. Overall, 412 patients received ≥1 dose of talazoparib (n = 286) or PCT (n = 126). Adverse events (AEs) were evaluated, including timing, duration, and potential overlap of selected AEs. The relationship between talazoparib plasma exposure and grade ≥3 anemia was analyzed. Time-varying Cox proportional hazard models assessed the impact of dose reductions on PFS. Patient-reported outcomes (PROs) in patients with common AEs and health resource utilization (HRU) were assessed in both treatment arms.. The most common AEs with talazoparib were hematologic (195 [68.2%] patients) and typically occurred within the first 3-4 months of receiving talazoparib. Grade 3-4 anemia lasted approximately 7 days for both arms. Overlapping grade 3-4 hematologic AEs were infrequent with talazoparib. Higher talazoparib exposure was associated with grade ≥3 anemia. Permanent discontinuation of talazoparib due to hematologic AEs was low (<2%). A total of 150 (52.4%) patients receiving talazoparib had AEs associated with dose reduction. Hematologic toxicities were managed by supportive care medication (including transfusion) and dose modifications. Among patients with anemia or nausea and/or vomiting AEs, PROs favored talazoparib. After accounting for the treatment-emergent period, talazoparib was generally associated with a lower rate of hospitalization and supportive care medication use compared with chemotherapy.. Talazoparib was associated with superior efficacy, favorable PROs, and lower HRU rate versus chemotherapy in gBRCA-mutated ABC. Toxicities were manageable with talazoparib dose modification and supportive care.. Talazoparib was generally well tolerated in patients with germline BRCA-mutated HER2-negative advanced breast cancer in the EMBRACA trial. Common toxicities with talazoparib were primarily hematologic and infrequently resulted in permanent drug discontinuation (<2% of patients discontinued talazoparib due to hematologic toxicity). Hematologic toxicities typically occurred during the first 3-4 months of treatment and were managed by dose modifications and supportive care measures. A significant efficacy benefit, improved patient-reported outcomes, lower rate of health resource utilization and a tolerable safety profile support incorporating talazoparib into routine management of germline BRCA-mutated locally advanced/metastatic breast cancer.

Topics: Antineoplastic Combined Chemotherapy Protocols; Breast Neoplasms; Female; Germ Cells; Germ-Line Mutation; Humans; Phthalazines; Poly(ADP-ribose) Polymerase Inhibitors

In the phase 3 EMBRACA trial, treatment with the poly(ADP-ribose) polymerase inhibitor, talazoparib, led to significantly improved progression-free survival (PFS) compared with chemotherapy (hazard ratio, 0.54; 95% confidence interval, 0.41-0.71; P < .0001). We conducted an exposure-efficacy analysis using EMBRACA data from 285 patients who were treated with talazoparib and had available pharmacokinetic parameters to evaluate the effect of talazoparib exposure (time-varying average talazoparib concentration [C

Topics: Adult; Aged; Aged, 80 and over; Antineoplastic Agents; Breast Neoplasms; Dose-Response Relationship, Drug; Female; Genes, BRCA1; Genes, BRCA2; Germ-Line Mutation; Humans; Maximum Tolerated Dose; Middle Aged; Phthalazines; Poly(ADP-ribose) Polymerase Inhibitors; Progression-Free Survival; Proportional Hazards Models; Time Factors; Treatment Outcome

Poly(ADP-ribose) polymerase inhibitors, such as talazoparib, may affect hematopoiesis. This analysis characterized the relationship between talazoparib exposure and the most common grade ≥ 3 hematopoietic adverse events (AEs) leading to dose modification in the phase 2 (ABRAZO) and phase 3 (EMBRACA) trials. The relationship between time-varying average talazoparib concentration (C

Topics: Administration, Oral; Adult; Aged; Aged, 80 and over; Anemia; Antineoplastic Agents; Breast Neoplasms; Dose-Response Relationship, Drug; Drug Administration Schedule; Drug Dosage Calculations; Female; Genes, BRCA1; Genes, BRCA2; Germ-Line Mutation; Humans; Middle Aged; Mutation; Neutropenia; Phthalazines; Poly(ADP-ribose) Polymerase Inhibitors; Prognosis; Proportional Hazards Models; Thrombocytopenia

In EMBRACA, talazoparib prolonged progression-free survival versus chemotherapy (hazard ratio [HR] 0.542 [95% confidence interval (CI) 0.413-0.711]; P < 0.0001) and improved patient-reported outcomes (PRO) in germline BRCA1/2 (gBRCA1/2)-mutated advanced breast cancer (ABC). We report final overall survival (OS).. This randomized phase III trial enrolled patients with gBRCA1/2-mutated HER2-negative ABC. Patients received talazoparib or physician's choice of chemotherapy. OS was analyzed using stratified HR and log-rank test and prespecified rank-preserving structural failure time model to account for subsequent treatments.. A total of 431 patients were entered in a randomized study (287 talazoparib/144 chemotherapy) with 412 patients treated (286 talazoparib/126 chemotherapy). By 30 September 2019, 216 deaths (75.3%) occurred for talazoparib and 108 (75.0%) chemotherapy; median follow-up was 44.9 and 36.8 months, respectively. HR for OS with talazoparib versus chemotherapy was 0.848 (95% CI 0.670-1.073; P = 0.17); median (95% CI) 19.3 months (16.6-22.5 months) versus 19.5 months (17.4-22.4 months). Kaplan-Meier survival percentages (95% CI) for talazoparib versus chemotherapy: month 12, 71% (66% to 76%)/74% (66% to 81%); month 24, 42% (36% to 47%)/38% (30% to 47%); month 36, 27% (22% to 33%)/21% (14% to 29%). Most patients received subsequent treatments: for talazoparib and chemotherapy, 46.3%/41.7% received platinum and 4.5%/32.6% received a poly(ADP-ribose) polymerase (PARP) inhibitor, respectively. Adjusting for subsequent PARP and/or platinum use, HR for OS was 0.756 (95% bootstrap CI 0.503-1.029). Grade 3-4 adverse events occurred in 69.6% (talazoparib) and 64.3% (chemotherapy) patients, consistent with previous reports. Extended follow-up showed significant overall improvement and delay in time to definitive clinically meaningful deterioration in global health status/quality of life and breast symptoms favoring talazoparib versus chemotherapy (P < 0.01 for all), consistent with initial analyses.. In gBRCA1/2-mutated HER2-negative ABC, talazoparib did not significantly improve OS over chemotherapy; subsequent treatments may have impacted analysis. Safety was consistent with previous observations. PRO continued to favor talazoparib.

Topics: Antineoplastic Combined Chemotherapy Protocols; BRCA1 Protein; Breast Neoplasms; Germ Cells; Germ-Line Mutation; Humans; Phthalazines; Poly(ADP-ribose) Polymerase Inhibitors; Quality of Life

To assess talazoparib activity in germline. ABRAZO (NCT02034916) was a two-cohort, two-stage, phase II study of talazoparib (1 mg/day) in germline. We enrolled 84 patients (cohort 1,. Talazoparib exhibited promising antitumor activity in patients with advanced breast cancer and germline

Topics: Adult; Aged; Antineoplastic Combined Chemotherapy Protocols; BRCA1 Protein; BRCA2 Protein; Breast Neoplasms; Cohort Studies; Drug Resistance, Neoplasm; Female; Follow-Up Studies; Germ-Line Mutation; Humans; Middle Aged; Neoplasm Metastasis; Phthalazines; Platinum; Poly(ADP-ribose) Polymerase Inhibitors; Prognosis; Salvage Therapy

The poly(adenosine diphosphate-ribose) inhibitor talazoparib has shown antitumor activity in patients with advanced breast cancer and germline mutations in BRCA1 and BRCA2 ( BRCA1/2).. We conducted a randomized, open-label, phase 3 trial in which patients with advanced breast cancer and a germline BRCA1/2 mutation were assigned, in a 2:1 ratio, to receive talazoparib (1 mg once daily) or standard single-agent therapy of the physician's choice (capecitabine, eribulin, gemcitabine, or vinorelbine in continuous 21-day cycles). The primary end point was progression-free survival, which was assessed by blinded independent central review.. Of the 431 patients who underwent randomization, 287 were assigned to receive talazoparib and 144 were assigned to receive standard therapy. Median progression-free survival was significantly longer in the talazoparib group than in the standard-therapy group (8.6 months vs. 5.6 months; hazard ratio for disease progression or death, 0.54; 95% confidence interval [CI], 0.41 to 0.71; P<0.001). The interim median hazard ratio for death was 0.76 (95% CI, 0.55 to 1.06; P=0.11 [57% of projected events]). The objective response rate was higher in the talazoparib group than in the standard-therapy group (62.6% vs. 27.2%; odds ratio, 5.0; 95% CI, 2.9 to 8.8; P<0.001). Hematologic grade 3-4 adverse events (primarily anemia) occurred in 55% of the patients who received talazoparib and in 38% of the patients who received standard therapy; nonhematologic grade 3 adverse events occurred in 32% and 38% of the patients, respectively. Patient-reported outcomes favored talazoparib; significant overall improvements and significant delays in the time to clinically meaningful deterioration according to both the global health status-quality-of-life and breast symptoms scales were observed.. Among patients with advanced breast cancer and a germline BRCA1/2 mutation, single-agent talazoparib provided a significant benefit over standard chemotherapy with respect to progression-free survival. Patient-reported outcomes were superior with talazoparib. (Funded by Medivation [Pfizer]; EMBRACA ClinicalTrials.gov number, NCT01945775 .).

Topics: Adult; Aged; Aged, 80 and over; Antineoplastic Agents; Breast Neoplasms; Disease-Free Survival; Female; Genes, BRCA1; Genes, BRCA2; Germ-Line Mutation; Humans; Middle Aged; Patient Reported Outcome Measures; Phthalazines; Poly(ADP-ribose) Polymerase Inhibitors; Quality of Life; Survival Analysis

In the EMBRACA phase III trial, talazoparib (1 mg daily, orally) demonstrated a statistically significant improvement in PFS versus physician's choice of chemotherapy (PCT; capecitabine, eribulin, gemcitabine, or vinorelbine) in patients with HER2-negative advanced breast cancer carrying a germline BRCA1/2 mutation; we evaluated patient-reported outcomes (PROs).. Patients were randomized 2 : 1 to receive talazoparib or PCT. PROs were assessed at day 1 (baseline), the start of each treatment cycle (every 3 weeks), and at the end of treatment, using the European Organisation for Research and Treatment of Cancer Quality of Life Questionnaire Core 30 (EORTC QLQ-30) and its breast cancer module, QLQ-BR23. Prespecified exploratory analyses included a longitudinal mixed-effect model comparing treatment arms and a time to definitive clinically meaningful deterioration (TTD) analysis carried out in the global health status/quality of life (GHS/QoL), and all functional and symptom scales from the EORTC QLQ-C30 and -BR23 questionnaires. Between-arm TTD comparisons were made using a stratified log-rank test and a Cox proportional hazards model.. Baseline scores were similar between arms. Statistically significant estimated overall improvement from baseline in GHS/QoL was seen for talazoparib compared with statistically significant deterioration for PCT {3.0 [95% confidence interval (CI) 1.2, 4.8] versus -5.4 [95% CI -8.8, -2.0]; between arms, P < 0.0001}. A statistically significant greater delay was observed in TTD in GHS/QoL, favoring talazoparib over PCT [hazard ratio, 0.38 (95% CI 0.26, 0.55; median, 24.3 versus 6.3 months, respectively; P < 0.0001)]. A statistically significant overall change and a statistically significant delay in TTD, all favoring talazoparib, were also observed in multiple functions and symptoms.. Patients who received talazoparib had significant overall improvements and significant delay in TTD in multiple cancer-related and breast cancer-specific symptoms, functions, and GHS/QoL.. NCT01945775.

Topics: Adult; Aged; Aged, 80 and over; Antineoplastic Combined Chemotherapy Protocols; BRCA1 Protein; BRCA2 Protein; Breast Neoplasms; Female; Germ-Line Mutation; Humans; Middle Aged; Patient Reported Outcome Measures; Phthalazines; Poly(ADP-ribose) Polymerase Inhibitors; Quality of Life; Time Factors; Young Adult

Talazoparib (1 mg/day) exhibited promising efficacy and safety in patients with advanced breast cancer during ABRAZO (NCT02034916); this study evaluated patient-reported outcomes (PROs).. ABRAZO is a two-cohort, two-stage, phase 2 study of talazoparib in patients with advanced breast cancer after a response to prior platinum-based therapy (cohort 1 [C1], n = 49) or ≥3 platinum-free cytotoxic-based regimens (cohort 2 [C2], n = 35). PROs were assessed on day 1 (baseline), every 6 weeks for an initial 24 weeks, and every 12 weeks thereafter until progression, using the European Organisation for Research and Treatment of Cancer Quality of Life Questionnaire Core 30 (QLQ-C30) and its breast cancer module, QLQ-BR23.. Global health status/quality of life (GHS/QoL) was maintained from baseline across all time points for both C1 and C2. For C1 and C2, median time to deterioration (TTD) of GHS/QoL (95% confidence interval [CI]) was 2.8 (2.1, 3.0) and 5.5 (4.2, 5.7) months, respectively. Median TTD for all QLQ-C30 functional scales for C1 and C2 ranged 2.1-3.1 months and 4.2-5.6 months, respectively; median TTD for all QLQ-BR23 symptom scales ranged 2.6-4.0 months and 4.2-5.6 months, respectively. There were no statistically significant differences in estimated overall change from baseline in the GHS/QoL scale for both cohorts (C1: -2.6 [95% CI, -7.8, 2.5]; C2: 1.2 [95% CI, -5.5, 8.0]). Significant overall improvements in the breast symptoms and arm symptoms and the future perspective of patients in C1 and C2 were observed, despite the statistically significant and clinically meaningful overall deterioration among patients regarding their role functioning (in C1) and dyspnoea symptoms (in C2).. Despite the statistically significant and clinically meaningful overall deterioration among patients regarding their role functioning (in C1) and dyspnoea symptoms (in C2), patients in both C1 and C2 reported significant overall improvements in their breast symptoms, arm symptoms and future perspective, and their GHS/QoL was maintained from baseline.

Topics: Antineoplastic Agents; Antineoplastic Combined Chemotherapy Protocols; Breast Neoplasms; Female; Genes, BRCA1; Genes, BRCA2; Germ-Line Mutation; Humans; Middle Aged; Molecular Targeted Therapy; Neoplasm Proteins; Organoplatinum Compounds; Patient Reported Outcome Measures; Phthalazines; Poly(ADP-ribose) Polymerase Inhibitors; Quality of Life; Recombinational DNA Repair; Severity of Illness Index; Symptom Assessment

Talazoparib is a poly (adenosine diphosphate-ribose) polymerase inhibitor approved for the treatment of adult patients with deleterious or suspected deleterious germline BRCA-mutated (gBRCAm), HER2-negative, locally advanced or metastatic breast cancer (LA/mBC), with approval based on the EMBRACA trial. To date, there are no published data on talazoparib use in the real-world United States (USA) setting.. Characteristics, treatment patterns, and clinical outcomes of real-world US patients with gBRCAm HER2-negative LA/mBC treated with talazoparib monotherapy were collected via retrospective chart review and summarized using descriptive statistics.. Among 84 eligible patients, 35.7% had hormone receptor-positive tumors and 64.3% had triple-negative LA/mBC (TNBC). At talazoparib initiation, 29.8% had ECOG PS of ≥2 and 19.0% had brain metastasis. Mutations in gBRCA1 or 2 were detected among 64.3% and 35.7% of patients, respectively. Talazoparib was given as 1st-line therapy in 14.3% of patients, 2nd-line in 40.5%, and 3rd- or 4th-line in 45.2%. Median time to talazoparib treatment failure was 8.5 months (95% CI, 8.0-9.7), median progression-free survival was 8.7 months (95% CI, 8.0-9.9), the median time from initiation to chemotherapy was 12.2 months (95% CI, 10.5-20.1), and the overall response rate was 63.1%. No differences in clinical outcomes were observed between patients with HR-positive/HER2-negative LA/mBC and patients with TNBC by using unadjusted statistical comparisons. Brain metastasis and ECOG PS ≥2 at talazoparib initiation were associated with treatment failure and progression or mortality.. Overall, talazoparib clinical outcomes in this real-world population are consistent with findings from EMBRACA.

Topics: Adult; Brain Neoplasms; Breast Neoplasms; Female; Humans; Retrospective Studies; Triple Negative Breast Neoplasms; United States

Genetic testing is essential to the diagnosis and management of patients with breast cancer. For example, women who carry mutations in BRCA1/2 genes have an increased lifetime risk of breast cancer and the presence of these mutations may sensitize the patient to treatment with poly(ADP-ribose) polymerase (PARP) inhibitors. Two PARP inhibitors are approved by the US Food and Drug Administration for patients with germline BRCA-mutated advanced breast cancer (olaparib and talazoparib). The NCCN Clinical Practice Guidelines in Oncology (NCCN Guidelines) for Breast Cancer (Version 2.2023) recommend that all patients with recurrent or metastatic breast cancer (mBC) be assessed for the presence of germline BRCA1/2 mutations. However, many women eligible for genetic testing do not receive it. Here, we provide our perspectives on both the importance of genetic testing and the challenges patients and community clinicians may face when trying to access genetic testing. We also present a hypothetical case study involving a female patient with germline BRCA-mutated human epidermal growth factor receptor 2 (HER2)-negative mBC to highlight potential clinical considerations on the use of talazoparib, including the decision to initiate therapy, dosing considerations, potential drug-drug interactions, and managing side effects. This case illustrates the benefits of a multidisciplinary approach to managing patients with mBC and involving the patient in the decision-making process. This patient case is fictional and does not represent events or a response from an actual patient; this fictional case is for educational purposes only.

Topics: BRCA1 Protein; BRCA2 Protein; Breast Neoplasms; Female; Genetic Testing; Germ-Line Mutation; Humans

Poly (ADP-ribose) polymerase (PARP) inhibitors provide a promising therapeutic strategy for triple-negative breast cancers (TNBCs) with BRCA1/2 mutation. However, acquire resistance mechanisms and genetic alterations limit the clinical efficacy of PARP inhibitors. The aberrant activation of phosphatidylinositol 3-kinase (PI3K) is a significant problem for cancer development and thus the inhibition of PI3K by PI3K inhibitors is a novel targeted therapy in advanced breast cancer. Here, we, for the first time, investigated that the combined inhibition of PARP by Talazoparib (TAL) and PI3K by LY294002 synergistically inhibited proliferation of BRCA1 mutant HCC1937 TNBC cells through apoptosis, G0/G1 arrest, oxidative stress and increased DNA damage compared to drug alone. Additionally, TAL and LY294002 combination could be a promising strategy for overcoming TAL resistance. Co-treatment of TAL with LY294002 considerably suppressed the activation of PI3K, Akt1 and mTOR expression and phosphorylated protein levels in TNBC cells and caused changes in the multiple kinase phosphorylation. Our findings revealed that the dual inhibition of PARP and PI3K might represent an effective therapeutic strategy for TNBC and potentially overcome TAL resistance.

Topics: BRCA1 Protein; Breast Neoplasms; Cell Line, Tumor; Chromones; Female; Humans; Morpholines; Phosphatidylinositol 3-Kinases; Phthalazines; Poly(ADP-ribose) Polymerase Inhibitors; Triple Negative Breast Neoplasms

PARP inhibitors emerged as clinically effective anti-tumor agents in combination with DNA damaging agents but the toxicity of DNA damaging agents and their off-target effects caused serious problems in cancer therapy. They confer cytotoxicity in cancer cells both by catalytic inhibition and trapping of PARP-1 at the DNA damage site. There is a lack of direct evidence to quantitatively determine the trapped PARP-1 in cellular DNA. Here, we have precisely evaluated the mechanism of PARP trapping mediated anti-cancer action of Quinacrine (QC), BMN-673, and their combination (QC + BMN-673) in breast cancer cells. We introduced a strategy to measure the cellular PARP trapping potentiality of BMN-673 in QC pretreated cells using a fluorescence-based assay system. It was found that QC+ BMN-673 induced apoptosis by triggering DNA damage in breast cancer cells. Treatment with QC + BMN-673 stimulated the expression of PARP-1 in the chromatin compared to that of PARP-2 and PARP-3. QC + BMN-673 treatment also caused a dose-dependent and time-dependent accumulation of PARP-1 and inhibition of PARylation in the chromatin. Upregulation of BER components (pol-β and FEN-1), an unchanged HR and NHEJ pathway proteins, and reduction of luciferase activity of the cells transfected with R-p21-P (LP-BER) were noted in combined drug-treated cells. Interestingly, silencing of pol-β resulted in unchanged PARP-1 trapping and PAR activity in the chromatin with increasing time after QC + BMN-673 treatment without altering APC and FEN-1 expression. Thus, our data suggested that the QC + BMN-673 augmented breast cancer cell death by pol-β mediated repair inhibition primarily through trapping of PARP-1 besides PARP-1 catalytic inhibition.

Topics: Antineoplastic Agents; Apoptosis; Breast Neoplasms; Chromatin; DNA Damage; DNA Repair; Female; Flap Endonucleases; Humans; MCF-7 Cells; Phthalazines; Poly (ADP-Ribose) Polymerase-1; Poly(ADP-ribose) Polymerase Inhibitors; Quinacrine

PARP inhibitors (PARPi) have demonstrated efficacy in tumors with germline breast cancer susceptibility genes (gBRCA) 1 and 2 mutations, but further factors influencing response to PARPi are poorly understood.. Breast cancer tumor tissue from patients with gBRCA1/2 mutations from the phase III EMBRACA trial of the PARPi talazoparib versus chemotherapy was sequenced using FoundationOne CDx.. In the evaluable intent-to-treat population, 96.1% (296/308) had ≥1 tumor BRCA (tBRCA) mutation and there was strong concordance (95.3%) between tBRCA and gBRCA mutational status. Genetic/genomic characteristics including BRCA loss of heterozygosity (LOH; identified in 82.6% of evaluable patients), DNA damage response (DDR) gene mutational burden, and tumor homologous recombination deficiency [assessed by genomic LOH (gLOH)] demonstrated no association with talazoparib efficacy.. Overall, BRCA LOH status, DDR gene mutational burden, and gLOH were not associated with talazoparib efficacy; however, these conclusions are qualified by population heterogeneity and low patient numbers in some subgroups. Further investigation in larger patient populations is warranted.

Topics: BRCA1 Protein; BRCA2 Protein; Breast Neoplasms; Female; Germ Cells; Germ-Line Mutation; Humans; Phthalazines; Poly(ADP-ribose) Polymerase Inhibitors

The efficacy of poly (ADP-ribose) polymerase inhibitors (PARPi) is largely limited to the homologous recombination (HR) deficient cancers. Therefore, there is a necessity to explore novel drug combinations with PARPi to enhance its anti-cancer activity in HR-proficient cancers. By analysing the patient data in cBioPortal, we found copy number amplification of PARP1 in ∼ 22.8% of breast cancers. PARP1 upregulation has been correlated with unfavourable outcome with PARPi treatment. To overcome this adversity, we explored the effect of resveratrol, a natural molecule chemosensitizer, in enhancing the effects of the third generation PARPi, talazoparib (BMN673), against breast adenocarcinoma. Our results show that resveratrol effectively sensitized talazoparib induced cell death in HR proficient and BRCA wild-type breast cancer cells in vitro. Mechanistically, resveratrol caused dysregulation of cell cycle and enhanced talazoparib-induced double strand breaks (DSBs), leading to abnormal mitotic progression culminating in mitotic catastrophe. Intriguingly, our results showed potential of resveratrol in dual-inhibition of AKT-signalling and autophagy flux to impair HR-mediated DSB-repair in breast cancer cells. By using EGFP-LC3 and tf-LC3 (mRFP-EGFP-LC3) expressing breast cancer cells, we found that resveratrol attenuates fusion of autophagosome and lysosome though induction of lysosomal-membrane-permeabilization (LMP). The combination of resveratrol and talazoparib effectively reduced cell proliferation in the high-density cell proliferation assay and also led to tumour volume reduction in vivo pre-clinical SCID-mice model. The combination caused no or minimal cytotoxicity in three different normal cell lines in vitro. Taken together, our work proposes the usage of resveratrol as a chemosensitizer along with talazoparib for targeting HR-proficient breast cancers in clinical settings.

Topics: Animals; Antineoplastic Agents; Autophagy; Breast Neoplasms; Cell Line, Tumor; Female; Humans; Mice; Mice, SCID; Phthalazines; Poly(ADP-ribose) Polymerase Inhibitors; Proto-Oncogene Proteins c-akt; Resveratrol; Xenograft Model Antitumor Assays

The immunological profile of early-stage breast cancer treated with neoadjuvant PARP inhibitors has not been described. The aim of this study was to delineate the changes in the tumor immune microenvironment (TiME) induced by talazoparib.. Patients with operable germline BRCA1/2 pathogenic variant (gBRCA1/2+) breast cancer were enrolled in a feasibility study of neoadjuvant talazoparib. Thirteen patients who received 8 weeks of neoadjuvant talazoparib were available for analysis, including 11 paired pre- and post-talazoparib core biopsies. Treatment-related changes in tumor-infiltrating lymphocytes were examined and immune cell phenotypes and their spatial distribution in the TiME were identified and quantified by multiplex immunofluorescence using a panel of 6 biomarkers (CD3, CD8, CD68, PD-1, PD-L1, and CK).. Neoadjuvant talazoparib significantly increased infiltrating intratumoral and stromal T-cell and cytotoxic T-cell density. There was no difference in PD-1 or PD-L1 immune cell phenotypes in the pre- and post-talazoparib specimens and PD-L1 expression in tumor cells was rare in this cohort. Spatial analysis demonstrated that pre-talazoparib interactions between macrophages and T cells may correlate with pathologic complete response.. This is the first study with phenotyping to characterize the immune response to neoadjuvant talazoparib in patients with gBRCA1/2+ breast cancer. These findings support an emerging role for PARP inhibitors in enhancing tumor immunogenicity. Further investigation of combinatorial strategies is warranted with agents that exploit the immunomodulatory effects of PARP inhibitors on the TiME.

Topics: B7-H1 Antigen; Breast Neoplasms; Female; Fluorescent Antibody Technique; Germ-Line Mutation; Humans; Lymphocytes, Tumor-Infiltrating; Neoadjuvant Therapy; Phthalazines; Pilot Projects; Poly(ADP-ribose) Polymerase Inhibitors; Programmed Cell Death 1 Receptor; Staining and Labeling; Tumor Microenvironment

Tumor cell lines are essential tools in understanding the molecular mechanisms underlying cancer biology and therapeutic responses. Poly (ADP-ribose) polymerase inhibitors (PARPi) kill tumor cells harboring pathogenic mutations of BRCA DNA repair-associated genes 1/2 (BRCA1/2) and are approved to treat ovarian and metastatic breast cancer. Loss of heterozygosity (LOH) of the wild-type BRCA1/2 locus is suspected to increase cellular response to PARPi. To better elucidate the molecular mechanisms underlying PARPi sensitivity and resistance, this study assessed the responses of various pathogenic BRCA1/2-mutant cell lines to the PARPi talazoparib.. Mutant cell lines were extracted and cultured from four surgically resected, human breast cancer specimens with different pathogenic BRCA1/2, one normal breast specimen and one ovarian cancer specimen. Mutation analysis was performed on all cell lines using genomic DNA extraction and polymerase chain reaction. Following treatment with talazoparib, cell growth was assessed using tetrazolium salt and half-maximal inhibitory concentration values were determined.. A partial correlation between different variants of pathogenic BRCA1/2 mutation and talazoparib susceptibility was found, with five of the cell lines exhibiting sensitivity to talazoparib. The most sensitive cell-line to talazoparib had LOH for BRCA1, while the breast cancer cell line harboring BRCA2 LOH was resistant to talazoparib.. This study suggests that LOH does not necessarily correlate with PARPi efficacy. These results lay a foundation for future studies to utilize these novel cell lines to further elucidate the underlying molecular mechanisms of PARPi resistance and reveal new potential drug targets.

Topics: Adenosine Diphosphate; Biomarkers; BRCA1 Protein; BRCA2 Protein; Breast Neoplasms; Female; Humans; Loss of Heterozygosity; Phthalazines; Poly(ADP-ribose) Polymerase Inhibitors; Ribose; Tetrazolium Salts

Topics: Breast Neoplasms; Female; Humans; Phthalazines; Poly(ADP-ribose) Polymerase Inhibitors; Spain

Topics: Breast Neoplasms; Female; Humans; Organizations; Phthalazines; Spain

Topics: BRCA1 Protein; Breast Neoplasms; Germ Cells; Humans; Phthalazines; Poly(ADP-ribose) Polymerase Inhibitors

Poly(ADP-ribose) polymerase inhibitors (PARPi) target tumours defective in homologous recombination (HR). Most BRCA-wild-type (WT) HR-proficient breast cancers are intrinsically resistant to PARP inhibitors, e.g., talazoparib. We evaluated the role of autophagy in this de novo resistance and determined the underlying mechanism to overcome this.. Autophagosome formation and autophagic flux were assessed by evaluating endogenous LC3-II levels and ectopic expression of EGFP-LC3 and mRFP-EGFP-LC3 in breast cancer cells. Autophagy-defective cells were generated by genetic depletion of BECN1, ATG5, p62/SQSTM1 and LAMP1 by using CRISPR-Cas9 double nickase system. The response of PARPi was evaluated in autophagy-proficient and -defective breast cancer cells and in xenograft SCID-mice model.. Pro-survival autophagy was significantly enhanced upon talazoparib treatment in BRCA-WT breast cancer cell lines. Autophagy-deficient cells were hypersensitive to talazoparib. Targeting autophagy synergistically enhanced the therapeutic efficacy of talazoparib in BRCA1-WT breast cancer cells in vitro and in vivo xenograft tumour mouse model. Mechanistically, autophagy inhibition by chloroquine promoted deleterious NHEJ mediated DSB-repair, leading to extensive genomic instability and mitotic catastrophe.. Autophagy confers de novo resistance to PARP inhibitor, talazoparib. Autophagy inhibition improves the therapeutic outcome of PARPi treatment in preclinical mice model, bearing HR-proficient breast tumours, warranting its usage in the clinical settings.

Topics: Animals; Apoptosis; Autophagy; Breast Neoplasms; Cell Proliferation; Drug Resistance, Neoplasm; Female; Gene Expression Regulation, Neoplastic; Homologous Recombination; Humans; Mice; Mice, SCID; Phthalazines; Poly(ADP-ribose) Polymerase Inhibitors; Recombinational DNA Repair; Tumor Cells, Cultured; Xenograft Model Antitumor Assays

Breast cancer is one of the most frequent malignancies. The aim of the article is to analyse the cost-utility ratio and budgetary impact of talazoparib treatment for patients with locally advanced or metastatic gBRCA + breast cancer from the perspective of the Spanish National Health System. Analyses were based on the EMBRACA clinical trial and the model was constructed according to "partitioned survival analysis". Two scenarios were considered in order to compare talazoparib with the alternatives of capecitabine, vinorelbine and eribulin: 1. Chemotherapy in patients pre-treated with anthracyclines/taxanes and, 2. A second- and subsequent-line treatment option. Treatment types following relapse were recorded in the mentioned clinical trial. The effectiveness measure used was quality-adjusted life years (QALY). The average health cost of patients treated at 43 months with talazoparib was 84,360.86€, whilst current treatment costs were 26,683.90€. The effectiveness of talazoparib was 1.93 years of survival (1.09 QALY) relative to 1.58 years (0.83 QALY) in the treatment group. The incremental cost-utility ratio was 252,420.04€/QALY. This represents the additional cost required to earn an additional QALY when changing from regular treatment to talazoparib. Regarding budgetary impact, the number of patients susceptible to receiving treatment with between 94 and 202 talazoparib was estimated, according to scenario and likelihood. The 3-year cost difference was between 6.9 and 9 million euros. The economic evaluation conducted shows an elevated incremental cost-utility ratio and budgetary impact. Taking these results into account, the price of talazoparib would have to be lower than that taken as a reference to reach the cost-utility thresholds.

Topics: Breast Neoplasms; Cost-Benefit Analysis; Female; Humans; Neoplasm Recurrence, Local; Phthalazines; Quality-Adjusted Life Years; Spain

Topics: Bayes Theorem; Breast Neoplasms; Female; Germ Cells; Germ-Line Mutation; Humans; Phthalazines; Piperazines

Topics: BRCA1 Protein; Breast Neoplasms; Germ Cells; Humans; Phthalazines; Poly(ADP-ribose) Polymerase Inhibitors

Two recently approved PARP inhibitors provide an important new therapeutic option for patients with BRCA-mutated metastatic breast cancer. PARP inhibitors significantly prolong progression-free survival in patients, but conventional oral delivery of PARP inhibitors is hindered by limited bioavailability and off-target toxicities, thus compromising the therapeutic benefits and quality of life for patients. Here, we developed a new delivery system, in which the PARP inhibitor Talazoparib is encapsulated in the bilayer of a nano-liposome, to overcome these limitations.

Topics: Animals; Antineoplastic Agents; BRCA1 Protein; BRCA2 Protein; Breast Neoplasms; Drug Compounding; Female; Humans; Immunomodulation; Liposomes; Mammary Neoplasms, Experimental; Mice; Nanoparticles; Phthalazines; Poly(ADP-ribose) Polymerase Inhibitors; Treatment Outcome

Chemoradiation is an effective combined modality therapeutic approach that utilizes principles of spatial cooperation to combat the adaptability associated with cancer and to potentially expand the therapeutic window. Optimal therapeutic efficacy requires intelligent selection and refinement of radiosynergistic pharmaceutical agents, enhanced delivery methods, and temporal consideration. Here, a monodisperse sub-20 nm mixed poloxamer micelle (MPM) system was developed to deliver hydrophobic drugs intravenously, in tandem with ionizing radiation. This report demonstrates in vitro synergy and enhanced radiosensitivity when two molecularly targeted DNA repair inhibitors, talazoparib and buparlisib, are encapsulated and combined with radiation in a 4T1 murine breast cancer model. Evaluation of in vivo biodistribution and toxicity exhibited no reduction in particle accumulation upon radiation and a lack of both acute and chronic toxicities. In vivo efficacy studies suggested the promise of combining talazoparib, buparlisib, and radiation to enhance survival and control tumor growth. Tissue analysis suggests enhanced DNA damage leading to apoptosis, thus increasing efficacy. These findings highlight the challenges associated with utilizing clinically relevant inclusion criteria and treatment protocols because complete tumor regression and extended survival were masked by an aggressively metastasizing model. As with clinical treatment regimens, the findings here establish a need for further optimization of this multimodal platform.

Topics: Aminopyridines; Animals; Breast Neoplasms; Cell Line, Tumor; Chemoradiotherapy; DNA Damage; Female; Humans; Mice; Mice, Inbred BALB C; Micelles; Morpholines; Phthalazines; Xenograft Model Antitumor Assays

Poly-ADP-ribosyl polymerase (PARP) enzymes PARP-1 and PARP-2 recognize DNA damage and set off a cascade of cellular mechanisms required for multiple types of DNA damage repair. PARP inhibitors are small molecule mimetics of nicotinamide which bind to PARP's catalytic domain to inhibit poly-ADP-ribosylation (PARylation) of target proteins, including PARP-1 itself. PARP inhibitors olaparib, veliparib, talazoparib, niraparib and rucaparib have predominantly been studied in women with breast or ovarian cancers associated with deleterious germline mutations in

Topics: Antineoplastic Combined Chemotherapy Protocols; Biomarkers, Tumor; BRCA1 Protein; BRCA2 Protein; Breast Neoplasms; Clinical Trials as Topic; Drug Approval; Female; Humans; Molecular Targeted Therapy; Phthalazines; Poly(ADP-ribose) Polymerase Inhibitors; Treatment Outcome

Topics: Biomarkers, Tumor; BRCA1 Protein; BRCA2 Protein; Breast Neoplasms; Female; Genetic Predisposition to Disease; Health Status; Humans; Mutation; Phthalazines; Poly(ADP-ribose) Polymerase Inhibitors; Progression-Free Survival; Quality of Life; Randomized Controlled Trials as Topic; Time Factors

Topics: Breast Neoplasms; Germ Cells; Humans; Mutation; Phthalazines; Poly(ADP-ribose) Polymerase Inhibitors

: Targeting PARP1 for synthetic lethality is a new strategy for breast cancers harboring germline mutations in BRCA. However, these mutations are rare, and reactivation of BRCA-mediated pathways may result in eventual resistance to PARP1 inhibitor therapy. Alternative synthetic lethality approaches targeting more common sporadic breast cancers and preinvasive ductal carcinoma

Topics: Apoptosis; Breast Neoplasms; Carcinoma, Intraductal, Noninfiltrating; Cell Cycle; Cell Line, Tumor; Chemoprevention; CRISPR-Cas Systems; DNA Breaks, Double-Stranded; DNA Repair; Female; Germ-Line Mutation; HeLa Cells; Humans; Indazoles; Neoplasm Invasiveness; Neoplasm Recurrence, Local; Phthalazines; Piperazines; Piperidines; Poly (ADP-Ribose) Polymerase-1; Poly(ADP-ribose) Polymerase Inhibitors; Spheroids, Cellular; Synthetic Lethal Mutations; X-ray Repair Cross Complementing Protein 1

Poly (ADP-ribose) polymerase 1 (PARP1) is an enzyme involved in DNA repair under investigation as a chemotherapeutic target. Current randomized phase three trials of PARPi in metastatic breast cancer are limited to patients with documented BRCA1/2 mutations and no biomarker of PARPi beyond BRCA status is available. In an effort to identify novel biomarkers for PARP inhibition, we created a cell line (HCC1187/TALRES) resistant to the PARP1 inhibitor talazoparib. Herein we show by array-CGH that HCC1187/TALRES has a selective loss of the proteasome ubiquitin receptor PSMD4 amplicon resulting in significant down-regulation of PSMD4. Conversely, we find that breast cancer cell lines that have copy number gain or amplification for PSMD4 are significantly more sensitive to talazoparib. Functional studies reveal that knock-down of PSMD4 in amplified breast cancer cells and loss of the PSMD4 amplicon result in knock-down of PARP1 protein. We show that PSMD4 is amplified and overexpressed in breast cancer and its overexpression correlates with poor survival. Knock-down of PSMD4 results in a significant decrease in cell growth. We provide evidence that PSMD4 is a proteasomal amplification target in breast cancer that PSMD4 amplification confers sensitivity to PARP inhibition, and that PSMD4 amplification is lost in the process of acquiring resistance to PARPi. Finally, this study shows not only that PSMD4 copy number correlates with PARPi sensitivity, but also, that it may be a better predictor of sensitivity to PARPi than BRCA1/2 mutation.

Topics: Antineoplastic Agents; Biomarkers, Tumor; Breast Neoplasms; Drug Resistance, Neoplasm; Enzyme Inhibitors; Female; Gene Amplification; Humans; MCF-7 Cells; Phthalazines; Poly (ADP-Ribose) Polymerase-1; Proteasome Endopeptidase Complex; RNA-Binding Proteins

Talazoparib, a potent PARP inhibitor, has shown promising clinical and pre-clinical activity by inducing synthetic lethality in cancers with germline

Topics: Animals; BRCA1 Protein; Breast Neoplasms; Cell Line, Tumor; Female; Lactic Acid; Mice; Microscopy, Electron, Scanning; Phthalazines; Polyglycolic Acid; Polylactic Acid-Polyglycolic Acid Copolymer; Xenograft Model Antitumor Assays

PARP1/2 inhibitors are a class of anticancer agents that target tumor-specific defects in DNA repair. Here, we describe BMN 673, a novel, highly potent PARP1/2 inhibitor with favorable metabolic stability, oral bioavailability, and pharmacokinetic properties.. Potency and selectivity of BMN 673 was determined by biochemical assays. Anticancer activity either as a single-agent or in combination with other antitumor agents was evaluated both in vitro and in xenograft cancer models.. BMN 673 is a potent PARP1/2 inhibitor (PARP1 IC50 = 0.57 nmol/L), but it does not inhibit other enzymes that we have tested. BMN 673 exhibits selective antitumor cytotoxicity and elicits DNA repair biomarkers at much lower concentrations than earlier generation PARP1/2 inhibitors (such as olaparib, rucaparib, and veliparib). In vitro, BMN 673 selectively targeted tumor cells with BRCA1, BRCA2, or PTEN gene defects with 20- to more than 200-fold greater potency than existing PARP1/2 inhibitors. BMN 673 is readily orally bioavailable, with more than 40% absolute oral bioavailability in rats when dosed in carboxylmethyl cellulose. Oral administration of BMN 673 elicited remarkable antitumor activity in vivo; xenografted tumors that carry defects in DNA repair due to BRCA mutations or PTEN deficiency were profoundly sensitive to oral BMN 673 treatment at well-tolerated doses in mice. Synergistic or additive antitumor effects were also found when BMN 673 was combined with temozolomide, SN38, or platinum drugs.. BMN 673 is currently in early-phase clinical development and represents a promising PARP1/2 inhibitor with potentially advantageous features in its drug class.

Topics: Animals; Blotting, Western; Breast Neoplasms; Cell Proliferation; DNA Repair-Deficiency Disorders; Drug Resistance, Neoplasm; Female; Flow Cytometry; Humans; Mice; Mice, Nude; Phthalazines; Poly (ADP-Ribose) Polymerase-1; Poly(ADP-ribose) Polymerase Inhibitors; Poly(ADP-ribose) Polymerases; Rats; RNA, Small Interfering; Tumor Cells, Cultured; Tumor Stem Cell Assay; Xenograft Model Antitumor Assays