mk-1775 and Neoplasms

DDR (DNA damage response) defects in cells drive tumor formation by promoting DNA mutations, which also provides cancer-specific vulnerabilities that can be targeted by synthetic lethality-based therapies. Until now, PARP inhibitors like olaparib are the first successful case of utilizing synthetic lethality-based therapy to treat cancers with DNA-repairing deficiency (e.g. BRCA1 or BRCA2 mutation), which has fueled the search for more targetable components in the DDR signaling pathway by exploiting synthetic lethality, including but not limited to DNA-PK, ATR, ATM, CHK1, and WEE1. After years of efforts, numerous DDR kinase inhibitors have been discovered. Some of them are being investigated in clinical trials and have shown promising results for cancer therapy. In this review, we summarize the latest advancement in the development of DDR kinase inhibitors including those in preclinical stages and clinical trials, the crystal structures of DDR enzymes, and binding modes of inhibitors with target proteins. The biological functions involving different genes and proteins (ATR, DNA-PK, ATM, PARP, CHK1, and WEE1) are also elucidated.

Topics: DNA Damage; DNA Repair; Humans; Mutation; Neoplasms; Poly(ADP-ribose) Polymerase Inhibitors; Signal Transduction

Polo-like kinase 1 (PLK1) plays an important role in a variety of cellular functions, including the regulation of mitosis, DNA replication, autophagy, and the epithelial-mesenchymal transition (EMT). PLK1 overexpression is often associated with cell proliferation and poor prognosis in cancer patients, making it a promising antitumor target. To date, at least 10 PLK1 inhibitors (PLK1i) have been entered into clinical trials, among which the typical kinase domain (KD) inhibitor BI 6727 (volasertib) was granted "breakthrough therapy designation" by the FDA in 2013. Unfortunately, many other KD inhibitors showed poor specificity, resulting in dose-limiting toxicity, which has greatly impeded their development. Researchers recently discovered many PLK1i with higher selectivity, stronger potency, and better absorption, distribution, metabolism, and elimination (ADME) characteristics. In this review, we emphasize the structure-activity relationships (SARs) of PLK1i, providing insights into new drugs targeting PLK1 for antitumor clinical practice.

Topics: Antineoplastic Agents; Cell Cycle Proteins; Humans; Neoplasms; Polo-Like Kinase 1; Protein Kinase Inhibitors; Protein Serine-Threonine Kinases; Proto-Oncogene Proteins

WEE1 inhibitor has been shown to potential chemotherapy or radiotherapy sensitivity in preclinical models, particularly in p53-mutated or deficient cancer cells although not exclusively. Here, we review the clinical development of WEE1 inhibitor in combination with chemotherapy or radiotherapy with concurrent chemotherapy as well as its combination with different novel agents.. Although several clinical trials have shown that WEE1 inhibitor can be safely combined with different chemotherapy agents as well as radiotherapy with concurrent chemotherapy, its clinical development has been hampered by the higher rate of grade 3 toxicities when added to standard treatments. A few clinical trials had also been conducted to test WEE1 inhibitor using TP53 mutation as a predictive biomarker. However, TP53 mutation has not been shown to be the most reliable predictive biomarker and the benefit of adding WEE1 inhibitor to chemotherapy has been modest, even in TP53 biomarker-driven studies. There are ongoing clinical trials testing WEE1 inhibitor with novel agents such as ATR and PAPR inhibitors as well as anti-PDL1 immunotherapy, which may better define the role of WEE1 inhibitor in the future if any of the novel treatment combination will show superior anti-tumor efficacy with a good safety profile compared to monotherapy and/or standard treatment.

Topics: Antineoplastic Agents; Antineoplastic Combined Chemotherapy Protocols; Cell Cycle; Cell Cycle Proteins; DNA Breaks, Double-Stranded; DNA Replication; Enzyme Inhibitors; Humans; Neoplasms; Protein-Tyrosine Kinases; Pyrazoles; Pyrimidinones

Personalized medicine and therapies represent the goal of modern medicine, as drug discovery strives to move away from one-cure-for-all and makes use of the various targets and biomarkers within differing disease areas. This approach, especially in oncology, is often undermined when the cells make use of alternative survival pathways. As such, acquired resistance is unfortunately common. In order to combat this phenomenon, synthetic lethality is being investigated, making use of existing genetic fragilities within the cancer cell. This Perspective highlights exciting targets within synthetic lethality, (PARP, ATR, ATM, DNA-PKcs, WEE1, CDK12, RAD51, RAD52, and PD-1) and discusses the medicinal chemistry programs being used to interrogate them, the challenges these programs face, and what the future holds for this promising field.

Topics: Ataxia Telangiectasia Mutated Proteins; Cell Cycle Proteins; Cyclin-Dependent Kinases; DNA-Activated Protein Kinase; Genes, BRCA2; Humans; Neoplasms; Poly(ADP-ribose) Polymerases; Precision Medicine; Protein Kinase Inhibitors; Protein-Tyrosine Kinases; Rad51 Recombinase; Synthetic Lethal Mutations

The inhibition of the DNA damage response (DDR) pathway in the treatment of cancer has recently gained interest, and different DDR inhibitors have been developed. Among them, the most promising ones target the WEE1 kinase family, which has a crucial role in cell cycle regulation and DNA damage identification and repair in both nonmalignant and cancer cells. This review recapitulates and discusses the most recent findings on the biological function of WEE1/PKMYT1 during the cell cycle and in the DNA damage repair, with a focus on their dual role as tumor suppressors in nonmalignant cells and pseudo-oncogenes in cancer cells. We here report the available data on the molecular and functional alterations of WEE1/PKMYT1 kinases in both hematological and solid tumors. Moreover, we summarize the preclinical information on 36 chemo/radiotherapy agents, and in particular their effect on cell cycle checkpoints and on the cellular WEE1/PKMYT1-dependent response. Finally, this review outlines the most important pre-clinical and clinical data available on the efficacy of WEE1/PKMYT1 inhibitors in monotherapy and in combination with chemo/radiotherapy agents or with other selective inhibitors currently used or under evaluation for the treatment of cancer patients.

Topics: Antineoplastic Agents; Cell Cycle; Cell Cycle Proteins; Chemoradiotherapy; Disease Progression; DNA Repair; DNA Replication; Drug Resistance, Neoplasm; Drug Synergism; Genomic Instability; Hematologic Neoplasms; Humans; Membrane Proteins; Mitosis; Mutation; Neoplasm Proteins; Neoplasms; Oncogenes; Protein Kinase Inhibitors; Protein Serine-Threonine Kinases; Protein-Tyrosine Kinases; Pyrazoles; Pyrimidinones; Signal Transduction; Tumor Suppressor Proteins

Wee1 kinase controls the G2-M checkpoint. Wee1 inhibition by AZD1775 allows cells with a deregulated G1 checkpoint to progress, resulting in catastrophe and apoptosis. The challenges ahead are in the establishment of the optimum dosing schedule either alone or in combination and the identification of patients with specific biomarker profiles who benefit most.. This article provides an overview of AZD1775, based on English peer-reviewed articles on MEDLINE. The authors highlight the data from the published preclinical and clinical studies.. A majority of the current clinical trials focus on AZD1775 combined with chemotherapy or radiation. Treatment with AZD1775 was tolerated, and antitumor activity has been observed, especially in patients with advanced malignancies harboring G1 checkpoint aberrations and/or DNA damage repair defects. Thus, identification of the molecular subtypes that benefit most from the treatment with AZD1775 alone or in combination may provide a novel strategy for cancer therapy. Research is needed for devising regimens to explore AZD1775 in combination with biologically targeted agents and/or immunotherapy (low dose vs. high dose, intermittent vs. continuous, sequential vs. concurrent, etc.) for identifying potential biomarkers predictive of response and survival.

Topics: Animals; Antineoplastic Agents; Apoptosis; Biomarkers, Tumor; Cell Cycle Proteins; Humans; Neoplasms; Nuclear Proteins; Patient Selection; Protein Kinase Inhibitors; Protein-Tyrosine Kinases; Pyrazoles; Pyrimidines; Pyrimidinones

Cancer cells usually display higher proliferation rates than normal cells. Some currently used antitumor drugs, such as vinca alkaloids and taxanes, act by targeting microtubules and inhibiting mitosis. In the last years, different mitotic regulators have been proposed as drug target candidates for antitumor therapies. In particular, inhibitors of Cdks, Chks, Aurora kinase and Polo-like kinase have been synthesized and evaluated in vitro and in animal models and some of them have reached clinical trials. However, to date, none of these inhibitors has been still approved for use in chemotherapy regimes. We will discuss here the most recent preclinical information on those new antimitotic drugs, as well as the possible molecular bases underlying their lack of clinical efficiency. Also, advances in the identification of other mitosis-related targets will be also summarized.

Topics: Antimitotic Agents; Antineoplastic Agents; Benzamides; Clinical Trials as Topic; Cyclin-Dependent Kinases; Humans; Microtubules; Mitosis; Neoplasm Proteins; Neoplasms; Protein Kinase Inhibitors; Protein Serine-Threonine Kinases; Pyrazoles; Pyrimidines; Pyrimidinones; Quinazolines

Wee1, a protein kinase, regulates the G 2 checkpoint in response to DNA damage. Preclinical studies have elucidated the role of wee1 in DNA damage repair and the stabilization of replication forks, supporting the validity of wee1 inhibition as a viable therapeutic target in cancer. MK-1775, a selective and potent small-molecule inhibitor of wee1, is under clinical development as a potentiator of DNA damage caused by cytotoxic chemotherapies. We present a review of the role of wee1 in the cell cycle and DNA replication and summarize the clinical development to date of this novel class of anticancer agents.

Topics: Antineoplastic Agents; Cell Cycle Proteins; Clinical Trials as Topic; DNA Damage; DNA Repair; G2 Phase Cell Cycle Checkpoints; Humans; Neoplasms; Nuclear Proteins; Protein-Tyrosine Kinases; Pyrazoles; Pyrimidines; Pyrimidinones; RNA Interference

Inducing DNA damage is a well known strategy for attacking cancer, already being used for many years by the application of a variety of anti cancer drugs. Tumor cells and other rapidly dividing cells are more sensitive to DNA damage caused by DNA damaging agents compared to normal cells. While normal cells can rely on various mechanisms for DNA repair in order to protect the integrity of the genome and to promote cell survival, most tumor cells, due to genetic changes, are more challenged when it comes to repair of DNA damage. Wee 1 is a tyrosine kinase that phosphorylates CDC2 at Tyr 15 and as such plays a pivotal role in the G2 DNA damage checkpoint. The strategy of inhibition of Wee 1 by a tyrosine kinase inhibitor is exploiting the impaired options for DNA damage repair especially in cells with deregulated p53, which results in malfunction of the G1 checkpoint. Tumor cells that are unable to rely on the G1 checkpoint are more sensitive to G2 checkpoint abrogation. Administration of DNA damaging chemotherapy in combination with a Wee 1 inhibitor may therefore selectively sensitize p53 deficient cells, while normal cells are spared from toxicity. PD-166285 has been described as a novel G2 abrogator and Wee 1 inhibitor, but has also been characterized as a broad-spectrum receptor tyrosine kinase inhibitor. MK-1775 is a specific and potent inhibitor of Wee-1 and is currently under investigation in a multi-center phase I study in combination with either gemcitabine, carboplatin or cisplatin in patients with advanced solid tumors. Preliminary results show good tolerability and promising anti-cancer activity.

Topics: Animals; Antineoplastic Agents; Antineoplastic Combined Chemotherapy Protocols; Cell Cycle Proteins; DNA Damage; Drug Screening Assays, Antitumor; G2 Phase; Humans; Neoplasms; Nuclear Proteins; Phosphorylation; Protein Kinase Inhibitors; Protein-Tyrosine Kinases; Pyrazoles; Pyridones; Pyrimidines; Pyrimidinones; Tumor Suppressor Protein p53

New anticancer agents are needed in order to overcome the resistance of cancer cells to standard chemotherapy. At present, many of the molecular events that drive the malignant transformation and progression have been identified and there is optimism that the development of agents that specifically target such events will improve treatment outcomes. Cancer cells present common alterations in components of pathways that are involved in the normal cell cycle regulation and in mechanisms of DNA damage repair. Wee1-like protein kinase is a tyrosine kinase with a key role as an inhibitory regulator of the G2/M checkpoint that precedes entry into mitosis. Abrogation of this checkpoint through Wee1 inhibition may result in increased antitumor activity of agents that cause DNA damage such as radiation therapy or some cytotoxic agents. This has been confirmed in preclinical studies and results of clinical studies evaluating a Wee1 inhibitor are awaited to establish its activity in combination with chemotherapy. Here we review the role of Wee1 tyrosine kinase in the control of the G2/M checkpoint and the effects of G2/M checkpoint abrogation through Wee1 inhibition. We present results of preclinical studies with Wee1 inhibitors and the results of the first clinical trial recently reported, evaluating MK-1775, a small-molecule inhibitor of Wee1.

Topics: Animals; Antineoplastic Agents; Cell Cycle; Cell Cycle Proteins; Drug Delivery Systems; Drug Resistance, Neoplasm; Humans; Neoplasms; Nuclear Proteins; Protein Kinase Inhibitors; Protein-Tyrosine Kinases; Pyrazoles; Pyrimidines; Pyrimidinones

Adavosertib selectively inhibits Wee1, which regulates intra-S and G2/M cell-cycle checkpoints. This study investigated dosing schedules for adavosertib monotherapy, determining the maximum tolerated dose (MTD) and recommended Phase II dose (RP2D) in patients with advanced solid tumors.Patients received oral adavosertib qd or bid on a 5/9 schedule (5 days on treatment, 9 days off) in 14-day cycles, or qd on one of two 5/2 schedules (weekly, or for 2 of 3 weeks) in 21-day cycles. Safety, efficacy, and pharmacokinetic analyses were performed.Sixty-two patients (female, 64.5%; median age, 61.5 years; most common primary tumors: lung [24.2%], ovary [21.0%]) received treatment (qd schedules, n = 50; bid schedules, n = 12) for 1.8 months (median). Median time to maximum adavosertib concentration was 2.2-4.1 h; mean half-life was 5-12 h. Adverse events (AEs) caused dose reductions, interruptions and discontinuations in 17 (27.4%), 25 (40.3%) and 4 (6.5%) patients, respectively. Most common grade ≥ 3 AEs were anemia, neutropenia (each n = 9, 14.5%) and diarrhea (n = 8, 12.9%). Seven (11.3%) patients experienced 10 treatment-related serious AEs (pneumonia n = 2 [3.2%], dehydration n = 2 [3.2%], anemia n = 1 [1.6%], febrile neutropenia n = 1 [1.6%], and thrombocytopenia n = 1 [1.6%]). Overall objective response rate was 3.4% (2/58); disease control rate was 48.4% (30/62); median progression-free survival was 2.7 months.MTDs were 125 mg (bid 5/9) and 300 mg (qd 5/9 and 5/2 for 2 of 3 weeks); RP2D was 300 mg (qd 5/2 for 2 of 3 weeks). The safety profile was manageable, acceptable, and generally concordant with the known safety profile.

Topics: Anemia; Female; Humans; Male; Maximum Tolerated Dose; Middle Aged; Neoplasms; Pyrazoles; Pyrimidinones

Adavosertib may alter exposure to substrates of the cytochrome P450 (CYP) family of enzymes. This study assessed its effect on the pharmacokinetics of a cocktail of probe substrates for CYP3A (midazolam), CYP2C19 (omeprazole), and CYP1A2 (caffeine).. Period 1: patients with locally advanced or metastatic solid tumors received 'cocktail': caffeine 200 mg, omeprazole 20 mg, and midazolam 2 mg (single dose); period 2: after 7- to 14-day washout, patients received adavosertib 225 mg twice daily on days 1-3 (five doses), with cocktail on day 3. After cocktail alone or in combination with adavosertib administration, 24-h pharmacokinetic sampling occurred for probe substrates and their respective metabolites paraxanthine, 5-hydroxyomeprazole (5-HO), and 1'-hydroxymidazolam (1'-HM). Safety was assessed throughout.. Of 33 patients (median age 60.0 years, range 41-83) receiving cocktail, 30 received adavosertib. Adavosertib co-administration increased caffeine, omeprazole, and midazolam exposure by 49%, 80%, and 55% (AUC. Adavosertib (225 mg bid) is a weak inhibitor of CYP1A2, CYP2C19, and CYP3A.. GOV: NCT03333824.

Topics: Adult; Aged; Aged, 80 and over; Caffeine; Cytochrome P-450 CYP1A2; Cytochrome P-450 CYP2C19; Cytochrome P-450 CYP3A; Cytochrome P-450 Enzyme System; Drug Interactions; Humans; Midazolam; Middle Aged; Neoplasms; Omeprazole

The Wee1 kinase inhibitor adavosertib abrogates cell-cycle arrest, leading to cell death. Prior testing of twice-daily adavosertib in patients with advanced solid tumors determined the recommended phase II dose (RPh2D). Here, we report results for once-daily adavosertib.. A 3 + 3 dose-escalation design was used, with adavosertib given once daily on days 1 to 5 and 8 to 12 in 21-day cycles. Molecular biomarkers of Wee1 activity, including tyrosine 15-phosphorylated Cdk1/2 (pY15-Cdk), were assessed in paired tumor biopsies. Whole-exome sequencing and RNA sequencing of remaining tumor tissue identified potential predictive biomarkers.. Among the 42 patients enrolled, the most common toxicities were gastrointestinal and hematologic; dose-limiting toxicities were grade 4 hematologic toxicity and grade 3 fatigue. The once-daily RPh2D was 300 mg. Six patients (14%) had confirmed partial responses: four ovarian, two endometrial. Adavosertib plasma exposures were similar to those from twice-daily dosing. On cycle 1 day 8 (pre-dose), tumor pY15-Cdk levels were higher than baseline in four of eight patients, suggesting target rebound during the day 5 to 8 dosing break. One patient who progressed rapidly had a tumor. We determined the once-daily adavosertib RPh2D and observed activity in patients with ovarian or endometrial carcinoma, including two with baseline

Topics: Adult; Aged; Aged, 80 and over; Biomarkers, Tumor; Cell Cycle Proteins; Drug Administration Schedule; Enzyme Inhibitors; Female; Humans; Male; Middle Aged; Neoplasms; Protein-Tyrosine Kinases; Pyrazoles; Pyrimidinones; Treatment Outcome

This trial assessed the utility of applying tumor DNA sequencing to treatment selection for patients with advanced, refractory cancer and somatic mutations in one of four signaling pathways by comparing the efficacy of four study regimens that were either matched to the patient's aberrant pathway (experimental arm) or not matched to that pathway (control arm).. Adult patients with an actionable mutation of interest were randomly assigned 2:1 to receive either (1) a study regimen identified to target the aberrant pathway found in their tumor (veliparib with temozolomide or adavosertib with carboplatin [DNA repair pathway], everolimus [PI3K pathway], or trametinib [RAS/RAF/MEK pathway]), or (2) one of the same four regimens, but chosen from among those not targeting that pathway.. Among 49 patients treated in the experimental arm, the objective response rate was 2% (95% CI, 0% to 10.9%). One of 20 patients (5%) in the experimental trametinib cohort had a partial response. There were no responses in the other cohorts. Although patients and physicians were blinded to the sequencing and random assignment results, a higher pretreatment dropout rate was observed in the control arm (22%) compared with the experimental arm (6%;. Further investigation, better annotation of predictive biomarkers, and the development of more effective agents are necessary to inform treatment decisions in an era of precision cancer medicine. Increasing prevalence of tumor mutation profiling and preference for targeted therapy make it difficult to use a randomized phase II design to evaluate targeted therapy efficacy in an advanced disease setting.

Topics: Adult; Aged; Aged, 80 and over; Antineoplastic Agents; Benzimidazoles; Carboplatin; DNA, Neoplasm; Double-Blind Method; Everolimus; Female; Gene Expression Profiling; Humans; Male; Middle Aged; Molecular Diagnostic Techniques; Neoplasms; Pyrazoles; Pyridones; Pyrimidinones; Temozolomide; Young Adult

The WEE1 inhibitor adavosertib (AZD1775) has been investigated in Western patients.. This open-label Phase Ib study (NCT02341456) investigated the safety, pharmacokinetics, and clinical activity of adavosertib in combination with carboplatin alone or paclitaxel plus carboplatin in Asian patients with advanced solid tumors and defined the recommended Phase II dose.. Adavosertib 175 mg bid for 2.5 days with carboplatin alone or paclitaxel plus carboplatin was considered tolerable. Two patients receiving adavosertib 225 mg bid in combination with paclitaxel plus carboplatin experienced dose-limiting toxicities (grade 4 sepsis; grade 5 acute respiratory distress syndrome); this regimen was not considered tolerable. Grade ≥ 3 adverse events reported most commonly in any cohort included: anemia; decreased white blood cell count; decreased neutrophil count; neutropenia; decreased platelet count; thrombocytopenia; and febrile neutropenia. Exposure to adavosertib, as determined by pharmacokinetic analysis, in Asian patients was higher than that previously seen in Western patients. A partial response occurred in 2/12 evaluable patients (16.7%) at the recommended Phase II dose.. Adavosertib 175 mg bid for 2.5 days was chosen as the recommended Phase II dose in combination with paclitaxel and carboplatin in Asian patients.

Topics: Asian People; Cohort Studies; Enzyme Inhibitors; Female; Humans; Male; Neoplasms; Pyrazoles; Pyrimidinones

To support future dosing recommendations, the effect of food on the pharmacokinetics of adavosertib, a first-in-class, small-molecule reversible inhibitor of WEE1 kinase, was assessed in patients with advanced solid tumors.. In this Phase I, open-label, randomized, two-period, two-sequence crossover study, the pharmacokinetics of a single 300 mg adavosertib dose were investigated in fed versus fasted states.. Compared with the fasted state, a high-fat, high-calorie meal (fed state) decreased adavosertib maximum plasma concentration (C. A high-fat meal did not have a clinically relevant effect on the systemic exposure of adavosertib, suggesting that adavosertib can be administered without regard to meals.

Topics: Administration, Oral; Adult; Aged; Antineoplastic Agents; Biological Availability; Cell Cycle Proteins; Cross-Over Studies; Diet, High-Fat; Female; Food-Drug Interactions; Humans; Male; Middle Aged; Neoplasms; Protein Kinase Inhibitors; Protein-Tyrosine Kinases; Pyrazoles; Pyrimidinones

Wee1 tyrosine kinase phosphorylates and inactivates cyclin-dependent kinase (Cdk) 1/2 in response to DNA damage. AZD1775 is a first-in-class inhibitor of Wee1 kinase with single-agent antitumor activity in preclinical models. We conducted a phase I study of single-agent AZD1775 in adult patients with refractory solid tumors to determine its maximum-tolerated dose (MTD), pharmacokinetics, and modulation of phosphorylated Tyr15-Cdk (pY15-Cdk) and phosphorylated histone H2AX (γH2AX) levels in paired tumor biopsies.. AZD1775 was administered orally twice per day over 2.5 days per week for up to 2 weeks per 21-day cycle (3 + 3 design). At the MTD, paired tumor biopsies were obtained at baseline and after the fifth dose to determine pY15-Cdk and γH2AX levels. Six patients with BRCA-mutant solid tumors were also enrolled at the MTD.. Twenty-five patients were enrolled. The MTD was established as 225 mg twice per day orally over 2.5 days per week for 2 weeks per 21-day cycle. Confirmed partial responses were observed in two patients carrying BRCA mutations: one with head and neck cancer and one with ovarian cancer. Common toxicities were myelosuppression and diarrhea. Dose-limiting toxicities were supraventricular tachyarrhythmia and myelosuppression. Accumulation of drug (t1/2 approximately 11 hours) was observed. Reduction in pY15-Cdk levels (two of five paired biopsies) and increases in γH2AX levels (three of five paired biopsies) were demonstrated.. This is the first report of AZD1775 single-agent activity in patients carrying BRCA mutations. Proof-of-mechanism was demonstrated by target modulation and DNA damage response in paired tumor biopsies.

Topics: Administration, Oral; Adult; Aged; Antineoplastic Agents; Cell Cycle Proteins; Dose-Response Relationship, Drug; Drug Administration Schedule; Female; Humans; Male; Middle Aged; Neoplasms; Nuclear Proteins; Protein Kinase Inhibitors; Protein-Tyrosine Kinases; Pyrazoles; Pyrimidines; Pyrimidinones; Young Adult

Cyclin E (CCNE1) has been proposed as a biomarker of sensitivity to adavosertib, a Wee1 kinase inhibitor, and a mechanism of resistance to HER2-targeted therapy.. Copy number and genomic sequencing data from The Cancer Genome Atlas and MD Anderson Cancer Center databases were analyzed to assess ERBB2 and CCNE1 expression. Molecular characteristics of tumors and patient-derived xenografts (PDX) were assessed by next-generation sequencing, whole-exome sequencing, fluorescent in situ hybridization, and IHC. In vitro, CCNE1 was overexpressed or knocked down in HER2+ cell lines to evaluate drug combination efficacy. In vivo, NSG mice bearing PDXs were subjected to combinatorial therapy with various treatment regimens, followed by tumor growth assessment. Pharmacodynamic markers in PDXs were characterized by IHC and reverse-phase protein array.. Among several ERBB2-amplified cancers, CCNE1 co-amplification was identified (gastric 37%, endometroid 43%, and ovarian serous adenocarcinoma 41%). We hypothesized that adavosertib may enhance activity of HER2 antibody-drug conjugate trastuzumab deruxtecan (T-DXd). In vitro, sensitivity to T-DXd was decreased by cyclin E overexpression and increased by knockdown, and adavosertib was synergistic with topoisomerase I inhibitor DXd. In vivo, the T-DXd + adavosertib combination significantly increased γH2AX and antitumor activity in HER2 low, cyclin E amplified gastroesophageal cancer PDX models and prolonged event-free survival (EFS) in a HER2-overexpressing gastroesophageal cancer model. T-DXd + adavosertib treatment also increased EFS in other HER2-expressing tumor types, including a T-DXd-treated colon cancer model.. We provide rationale for combining T-DXd with adavosertib in HER2-expressing cancers, especially with co-occuring CCNE1 amplifications. See related commentary by Rolfo et al., p. 4317.

Topics: Animals; Camptothecin; Cyclin E; Humans; Immunoconjugates; In Situ Hybridization, Fluorescence; Mice; Neoplasms; Receptor, ErbB-2; Trastuzumab

Adavosertib is a small-molecule, ATP-competitive inhibitor of Wee1 kinase. Molecularly targeted oncology agents have the potential to increase the risk of cardiovascular events, including prolongation of QT interval and associated cardiac arrhythmias. This study investigated the effect of adavosertib on the QTc interval in patients with advanced solid tumors.. Eligible patients were ≥ 18 years of age with advanced solid tumors for which no standard therapy existed. Patients received adavosertib 225 mg twice daily on days 1-2 at 12-h intervals and once on day 3. Patients underwent digital 12-lead electrocardiogram and pharmacokinetic assessments pre-administration and time-matched assessments during the drug administration period. The relationship between maximum plasma drug concentration (C. Twenty-one patients received adavosertib. Concentration-QT modeling of ΔQTcF and the upper limit of the 90% confidence interval corresponding to the geometric mean of C. Adavosertib does not have a clinically important effect on QTc prolongation.. GOV: NCT03333824.

Topics: Antineoplastic Agents; Electrocardiography; Humans; Neoplasms; Pyrazoles; Pyrimidinones

Despite notable advances in utilising PARP inhibitor monotherapy, many cancers are not PARP inhibitor-sensitive or develop treatment resistance. In this work, we show that the two structurally-related sesquiterpene lactones, a 2-bromobenzyloxy derivative of dehydrosantonin (BdS) and alantolactone (ATL) sensitise p53 wildtype, homologous recombination-proficient cancer cells to low-dose treatment with the PARP inhibitor, olaparib. Exposure to combination treatments of olaparib with BdS or ATL induces cell-cycle changes, chromosomal instability, as well as considerable increases in nuclear area. Mechanistically, we uncover that mitotic errors likely depend on oxidative stress elicited by the electrophilic lactone warheads and olaparib-mediated PARP-trapping, culminating in replication stress. Combination treatments exhibit moderately synergistic effects on cell survival, probably attenuated by a p53-mediated, protective cell-cycle arrest in the G2 cell-cycle phase. Indeed, using a WEE1 inhibitor, AZD1775, to inhibit the G2/M cell-cycle checkpoint further decreased cell survival. Around half of all cancers diagnosed retain p53 functionality, and this proportion could be expected to increase with improved diagnostic approaches in the clinic. Utilising sublethal oxidative stress to sensitise p53 wildtype, homologous recombination-proficient cancer cells to low-dose PARP-trapping could therefore serve as the basis for future research into the treatment of cancers currently refractory to PARP inhibition.

Topics: Cell Line, Tumor; Cell Proliferation; Cell Survival; Chromosomal Instability; Dose-Response Relationship, Drug; Drug Synergism; Humans; Lactones; Neoplasms; Oxidative Stress; Phthalazines; Piperazines; Pyrazoles; Pyrimidinones; Sesquiterpenes; Sesquiterpenes, Eudesmane; Tumor Suppressor Protein p53

Topics: Antineoplastic Agents; Cell Cycle Proteins; Cell Survival; Checkpoint Kinase 1; Cyclin-Dependent Kinase Inhibitor p21; Cyclin-Dependent Kinases; DNA Damage; HCT116 Cells; Humans; Neoplasms; Phosphorylation; Protein-Tyrosine Kinases; Pyrazoles; Pyrimidinones; RNA, Small Interfering; S Phase Cell Cycle Checkpoints; Transfection

Topics: A549 Cells; Animals; Cell Cycle Proteins; Cyclin-Dependent Kinase 2; DNA Breaks, Single-Stranded; DNA-Binding Proteins; DNA-Directed DNA Polymerase; DNA, Neoplasm; Drug Resistance, Neoplasm; G2 Phase Cell Cycle Checkpoints; Humans; M Phase Cell Cycle Checkpoints; Mice; Neoplasms; Nuclear Proteins; Protein-Tyrosine Kinases; Pyrazoles; Pyrimidines; Pyrimidinones; Signal Transduction; Tumor Suppressor Protein p53; Ubiquitin-Protein Ligases

Paediatric solid tumours arise from endodermal, ectodermal, or mesodermal lineages. Although the overall survival of children with solid tumours is 75%, that of children with recurrent disease is below 30%. To capture the complexity and diversity of paediatric solid tumours and establish new models of recurrent disease, here we develop a protocol to produce orthotopic patient-derived xenografts at diagnosis, recurrence, and autopsy. Tumour specimens were received from 168 patients, and 67 orthotopic patient-derived xenografts were established for 12 types of cancer. The origins of the patient-derived xenograft tumours were reflected in their gene-expression profiles and epigenomes. Genomic profiling of the tumours, including detailed clonal analysis, was performed to determine whether the clonal population in the xenograft recapitulated the patient's tumour. We identified several drug vulnerabilities and showed that the combination of a WEE1 inhibitor (AZD1775), irinotecan, and vincristine can lead to complete response in multiple rhabdomyosarcoma orthotopic patient-derived xenografts tumours in vivo.

Topics: Animals; Bortezomib; Camptothecin; Cell Cycle Proteins; Child; Clone Cells; Drug Therapy, Combination; Epigenesis, Genetic; Female; Heterografts; High-Throughput Screening Assays; Humans; Hydroxamic Acids; Indoles; Irinotecan; Mice; Neoplasms; Nuclear Proteins; Panobinostat; Protein-Tyrosine Kinases; Pyrazoles; Pyrimidines; Pyrimidinones; Rhabdomyosarcoma; Vincristine; Xenograft Model Antitumor Assays

DNA damage activates Checkpoint kinase 1 (Chk1) to halt cell cycle progression thereby preventing further DNA replication and mitosis until the damage has been repaired. Consequently, Chk1 inhibitors have emerged as promising anticancer therapeutics in combination with DNA damaging drugs, but their single agent activity also provides a novel approach that may be particularly effective in a subset of patients. From analysis of a large panel of cell lines, we demonstrate that 15% are very sensitive to the Chk1 inhibitor MK-8776. Upon inhibition of Chk1, sensitive cells rapidly accumulate DNA double-strand breaks in S phase in a CDK2- and cyclin A-dependent manner. In contrast, resistant cells can continue to grow for at least 7 days despite continued inhibition of Chk1. Resistance can be circumvented by inhibiting Wee1 kinase and thereby directly activating CDK2. Hence, sensitivity to Chk1 inhibition is regulated upstream of CDK2 and correlates with accumulation of CDC25A. We conclude that cells poorly tolerate CDK2 activity in S phase and that a major function of Chk1 is to ensure it remains inactive. Indeed, inhibitors of CDK1 and CDK2 arrest cells in G1 or G2, respectively, but do not prevent progression through S phase demonstrating that neither kinase is required for S phase progression. Inappropriate activation of CDK2 in S phase underlies the sensitivity of a subset of cell lines to Chk1 inhibitors, and this may provide a novel therapeutic opportunity for appropriately stratified patients.

Topics: Antineoplastic Agents; cdc25 Phosphatases; Cell Line, Tumor; Checkpoint Kinase 1; Cyclin A; Cyclin E; Cyclin-Dependent Kinase 2; DNA Breaks, Double-Stranded; Dose-Response Relationship, Drug; Drug Resistance, Neoplasm; Enzyme Activation; Histones; Humans; Molecular Targeted Therapy; Neoplasms; Protein Kinase Inhibitors; Pyrazoles; Pyrimidines; Pyrimidinones; S Phase Cell Cycle Checkpoints; Signal Transduction; Time Factors

Histone H3K36 trimethylation (H3K36me3) is frequently lost in multiple cancer types, identifying it as an important therapeutic target. Here we identify a synthetic lethal interaction in which H3K36me3-deficient cancers are acutely sensitive to WEE1 inhibition. We show that RRM2, a ribonucleotide reductase subunit, is the target of this synthetic lethal interaction. RRM2 is regulated by two pathways here: first, H3K36me3 facilitates RRM2 expression through transcription initiation factor recruitment; second, WEE1 inhibition degrades RRM2 through untimely CDK activation. Therefore, WEE1 inhibition in H3K36me3-deficient cells results in RRM2 reduction, critical dNTP depletion, S-phase arrest, and apoptosis. Accordingly, this synthetic lethality is suppressed by increasing RRM2 expression or inhibiting RRM2 degradation. Finally, we demonstrate that WEE1 inhibitor AZD1775 regresses H3K36me3-deficient tumor xenografts.

Topics: Amino Acid Sequence; Animals; Base Sequence; Blotting, Western; Cell Cycle Proteins; Cell Line, Tumor; Cell Survival; Gene Expression Regulation, Neoplastic; Histone-Lysine N-Methyltransferase; Histones; Humans; Lysine; Methylation; Mice, Inbred BALB C; Mice, Nude; Molecular Sequence Data; Neoplasms; Nuclear Proteins; Nucleotides; Protein-Tyrosine Kinases; Pyrazoles; Pyrimidines; Pyrimidinones; Reverse Transcriptase Polymerase Chain Reaction; Ribonucleoside Diphosphate Reductase; RNA Interference; Sequence Homology, Amino Acid; Sequence Homology, Nucleic Acid; Xenograft Model Antitumor Assays

Inhibition of the DNA damage checkpoint kinase WEE1 potentiates genotoxic chemotherapies by abrogating cell-cycle arrest and proper DNA repair. However, WEE1 is also essential for unperturbed cell division in the absence of extrinsic insult. Here, we investigate the anticancer potential of a WEE1 inhibitor, independent of chemotherapy, and explore a possible cellular context underlying sensitivity to WEE1 inhibition. We show that MK-1775, a potent and selective ATP-competitive inhibitor of WEE1, is cytotoxic across a broad panel of tumor cell lines and induces DNA double-strand breaks. MK-1775-induced DNA damage occurs without added chemotherapy or radiation in S-phase cells and relies on active DNA replication. At tolerated doses, MK-1775 treatment leads to xenograft tumor growth inhibition or regression. To begin addressing potential response markers for MK-1775 monotherapy, we focused on PKMYT1, a kinase functionally related to WEE1. Knockdown of PKMYT1 lowers the EC(50) of MK-1775 by five-fold but has no effect on the cell-based response to other cytotoxic drugs. In addition, knockdown of PKMYT1 increases markers of DNA damage, γH2AX and pCHK1(S345), induced by MK-1775. In a post hoc analysis of 305 cell lines treated with MK-1775, we found that expression of PKMYT1 was below average in 73% of the 33 most sensitive cell lines. Our findings provide rationale for WEE1 inhibition as a potent anticancer therapy independent of a genotoxic partner and suggest that low PKMYT1 expression could serve as an enrichment biomarker for MK-1775 sensitivity.

Topics: Animals; Antineoplastic Agents; Cell Cycle; Cell Cycle Proteins; Cell Line, Tumor; Cell Proliferation; Disease Models, Animal; DNA Damage; Drug Evaluation, Preclinical; Drug Resistance, Neoplasm; Female; Gene Knockdown Techniques; Humans; Membrane Proteins; Mice; Neoplasms; Nuclear Proteins; Protein Kinase Inhibitors; Protein Serine-Threonine Kinases; Protein-Tyrosine Kinases; Pyrazoles; Pyrimidines; Pyrimidinones; Tumor Burden; Xenograft Model Antitumor Assays

Investigate the efficacy and pharmacodynamic effects of MK-1775, a potent Wee1 inhibitor, in both monotherapy and in combination with gemcitabine (GEM) using a panel of p53-deficient and p53 wild-type human pancreatic cancer xenografts.. Nine individual patient-derived pancreatic cancer xenografts (6 with p53-deficient and 3 with p53 wild-type status) from the PancXenoBank collection at Johns Hopkins were treated with MK-1775, GEM, or GEM followed 24 hour later by MK-1775, for 4 weeks. Tumor growth rate/regressions were calculated on day 28. Target modulation was assessed by Western blotting and immunohistochemistry.. MK-1775 treatment led to the inhibition of Wee1 kinase and reduced inhibitory phosphorylation of its substrate Cdc2. MK-1775, when dosed with GEM, abrogated the checkpoint arrest to promote mitotic entry and facilitated tumor cell death as compared to control and GEM-treated tumors. MK-1775 monotherapy did not induce tumor regressions. However, the combination of GEM with MK-1775 produced robust antitumor activity and remarkably enhanced tumor regression response (4.01-fold) compared to GEM treatment in p53-deficient tumors. Tumor regrowth curves plotted after the drug treatment period suggest that the effect of the combination therapy is longer-lasting than that of GEM. None of the agents produced tumor regressions in p53 wild-type xenografts.. These results indicate that MK-1775 selectively synergizes with GEM to achieve tumor regressions, selectively in p53-deficient pancreatic cancer xenografts.

Topics: Animals; Antineoplastic Combined Chemotherapy Protocols; Carcinoma, Pancreatic Ductal; Cell Cycle Proteins; Cell Line, Tumor; Deoxycytidine; Disease Progression; Drug Synergism; Female; Gemcitabine; Genes, p53; Humans; Mice; Mice, Nude; Mutation; Neoplasms; Nuclear Proteins; Pancreatic Neoplasms; Protein Kinase Inhibitors; Protein-Tyrosine Kinases; Pyrazoles; Pyrimidines; Pyrimidinones; Tumor Burden; Xenograft Model Antitumor Assays

Radiotherapy is commonly used to treat a variety of solid tumors. However, improvements in the therapeutic ratio for several disease sites are sorely needed, leading us to assess molecularly targeted therapeutics as radiosensitizers. The aim of this study was to assess the wee1 kinase inhibitor, MK-1775, for its ability to radiosensitize human tumor cells.. Human tumor cells derived from lung, breast, and prostate cancers were tested for radiosensitization by MK-1775 using clonogenic survival assays. Both p53 wild-type and p53-defective lines were included. The ability of MK-1775 to abrogate the radiation-induced G₂ block, thereby allowing cells harboring DNA lesions to prematurely progress into mitosis, was determined using flow cytometry and detection of γ-H2AX foci. The in vivo efficacy of the combination of MK-1775 and radiation was assessed by tumor growth delay experiments using a human lung cancer cell line growing as a xenograft tumor in nude mice.. Clonogenic survival analyses indicated that nanomolar concentrations of MK-1775 radiosensitized p53-defective human lung, breast, and prostate cancer cells but not similar lines with wild-type p53. Consistent with its ability to radiosensitize, MK-1775 abrogated the radiation-induced G₂ block in p53-defective cells but not in p53 wild-type lines. MK-1775 also significantly enhanced the antitumor efficacy of radiation in vivo as shown in tumor growth delay studies, again for p53-defective tumors.. These results indicate that p53-defective human tumor cells are significantly radiosensitized by the potent and selective wee1 kinase inhibitor, MK-1775, in both the in vitro and in vivo settings. Taken together, our findings strongly support the clinical evaluation of MK-1775 in combination with radiation.

Topics: Animals; Antineoplastic Agents; Breast Neoplasms; Cell Cycle Proteins; Cell Line, Tumor; Combined Modality Therapy; Female; G2 Phase Cell Cycle Checkpoints; Humans; Lung Neoplasms; Male; Mice; Mice, Nude; Neoplasms; Nuclear Proteins; Prostatic Neoplasms; Protein Kinase Inhibitors; Protein-Tyrosine Kinases; Pyrazoles; Pyrimidines; Pyrimidinones; Radiation-Sensitizing Agents; Transplantation, Heterologous; Tumor Suppressor Protein p53; Xenograft Model Antitumor Assays

Inhibition of the checkpoint kinase Chk1, both as a monotherapy and in combination with DNA damaging cytotoxics, is a promising therapeutic approach for the treatment of a wide array of human cancers. However, much remains to be elucidated in regard to the patient populations that will respond best to a Chk1 inhibitor and the optimal therapeutics to combine with a Chk1 inhibitor. In an effort to discover sensitizing mutations and novel combination strategies for Chk1 inhibition, an siRNA screen was performed in combination with the selective Chk1 inhibitor AR458323. This screen employed a custom made library of siRNAs targeting 195 genes, most of which are involved in cell-cycle control or DNA damage repair. One of the most prominent and consistent hits across runs of the screen performed in three different cancer cell lines was Wee1 kinase. MK-1775 is a small molecule inhibitor of Wee1 that is currently in early stage clinical trials. In confirmation of the results obtained from the siRNA screen, AR458323 and MK-1775 synergistically inhibited proliferation in multiple cancer cell types. This antiproliferative effect correlated with a synergistic induction of apoptosis. In cellular mechanistic studies, the combination of the two molecules resulted in dramatic decreases in inhibitory phosphorylation of cyclin-dependent kinases, an increase in DNA damage, alterations in cell-cycle profile, and collapse of DNA synthesis. In conclusion, the clinical combination of a Chk1 inhibitor and a Wee1 inhibitor holds promise as an effective treatment strategy for cancer.

Topics: Antineoplastic Agents; Apoptosis; Cell Cycle; Cell Cycle Proteins; Cell Line, Tumor; Cell Proliferation; Checkpoint Kinase 1; DNA Replication; Drug Synergism; Gene Expression Regulation, Neoplastic; HeLa Cells; Humans; Neoplasms; Nuclear Proteins; Phosphorylation; Protein Kinase Inhibitors; Protein Kinases; Protein-Tyrosine Kinases; Pyrazoles; Pyrimidines; Pyrimidinones; RNA, Small Interfering

Wee1 is a tyrosine kinase that phosphorylates and inactivates CDC2 and is involved in G(2) checkpoint signaling. Because p53 is a key regulator in the G(1) checkpoint, p53-deficient tumors rely only on the G(2) checkpoint after DNA damage. Hence, such tumors are selectively sensitized to DNA-damaging agents by Wee1 inhibition. Here, we report the discovery of a potent and selective small-molecule inhibitor of Wee1 kinase, MK-1775. This compound inhibits phosphorylation of CDC2 at Tyr15 (CDC2Y15), a direct substrate of Wee1 kinase in cells. MK-1775 abrogates G(2) DNA damage checkpoint, leading to apoptosis in combination with DNA-damaging chemotherapeutic agents such as gemcitabine, carboplatin, and cisplatin selectively in p53-deficient cells. In vivo, MK-1775 potentiates tumor growth inhibition by these agents, and cotreatment does not significantly increase toxicity. The enhancement of antitumor effect by MK-1775 was well correlated with inhibition of CDC2Y15 phosphorylation in tumor tissue and skin hair follicles. Our data indicate that Wee1 inhibition provides a new approach for treatment of multiple human malignancies.

Topics: Animals; Antineoplastic Combined Chemotherapy Protocols; Apoptosis; CDC2 Protein Kinase; Cell Cycle Proteins; Cell Line, Tumor; Cyclin B; Cyclin-Dependent Kinases; DNA Damage; Drug Synergism; Flow Cytometry; HeLa Cells; Humans; Neoplasms; Nuclear Proteins; Phosphorylation; Protein Kinase Inhibitors; Protein-Tyrosine Kinases; Pyrazoles; Pyrimidines; Pyrimidinones; Rats; Rats, Inbred F344; Rats, Nude; Tumor Suppressor Protein p53; Xenograft Model Antitumor Assays