AZD7762

AZD7762 is a novel ATP competitive inhibitor of checkpoint kinases. Chk family checkpoint kinases include Chk1 and Chk2. They are activated in response to DNA damage and phosphorylate CDC25A, CDC25C protein phosphatases, which delay cell cycle progression. Therefore, Chk activation initiates cell cycle checkpoint, causes cell cycle arrest, and allows DNA repair.

AZD7762 is a potent selective inhibitor of Chk1. It binds to the ATP binding pocket and compete ATP binding in a reversible manner. AZD7762 inhibits Chk1 phosphorylation of CDC25C peptide with an IC50 of 5 nM. The Ki is 3.6 nM. It is equally potent against Chk2 but less potent against CAM, Yes, Fyn, Lyn, Hck and Lck. [1]

AZD7762 prevents cell cycle arrest and DNA repair in DNA damaged tumor cells, causing tumor cell apoptosis. Hence, it potentiates the antitumor activity of DNA damaging agents and can be used as a chemosensitizing agent. [2]

Half life of AZD7762 is 1-2 hours in mice [3]

References:
[1]Zabludoff SD, et al. AZD7762, a novel checkpoint kinase inhibitor, drives checkpoint abrogation and potentiates DNA-targeted therapies. Mol Cancer Ther, 2008, 7(9): 2955-2966.
[2]Landau HJ, et al. The checkpoint kinase inhibitor AZD7762 potentiates chemotherapy-induced apoptosis of p53-mutated multiple myeloma cells. Mol Cancer Ther. 2012, 11(8): 1781-1788
[3]Goteti K, et al. Preclinical pharmacokinetic/pharmacodynamic models to predict synergistic effects of co-administered anti-cancer agents. Cancer Chemother Pharmacol. 2010, 66(2): 245-254.

Birinapant (TL32711) Improves Responses to GEM/AZD7762 Combination Therapy in Triple-negative Breast Cancer Cell Lines.[Pubmed:27272773]

Anticancer Res. 2016 Jun;36(6):2649-57.

BACKGROUND: Triple-negative breast cancer (TNBC) is an aggressive form of breast cancer currently lacking targeted therapies. Our previous work demonstrated a therapeutic synergism with gemcitabine (GEM) and the CHK1 inhibitor (AZD7762) combination treatment in a TNBC cell line. We hypothesized that the response to this combination therapy would differ among heterogeneous TNBC patients and that addition of a SMAC mimetic (TL32711) could improve efficacy. MATERIALS AND METHODS: Therapeutic responses to GEM, GEM/AZD7762, and GEM/AZD7762/TL32711 combinations were investigated by XTT assays and western blotting of cell cycle and apoptosis-related proteins in ten TNBC cell lines. RESULTS: TNBC cell lines harboring low levels of endogenous CHK1, cIAP1 and cIAP2 were responsive to GEM alone, whereas cell lines demonstrating a minimal increase in phospho-S345 CHK1 after treatment were responsive to GEM/AZD7762 or GEM/AZD7762/TL32711 combination. CONCLUSION: The response of TNBC cells to particular therapies varies and will require development of predictive biomarkers.

Suppression of the metastatic spread of breast cancer by DN10764 (AZD7762)-mediated inhibition of AXL signaling.[Pubmed:27829217]

Oncotarget. 2016 Dec 13;7(50):83308-83318.

Breast cancer is the most common malignant disease occurring in women and represents a substantial proportion of the global cancer burden. In these patients, metastasis but not the primary tumor is the main cause of breast cancer-related deaths. Here, we report the novel finding that DN10764 (AZD7762, a selective inhibitor of checkpoint kinases 1 and 2) can suppress breast cancer metastasis. In breast cancer cells, DN10764 inhibited cell proliferation and GAS6-mediated AXL signaling, consequently resulting in suppressed migration and invasion. In addition, DN10764 induced caspase 3/7-mediated apoptosis in breast cancer cells and inhibited tube formation of human umbilical vein endothelial cells. Finally, DN10764 significantly suppressed the tumor growth and metastasis of breast cancer cells in in vivo metastasis models. Taken together, these data suggest that therapeutic strategies targeting AXL in combination with systemic therapies could improve responses to anti-cancer therapies and reduce breast cancer recurrence and metastases.

Phase I dose-escalation study of AZD7762, a checkpoint kinase inhibitor, in combination with gemcitabine in US patients with advanced solid tumors.[Pubmed:24448638]

Cancer Chemother Pharmacol. 2014 Mar;73(3):539-49.

PURPOSE: AZD7762 is a Chk1 kinase inhibitor which increases sensitivity to DNA-damaging agents, including gemcitabine. We evaluated the safety of AZD7762 monotherapy and with gemcitabine in advanced solid tumor patients. EXPERIMENTAL DESIGN: In this Phase I study, patients received intravenous AZD7762 on days 1 and 8 of a 14-day run-in cycle (cycle 0; AZD7762 monotherapy), followed by AZD7762 plus gemcitabine 750-1,000 mg/m(2) on days 1 and 8, every 21 days, in ascending AZD7762 doses (cycle 1; combination therapy). RESULTS: Forty-two patients received AZD7762 6 mg (n = 9), 9 mg (n = 3), 14 mg (n = 6), 21 mg (n = 3), 30 mg (n = 7), 32 mg (n = 6), and 40 mg (n = 8), in combination with gemcitabine. Common adverse events (AEs) were fatigue [41 % (17/42) patients], neutropenia/leukopenia [36 % (15/42) patients], anemia/Hb decrease [29 % (12/42) patients] and nausea, pyrexia and alanine aminotransferase/aspartate aminotransferase increase [26 % (11/42) patients each]. Grade >/=3 AEs occurred in 19 and 52 % of patients in cycles 0 and 1, respectively. Cardiac dose-limiting toxicities occurred in two patients (both AZD7762 monotherapy): grade 3 troponin I increase (32 mg) and grade 3 myocardial ischemia with chest pain, electrocardiogram changes, decreased left ventricular ejection fraction, and increased troponin I (40 mg). AZD7762 exposure increased linearly. Gemcitabine did not affect AZD7762 pharmacokinetics. Two non-small-cell lung cancer patients achieved partial tumor responses (AZD7762 6 mg/gemcitabine 750 mg/m(2) and AZD7762 9 mg cohort). CONCLUSIONS: The maximum-tolerated dose of AZD7762 in combination with gemcitabine 1,000 mg/m(2) was 30 mg. Although development of AZD7762 is not going forward owing to unpredictable cardiac toxicity, Chk1 remains an important therapeutic target.

Checkpoint kinase inhibitor AZD7762 strongly sensitises urothelial carcinoma cells to gemcitabine.[Pubmed:28049532]

J Exp Clin Cancer Res. 2017 Jan 3;36(1):1.

BACKGROUND: More effective chemotherapies are urgently needed for bladder cancer, a major cause of morbidity and mortality worldwide. We therefore explored the efficacy of the combination of gemcitabine and AZD7762, a checkpoint kinase 1/2 (CHK1/2) inhibitor, for bladder cancer. METHODS: Viability, clonogenicity, cell cycle distribution and apoptosis were assessed in urothelial cancer cell lines and various non-malignant urothelial cells treated with gemcitabine and AZD7762. DNA damage was assessed by gammaH2A.X and 53-BP1 staining and checkpoint activation was followed by Western blotting. Pharmacological inhibition of CHK1 and CHK2 was compared to downregulation of either CHK1 or CHK2 using siRNAs. RESULTS: Combined use of gemcitabine and AZD7762 synergistically reduced urothelial carcinoma cell viability and colony formation relative to either single treatment. Non-malignant urothelial cells were substantially less sensitive to this drug combination. Gemcitabine plus AZD7762 inhibited cell cycle progression causing cell accumulation in S-phase. Moreover, the combination induced pronounced levels of apoptosis as indicated by an increase in the fraction of sub-G1 cells, in the levels of cleaved PARP, and in caspase 3/7 activity. Mechanistic investigations showed that AZD7762 treatment inhibited the repair of gemcitabine-induced double strand breaks by interference with CHK1, since siRNA-mediated depletion of CHK1 but not of CHK2 mimicked the effects of AZD7762. CONCLUSIONS: AZD7762 enhanced sensitivity of urothelial carcinoma cells to gemcitabine by inhibiting DNA repair and disturbing checkpoints. Combining gemcitabine with CHK1 inhibition holds promise for urothelial cancer therapy.