AZD-7762

AZD-7762 (AZD7762) is a potent and selective inhibitor of Chk1/2 with IC50 of 5 nM; shows less potent against CAM, Yes, Fyn, Lyn, Hck and Lck; enhances the radiosensitivity of mutated p53 tumor cell lines and HT29 xenografts.Solid Tumors, Phase 1 Discontinued (In Vitro) :AZD-7762 (AZD7762) is an equally potent inhibitor of Chk1 and Chk2 in vitro. AZD-7762 potently inhibits Chk1 and Chk2, abrogates DNA damage-induced S and G2 checkpoints, enhances the efficacy of NSC 613327 and SKF 104864A, and modulates downstream checkpoint pathway proteins. AZD-7762 potently inhibits Chk1 phosphorylation of a cdc25C peptide with an IC50 of 5 nM as measured by a scintillation proximity assay. The Ki for AZD-7762 is determined to be 3.6 nM. Kinetic characterization suggests that AZD-7762 binds in the ATP-binding site of Chk1 and is thought to compete directly for ATP binding in a reversible manner. AZD-7762 is shown to abrogate the G2 arrest induced by Camptothecin with an average EC50 of 10 nM (n=12) and maximal abrogation in the range of 100 nM. (In Vivo) :In the rat H460-DNp53 xenograft study, AZD-7762 (AZD7762) potentiates the antitumor activity of NSC 613327 in a dose-dependent manner by a decrease in %T/C with increasing dose (48% and 32%, 10 and 20 mg/kg AZD-7762, respectively) . In the mouse xenograft study in combination with CPT-11, SW620 established tumors are treated with vehicle, CPT-11 alone, AZD-7762 alone, or AZD-7762 in combination with CPT-11. AZD-7762 dosed alone shows insignificant antitumor activity, whereas CPT-11 alone displays striking and significant activity (%T/C with increasing dose is 9 and 1, respectively) . In combination with AZD-7762, %T/C increases significantly to -66% and -67%, respectively. AZD7762 combination with CX-5461 induces cancer cell death of Tp53-null (Tp53-/-) Eμ-Myc lymphoma cells in vitro and in vivo.