AstraZeneca was developing AZD-7762 for the treatment of solid tumours. AZD-7762 is a potent inhibitor of Chk1 that binds in the ATP binding pocket (IC50 of 5nM; Ki of 3.6nM). AZD-7762 has activity on a range of other kinases {examples with a < 5 fold selectivity included Rous sarcoma oncogene cellular homolog (SRC) family members (e.g., Fgr, Fyn, lymphocyte-specific protein-tyrosine kinase [Lck], and Lyn, but not SRC), Flt1/3, colony stimulating factor receptor (CSF1R), RET, Abelson tyrosine kinase (Abl), and checkpoint kinase 2 (Chk2)}. It is not known if these in vitro kinase inhibitions translate into an effect in vivo. In combination with DNA-damaging agents (gemcitabine, topotecan, doxorubicin, and cisplatin), AZD-7762 inhibits tumour cell growth in vitro with a mode of action that correlates with Chk1 inhibition and abrogation of the Gap 2 (G2) and S phase checkpoints. Rightward shifts in 50% growth inhibition (GI50) values over DNA-damaging agents alone ranged from 5- to 20-fold with gemcitabine demonstrating the largest shifts followed by topotecan. In combination with radiation, AZD-7762 enhances tumour cell growth inhibition and death with survival enhancement ratios ranging from 1.7 to 1.9. Triple combinations with AZD-7762, gemcitabine, and radiation yield the largest survival enhancement ratios. AZD-7762 had been in phase I clinical trials by AstraZeneca for the treatment of solid tumors. However, this study was terminated for the safety reason in 2011.