AZD0156 (6) monotherapy or sequential treatment with olaparib in TNBC reduced pRAD50 by 34–72%, while post-irinotecan ATM inhibition decreased pRAD50 by 68% in a colorectal cancer xenograft. Combining AZD0156 (6) with temozolomide and irinotecan enhanced antitumor efficacy in vitro and neuroblastoma xenograft models. Combination of AZD0156 and Olaparib has been reported for minor toxicities in Lymphoma. Here, ATM is linked to colorectal cancer.