Used in clinical research for evaluating pharmacokinetics and target engagement in studies related to DNA repair pathways, particularly in oncology. Acts as a potent and selective inhibitor of ataxia telangiectasia and Rad3-related (ATR) protein, making it a candidate for combination therapies with DNA-damaging agents such as chemotherapy or radiation. Investigated for its ability to enhance the cytotoxic effects in cancer cells with existing DNA repair deficiencies, especially in tumors with high replication stress. Its application is primarily confined to experimental settings to assess safety, efficacy, and dosing in early-phase trials.