A-1155463 is primarily utilized in research settings as a potent and selective inhibitor of BCL-XL, a protein involved in regulating apoptosis. Its application is significant in cancer studies, where it helps researchers understand the role of BCL-XL in tumor survival and resistance to chemotherapy. By inhibiting BCL-XL, A-1155463 promotes apoptosis in cancer cells, making it a valuable tool for exploring potential therapeutic strategies. Additionally, it is used in preclinical studies to evaluate its efficacy and safety in targeting BCL-XL-dependent cancers, particularly in combination with other anticancer agents. This compound aids in advancing the development of targeted cancer therapies and provides insights into overcoming drug resistance mechanisms.