S65487 (VOB560) is a potent and selective inhibitor of the anti-apoptotic protein Bcl-2, displaying activity not only against the wild-type protein but also against clinically relevant BCL-2 mutations such as G101V and D103Y. S65487 demonstrates poor affinity toward other Bcl-2 family members, including MCL-1, BFL-1, and BCL-XL, which underlines its selectivity profile. S65487 induces apoptosis in cancer cells and exhibits robust anticancer activities in preclinical studies.