A nonsteroidal androgen receptor (AR) antagonist with anti-androgenic and potential antineoplastic activities. AR antagonist BMS-641988 binds to ARs in target tissues and prevents AR activation, which may result in the inhibition of AR-mediated transcriptional activity and tumor cell death in susceptible tumor cell populations. Global gene expression analysis has shown that exposure to this agent may result in a phenotype that is closer to a castration phenotype than is achievable with other antiandrogens such as bicalutamide.