TAS3681

TAS3681 is an orally administered, selective, pure androgen receptor (AR) antagonist developed for the treatment of prostate cancer, particularly castration-resistant prostate cancer (CRPC). Unlike other AR signaling inhibitors such as enzalutamide and abiraterone, which eventually face resistance due to AR mutations, overexpression, or the emergence of constitutively active AR splice variants (AR-Vs), TAS3681 demonstrates a novel dual mechanism of action. It not only antagonizes the full-length androgen receptor but also downregulates both full-length and splice variant forms of AR—including clinically relevant mutants that confer resistance to current therapies. Preclinical studies show that TAS3681 effectively suppresses cell proliferation in AR-overexpressing prostate cancer cells and exhibits strong antitumor efficacy in models resistant to enzalutamide. Clinical trials have confirmed its manageable safety profile and antitumor activity in patients with metastatic CRPC refractory to standard treatments[1][2][3][4][5][6][7][8].