Objective: To evaluate the efficacy and safety of enzalutamide plus androgen deprivation therapy in Japanese men with metastatic hormone-sensitive prostate cancer.
Methods: A post-hoc analysis of the Japanese subgroup in the phase III, randomized, multinational ARCHES study (NCT02677896) was carried out. Patients with metastatic hormone-sensitive prostate cancer were randomized to receive enzalutamide or a placebo, plus androgen deprivation therapy, stratified by disease volume and prior docetaxel therapy. The primary end-point was radiographic progression-free survival. Secondary end-points included time to prostate-specific antigen progression and overall survival.
Results: Of 1150 patients, 92 Japanese patients were randomized to enzalutamide (n = 36) or a placebo (n = 56), plus androgen deprivation therapy; none received prior docetaxel. Enzalutamide plus androgen deprivation therapy reduced the risk of radiographic progression or death in Japanese patients by 61% versus the placebo, similar to the overall population. Similar results were observed with secondary end-points, showing clinical benefit of enzalutamide plus androgen deprivation therapy in Japanese patients. Overall survival data were immature. Grade 3-4 adverse events were reported in 47% and 25% of the enzalutamide and placebo groups, respectively. Nasopharyngitis, hypertension and abnormal hepatic function were reported more frequently in Japanese patients versus the overall population.
Conclusions: Enzalutamide plus androgen deprivation therapy has clinical benefit with a tolerable safety profile in Japanese men with metastatic hormone-sensitive prostate cancer, consistent with the overall population.
Keywords: Japan; androgen receptor antagonists; enzalutamide; metastatic prostate cancer.
© 2021 The Authors. International Journal of Urology published by John Wiley & Sons Australia, Ltd on behalf of the Japanese Urological Association.