Real‐World Comparative Study of Apalutamide Versus Bicalutamide in Combination With Androgen Deprivation Therapy for Metastatic Hormone‐Sensitive Prostate Cancer

OBJECTIVES: To evaluate the real-world effectiveness and safety of apalutamide versus bicalutamide in combination with androgen deprivation therapy (ADT) for metastatic hormone-sensitive prostate cancer (mHSPC) in Japanese clinical practice. METHODS: This multicenter retrospective study analyzed 477 patients with mHSPC who received either apalutamide (n = 102) or bicalutamide (n = 375) in combination with ADT across 19 Japanese institutions. The primary outcome was time to castration-resistant prostate cancer (CRPC). Secondary outcomes included overall survival (OS), prostate-specific antigen (PSA) response, and adverse events. RESULTS: The apalutamide group showed significantly higher CRPC-free probability at 24 months (68.2% vs. 39.8%, p < 0.001) compared to the bicalutamide group. While OS was similar between groups, the apalutamide group demonstrated superior PSA response at 3 months (median PSA: 0.8 vs. 3.4 ng/mL) and lower requirement for secondary treatment (36.3% vs. 53.9%, p = 0.002). Adverse events were more frequent in the apalutamide group (30.4% vs. 4.3%, p < 0.001), particularly rash (15.7% vs. 0.3%, p < 0.001). CONCLUSIONS: In real-world Japanese clinical practice, apalutamide demonstrated superior efficacy in delaying progression to CRPC compared to bicalutamide when combined with ADT for mHSPC, with manageable safety profiles.