Apalutamide plus ADT shows favorable survival trends in Asian and Japanese mCSPC patients

BACKGROUND: The phase 3 TITAN trial revealed that apalutamide plus androgen deprivation therapy (ADT) has significantly improved outcomes in patients with metastatic castration-sensitive prostate cancer (mCSPC). However, the generalizability of these results to Asian and Japanese populations remains unclear. Bayesian methods provide a probabilistic framework offering more clinically meaningful estimates of benefit in such subpopulations. METHODS: We conducted a Bayesian post hoc analysis using reconstructed individual patient data from the published Asian (n = 221) and Japanese (n = 51) TITAN trial subpopulations. Bayesian Cox proportional hazards models were fitted under four prespecified priors representing different skepticism levels. Posterior median hazard ratios (HRs), 95% credible intervals (CrIs), and probabilities of any benefit (Pr[HR < 1.0]) or substantial benefit (Pr[HR < 0.8]) were calculated. RESULTS: The posterior median HR under the neutral prior for overall survival in the Asian cohort was 0.71 (95% CrI 0.44-1.14), with Pr[HR < 1.0] = 92% and Pr[HR < 0.8] = 69%. Probabilities exceeded 95% under more informative priors. The Japanese cohort demonstrated more pronounced effects (neutral prior HR: 0.55, 95% CrI: 0.22-1.35) with ≥90% probability of benefit across all priors. Posterior median HRs for TTmCRPC were 0.32-0.35 across priors, with ~100% probability of treatment benefit in both cohorts. CONCLUSION: This analysis provides strengthened evidence that apalutamide plus ADT offers meaningful clinical benefit for Asian patients with mCSPC. Moreover, our findings support more informed and individualized clinical decision-making, helping clinicians communicate expected outcomes more clearly during shared decision-making.