Androgen Receptor Signaling Inhibitors for Metastatic Hormone Sensitive Prostate Cancer in Asians: Indirect Comparison.

[BACKGROUND] Androgen receptor signaling inhibitors (ARSI) combined with androgen deprivation therapy (ADT) have demonstrated significant survival benefits in metastatic hormone-sensitive prostate cancer (mHSPC) in several clinical trials. However, data specifically in Asian patients remain limited, with individual subgroup analyses showing trends that did not reach statistical significance. We conducted a pooled analysis to provide additional evidence regarding the efficacy of ARSI plus ADT in Asian patients with mHSPC.

[METHODS] We systematically identified clinical trials reporting overall survival (OS) outcomes for ARSI-based doublet therapy in Asian patients with mHSPC. Individual patient data (IPD) were reconstructed from published Kaplan-Meier curves. Data sources included the TITAN Asian subpopulation analysis, the TITAN Japanese subpopulation, and the LATITUDE Japanese subpopulation. Reconstructed data were validated against original hazard ratios (HR) and curves. Pooled survival analyses were performed for the overall Asian cohort and separately for Japanese patients only.

[RESULTS] A total of 291 reconstructed IPDs were analyzed (146 ARSI plus ADT, 145 placebo plus ADT). In the overall Asian cohort, the 3-year OS was 85.2% with ARSI plus ADT versus 77.6% with placebo plus ADT, representing a 32% reduction in the risk of death (HR = 0.68, 95% CI 0.44-1.03, p = 0.07). In the Japanese subpopulation, 3-year OS was 77.4% versus 72.4%, with a 45% reduction in death risk (HR = 0.55, 95% CI 0.29-1.04, p = 0.07). Neither analysis reached statistical significance.

[CONCLUSION] This exploratory analysis observed a trend toward improved survival with ARSI plus ADT in Asian patients with mHSPC that did not achieve statistical significance. Prospective studies are needed to validate these findings.