A new post hoc analysis of the phase 3 TALAPRO-2 trial found that radiographic progression-free survival (rPFS) strongly correlates with overall survival (OS) in first-line metastatic castration-resistant prostate cancer (mCRPC). The analysis evaluated patients treated with Talazoparib plus Enzalutamide or enzalutamide alone and showed consistent moderate-to-strong correlations across all major patient groups.
The strongest association was observed in the unselected population, with similarly robust findings in homologous recombination repair–deficient and BRCA-mutated subgroups. Researchers also confirmed the correlation regardless of prior exposure to taxane chemotherapy or androgen receptor pathway inhibitors.
Investigators say the findings are clinically important because rPFS events occur much earlier than overall survival events, potentially allowing future prostate cancer trials to produce results faster. The analysis is also the first patient-level validation of the rPFS-to-OS relationship for a PARP inhibitor in first-line mCRPC, supporting the use of rPFS as a meaningful surrogate endpoint for future drug development and regulatory approvals.