Positive OS Results for Talazoparib Plus Enzalutamide Prompt Talazoparib Approval Label Consideration

Positive topline results from the final prespecified overall survival (OS) analysis of the TALAPRO-2 study of talazoparib, an oral poly ADP-ribose polymerase (PARP) inhibitor in combination with enzalutamide, an androgen receptor pathway inhibitor, for metastatic castration-resistant prostate cancer (mCRPC) are to be shared with global health authorities to potentially update the talazoparib approved label.

The phase 3 TALAPRO-2 trial, led by Neeraj Agarwal, MD, FASCO, is a multicenter, randomized, double-blind, placebo-controlled study that enrolled 1,035 unique patients with mCRPC. Patients with castrate testosterone levels were randomized to receive either talazoparib 0.5 mg/day plus enzalutamide 160 mg/day or placebo plus enzalutamide 160 mg/day.

Results showed a statistically significant and clinically meaningful improvement in the final OS in both all-comers (n=399; cohort 1) and those with homologous recombination repair gene-mutated mCRPC (n=399; cohort 2) compared with enzalutamide monotherapy.

At the time of final analysis, clinically meaningful improvement in radiographic progression-free survival rPFS, which was the primary endpoint, was maintained in both cohorts. Secondary endpoints included OS, objective response rate, duration of response, and prostate-specific antigen response.

“Metastatic castration-resistant prostate cancer is the most advanced and aggressive stage of the disease, and the TALAPRO-2 results provide much-needed hope to patients who remain in high unmet need for effective treatment options,” Agarwal noted.