Pfizer (NYSE: PFE) wins FDA approval to move Talzenna combination into earlier prostate cancer

The FDA has approved Pfizer's Talzenna (talazoparib) with enzalutamide for adults with metastatic prostate cancer that is androgen pathway modulation-naïve or -sensitive and carries homologous recombination repair (HRR) gene mutations. Eligible patients must be identified with an FDA-authorised test. The combination was previously approved in June 2023 for HRR-mutated castration-resistant disease.

The decision rests on TALAPRO-3, a double-blind trial that randomised 599 patients with HRR-mutated disease to enzalutamide plus either talazoparib or placebo, alongside continuous androgen deprivation therapy. The hazard ratio for investigator-assessed radiographic progression-free survival was 0.48 (95% CI 0.36 to 0.65). Median radiographic progression-free survival had not been reached with the combination, compared with 45.8 months in the control arm.

Overall survival data were immature at the time of the analysis, and the FDA reported no survival result. A delay in radiographic progression is a meaningful benefit, but it is not the same as a demonstrated extension of life. The label carries warnings for myelodysplastic syndrome and acute myeloid leukaemia, myelosuppression and embryo-fetal toxicity, which matter more when treatment starts earlier and may run for longer.

The review used priority review and Project Orbis, with Australian and Canadian assessments ongoing. Commercially, the approval depends on genetic testing: Pfizer has said up to 30% of patients with metastatic castration-sensitive prostate cancer harbour HRR alterations, but the eligible population will be shaped by how consistently such testing is done in practice. Payers will also weigh the cost of combining two branded medicines over a potentially long treatment period, a question that will grow more pressing as survival data mature.

Sources: FDA approval notice, 26 October; Pfizer priority review announcement, 22 July.