NEW YORK, July 22, 2026
Pfizer Inc. announced that the U.S. Food and Drug Administration (FDA) has granted Priority Review to its supplemental New Drug Application (sNDA) seeking to expand the use of TALZENNA® (talazoparib) in combination with XTANDI® (enzalutamide) for the treatment of men with homologous recombination repair (HRR) gene-mutated metastatic castration-sensitive prostate cancer (mCSPC). The FDA has assigned a Prescription Drug User Fee Act (PDUFA) target action date in the fourth quarter of 2026. If approved, the combination would move into an earlier stage of metastatic prostate cancer, expanding beyond its current U.S. indication for HRR gene-mutated metastatic castration-resistant prostate cancer (mCRPC). The regulatory submission is supported by positive Phase 3 TALAPRO-3 clinical trial data demonstrating significant improvements in patient outcomes.
Phase 3 TALAPRO-3 Trial Demonstrated Significant Clinical Benefit
The Phase 3 TALAPRO-3 study enrolled 599 patients with HRR gene-altered mCSPC and evaluated TALZENNA plus XTANDI against placebo plus XTANDI in a randomized, double-blind, placebo-controlled setting. The trial met its primary endpoint by showing a 52% reduction in the risk of radiographic disease progression or death, representing a substantial improvement in radiographic progression-free survival (rPFS). Clinical benefits were consistently observed across patients carrying both BRCA and non-BRCA HRR gene alterations, reinforcing the broad potential of the treatment combination. The safety profile remained consistent with the known characteristics of both medicines, with no new safety signals identified during the study. The findings were presented at the 2026 American Society of Clinical Oncology (ASCO) Annual Meeting and simultaneously published in The New England Journal of Medicine, strengthening the scientific evidence supporting the regulatory application.
Potential Expansion for Earlier Treatment of HRR-Mutated Prostate Cancer
According to Pfizer, treating patients during the metastatic castration-sensitive stage offers an important opportunity to delay disease progression before prostate cancer becomes resistant to hormone therapy. Approximately 5–10% of newly diagnosed prostate cancer cases present as mCSPC, while nearly 30% of these patients harbor HRR gene alterations, making biomarker testing increasingly important for selecting targeted therapies. TALZENNA, an oral PARP inhibitor, works by blocking DNA repair mechanisms in cancer cells, while XTANDI, an androgen receptor pathway inhibitor, suppresses androgen signaling that drives prostate cancer growth. Together, the combination targets complementary biological pathways that may provide prolonged disease control in genetically defined patient populations. The application is also under regulatory review by the European Medicines Agency (EMA), while the combination is already approved for HRR gene-mutated mCRPC in more than 60 countries worldwide.
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Pfizer Strengthens Precision Oncology Strategy
The Priority Review marks another milestone in Pfizer’s oncology pipeline, which continues to focus on delivering precision medicines supported by biomarker-driven clinical development. The company believes expanding TALZENNA plus XTANDI into earlier-stage metastatic prostate cancer could provide physicians with an additional targeted treatment option capable of delaying disease progression while emphasizing the growing role of genomic testing in treatment selection. Beyond prostate cancer, TALZENNA is also approved as a single-agent therapy for patients with germline BRCA-mutated HER2-negative advanced or metastatic breast cancer, demonstrating its broader role in precision oncology. If approved later this year, the expanded indication would further strengthen Pfizer’s portfolio of targeted cancer therapies and potentially improve outcomes for men with HRR-mutated metastatic castration-sensitive prostate cancer, where significant unmet medical need remains despite advances in hormone-based therapies.
Source: Pfizer Inc press release
