FDA Expands Approval of Talzenna Plus Xtandi for HRR‑Mutated Metastatic Castration‑Sensitive Prostate Cancer

The U.S. Food and Drug Administration on Oct. 26 expanded approval of Pfizer’s TALZENNA, used with XTANDI, for men with metastatic prostate cancer that is still hormone-sensitive, or castration-sensitive, and carries homologous recombination repair, or HRR, gene mutations. The decision moves the regimen into an earlier stage of metastatic disease, before the cancer becomes castration-resistant.

The approval is limited to a biomarker-defined group: patients whose tumors have HRR mutations, including BRCA and non-BRCA alterations, identified by an FDA-authorized test. That makes genetic testing central to use of the regimen. HRR alterations occur in about 25% of metastatic prostate cancers. TALZENNA is a PARP inhibitor, while XTANDI is an androgen-receptor pathway inhibitor.

The expanded indication was backed by the phase 3 TALAPRO-3 trial, which enrolled 599 patients with HRR gene-mutated metastatic androgen-pathway modulation-naive or -sensitive prostate cancer. In the study, talazoparib plus enzalutamide cut the risk of radiographic progression or death by about 52% compared with placebo plus enzalutamide, meeting the trial’s primary endpoint. The hazard ratio was 0.48, with a 95% confidence interval of 0.36 to 0.65, and the result was statistically significant at p less than 0.0001.

At the time of the analysis, median radiographic progression-free survival had not been reached in the TALZENNA-plus-XTANDI group, compared with about 45.8 months in the control arm. Pfizer said the benefit was seen across patients with BRCA and non-BRCA HRR alterations. Overall survival data were still immature.

The results are notable because they push a targeted combination already used in later-stage disease into a setting where patients have newly diagnosed metastatic cancer that has not yet developed resistance to hormone-based treatment. TALAPRO-3 was presented at the 2026 American Society of Clinical Oncology annual meeting and published simultaneously in the New England Journal of Medicine.

Safety was described as consistent with the known profiles of the two drugs, but anemia stood out as a major treatment burden. The most common treatment-emergent adverse events were anemia, fatigue and neutropenia. Pfizer reported grade 3 or higher anemia in 51% of patients treated with the combination, versus 3% in the control arm. Five percent of patients discontinued TALZENNA because of anemia.

In a statement released by Pfizer, Neeraj Agarwal, a prostate cancer specialist and investigator on the study, said the approval “represents a critical advancement for patients with newly diagnosed metastatic prostate cancer with HRR gene mutations,” adding that the findings “reinforc[e] the importance of biomarker testing at the time of diagnosis.”

The combination already had an FDA approval, granted June 20, 2023, for HRR gene-mutated metastatic castration-resistant prostate cancer, or mCRPC. The new action broadens use into an earlier metastatic setting, but not across prostate cancer as a whole. XTANDI is jointly developed and commercialized in the United States by Pfizer and Astellas, while TALZENNA is a Pfizer drug.