Pfizer reveals positive phase 3 results for Talzenna combo in prostate cancer

Pfizer has recently announced promising results from a phase 3 study evaluating its prostate cancer treatment combination. The TALAPRO-2 trial has been investigating the effectiveness of Pfizer’s PARP inhibitor, Talzenna (talazoparib), in combination with Xtandi (enzalutamide), an androgen receptor pathway inhibitor developed in partnership with Astellas. This study specifically targeted patients with metastatic castration-resistant prostate cancer (mCRPC).

The results revealed a notable improvement in overall survival (OS) for patients receiving the Talzenna and Xtandi combination compared to those treated with Xtandi alone. This significant advancement was observed not only in the general cohort but also in patients with mCRPC who have homologous recombination repair (HRR) gene mutations.

Roger Dansey, the chief development officer for oncology at Pfizer, highlighted that this combination of a PARP inhibitor with an androgen receptor pathway inhibitor is the first to show a substantial survival benefit in mCRPC patients, regardless of their mutation status. The trial also maintained a previously observed improvement in radiographic progression-free survival in both patient groups. Importantly, the safety profile of the combination therapy remained consistent with the known safety profiles of the individual drugs.

Prostate cancer is one of the most common cancers in men globally, with approximately 1.4 million new cases diagnosed in 2022. Among these, up to 20% develop mCRPC, a severe form of the disease that spreads beyond the prostate gland and progresses despite treatments aimed at lowering testosterone levels. This progression typically occurs within five to seven years following the initial diagnosis.

In June 2023, the US Food and Drug Administration (FDA) approved the use of Talzenna in combination with Xtandi for adults with HRR gene-mutated mCRPC. Following this, the European Commission granted approval in January 2024 for the combination therapy to be used in adults with mCRPC who are not suitable candidates for chemotherapy.

The new data from the TALAPRO-2 trial will be presented to global health authorities to support potential expansions in the use of this combination therapy. Neeraj Agarwal, the global lead investigator for the trial from the Huntsman Cancer Institute at the University of Utah, remarked on the potential impact of these findings. He expressed that the observed results in overall survival could change clinical practices for treating men with mCRPC, which represents the most advanced and aggressive stage of prostate cancer. The TALAPRO-2 results bring a glimmer of hope to patients who face a high unmet need for effective treatment options.