New combination therapy shows promise in advanced prostate cancer

CANCER DIGEST – April 1, 2023 – Preliminary results of a clinical trial shows that a combination of two oral drugs provides a significant improvement in treatment outcomes in men with metastatic prostate cancer.

The results of the TALAPRO-2 phase III clinical trial were presented at the American Society of Clinical Oncology Genitourinary Cancer Symposium held Feb. 16-18 in San Francisco.

Led by Dr. Neeraj Agarwal, of the Huntsman Cancer Institute, Utah, TALAPRO-2 involved 805 men with prostate cancer that had spread to other parts of the body. Patients (n=403) were randomly assigned to treatment with the control treatment of enzalutamide alone, and 402 men were assigned to the combination arm using talazoparib plus enzalutamide.

Talazoparib is a chemotherapy that targets specific enzymes within cancer cells to halt growth. It is made by Pfizer under the name Talzenna®. Enzalutamide is an androgen receptor blocker made by Astellas Pharma, Inc. and Pfizer under the name Xtandi®.

In the trial results reported at the symposium, the combination therapy group showed progression-free survival improved by 37 percent compared to the single medication group. After 25 months there were 70 progression events in the combination group compared to 96 events in the single drug group.

Progression-free survival is the period of time the cancer growth is halted.

The overall response results were similar. In the combination group 74 of 120 (37.5 percent) had a complete response, meaning all signs of cancer were eliminated. That compared to 58 of 132 (18.2 percent) evaluated for complete response in the single drug group.

Overall survival results were not reported as there needs to be longer follow-up.

Dr. Agarwal concluded that all patients benefited from the addition of talazoparib to enzalutamide in first line treatment of metastatic prostate cancer.

Sources: Huntsman Cancer Institute press release, and UroToday.com study summary