The TALAPRO-3 study design: a plain language summary.

This summary is about the ongoing research study called TALAPRO-3. This study is testing the use of two medicines called talazoparib and enzalutamide. The two medicines are being used together as a treatment for patients with a type of cancer called metastatic castration-sensitive prostate cancer and changes in specific DNA repair genes within their tumors. The study began in May 2021, and includes 599 patients from 27 countries. Metastatic castration-sensitive prostate cancer is known as mCSPC for short. It is cancer that has started in the prostate and spread to other body parts. The prostate is a gland below the bladder and helps make semen (the liquid that contains sperm). Castration-sensitive means that the cancer responds to treatments that lower testosterone in the blood. In this study, some patients will take talazoparib plus enzalutamide while others will take a placebo plus enzalutamide. Talazoparib and enzalutamide are two different cancer medicines. Talazoparib is not currently used to treat patients with mCSPC. Enzalutamide is used to treat patients with prostate cancer. Talazoparib plus enzalutamide is being compared with a placebo plus enzalutamide to see if patients live longer without their cancer getting worse, or them dying, when taking talazoparib plus enzalutamide or when taking a placebo plus enzalutamide. This study aims to find out if treatment with talazoparib plus enzalutamide increases the length of time the patients in the study live without their cancer getting worse, or them dying, compared with treatment with a placebo plus enzalutamide. The study will also measure how long the patients in the study live, the number and types of side effects they have, their general health and quality of life, and whether there are changes in how patients report their pain.