Study of Talazoparib With Enzalutamide in Men With DDR Gene Mutated mCSPC

This study is for men aged 18 or older (or 20 in Japan, 19 in South Korea) who have been diagnosed with a specific type of prostate cancer that has spread. To be considered, your cancer must be a particular kind (adenocarcinoma of the prostate) and should have certain changes in its DNA repair (DDR) genes. Doctors will check for these gene changes using blood or tissue samples.

You must already be receiving or start a hormone treatment (like a GnRH agonist or antagonist) before joining, and continue it throughout the study. Your cancer must have spread to bones or other soft tissues, but not just to the lymph nodes in your pelvis. It's also important that you haven't received a strong chemotherapy drug called docetaxel for your advanced prostate cancer in the past.

You should be willing to provide tissue samples for further research, if needed, and a saliva sample to help scientists understand your genetic makeup better. Men with certain conditions, like very poor kidney function or a very widespread type of bone spread seen on scans (called a superscan), would not be able to participate.

If you join this study, it will be divided into several stages: a brief pre-screening to see if you might be suitable, a main screening period to confirm your eligibility, the main treatment period, a safety monitoring period, and a long-term follow-up. You'll be randomly assigned to one of two groups, like flipping a coin. You won't know which group you are in, and your doctors won't know either (this is called 'double-blind').

One group will receive talazoparib capsules plus enzalutamide, and the other group will receive a dummy capsule (placebo) that looks identical to talazoparib, plus enzalutamide. Both talazoparib/placebo and enzalutamide are taken as pills. The dose of talazoparib or the dummy pill will usually be 0.5 mg once a day. If you have some kidney problems, your dose might be adjusted to 0.35 mg once daily. Enzalutamide will be given at 160 mg daily.

Throughout the study, you'll have regular visits for check-ups, blood tests, and scans to monitor your health and how the treatment is working. After you finish the active treatment, your health will continue to be monitored for safety and long-term effects. The total duration of your involvement will depend on how you respond to the treatment and the study's follow-up schedule.