This clinical trial is focused on studying a condition known as metastatic castration-resistant prostate cancer. This is a type of prostate cancer that continues to grow and spread even when the amount of testosterone in the body is reduced to very low levels. The study is investigating the effects of a new investigational medicine called PF-06821497, also known as Mevrometostat, in combination with another medication called enzalutamide. Enzalutamide is a treatment that is already used to manage prostate cancer. The purpose of the study is to see if the combination of PF-06821497 and enzalutamide is more effective than enzalutamide with a placebo in slowing down the progression of the cancer.

Participants in the study will be randomly assigned to receive either the combination of PF-06821497 and enzalutamide or enzalutamide with a placebo. The study is designed to be double-blind, meaning neither the participants nor the researchers will know who is receiving the investigational medicine and who is receiving the placebo. This helps ensure that the results are not influenced by expectations about the treatment. The study will last for a period of time, during which participants will take the medications orally in the form of capsules or tablets. Regular check-ups and assessments will be conducted to monitor the participants’ health and the progression of the cancer.

The main goal of the study is to determine if the combination of PF-06821497 and enzalutamide can extend the time before the cancer worsens compared to the use of enzalutamide with a placebo. The study will also look at other outcomes, such as overall survival and the time it takes for the cancer to start growing again. Participants’ experiences with pain and quality of life will also be assessed throughout the study. This research aims to provide valuable information that could lead to improved treatment options for men with metastatic castration-resistant prostate cancer.