Testing the Addition of the Drug Relugolix to the Usual Radiation Therapy for Advanced-Stage Prostate Cancer, The NRG Promethean Study

This phase II trial compares the usual treatment of radiation therapy alone to using the study drug, relugolix, plus the usual radiation therapy in patients with castration-sensitive prostate cancer that has spread to limited other parts of the body (oligometastatic). Relugolix is in a class of medications called gonadotropin-releasing hormone (GnRH) receptor antagonists. It works by decreasing the amount of testosterone (a male hormone) produced by the body. It may stop the growth of cancer cells that need testosterone to grow. Radiation therapy uses high-energy x rays or protons to kill tumor cells. The addition of relugolix to the radiation may reduce the chance of oligometastatic prostate cancer spreading further.