Relugolix in Combination With Radiation Therapy for Treating Patients With High Risk Prostate Cancer

This phase II trial evaluates the best duration for relugolix to be given in combination with radiation therapy when treating patients with high risk prostate cancer. Prostate cancer is a hormonal influenced cancer. Part of the usual treatment for patients with prostate cancer is androgen deprivation therapy (ADT). ADT is used to lower the amount of testosterone in the body, because testosterone appears to help prostate cancer grow. Relugolix works to reduce testosterone levels, which may inhibit proliferation of prostate cancer cells. It is approved by the Food and Drug Administration to treat prostate cancer. Adding relugolix to standard radiation therapy might work better and have fewer side effects than prior forms of hormonal therapy, but the optimal duration of relugolix in combination with radiation is not known.