This study examines if the drug Relugolix, when combined with radiation therapy, can help shrink tumors in prostate cancer patients, particularly when the cancer has spread to a limited number of other body parts (1 to 5). Prostate cancer growth is often fueled by a hormone called testosterone. Relugolix helps by lowering testosterone levels in the body, potentially slowing tumor growth. There are two groups in the study: one gets a placebo (inactive pill) and the other gets Relugolix, both with radiation therapy.

• Participants take pills daily for 180 days and may receive radiation for 1-3 weeks.
• The study requires several follow-up visits over 4 years after treatment ends.
• Participants must meet specific health criteria and agree to use effective birth control during the study.