Pharmacist Medication Insights: Relugolix for Advanced Prostate Cancer

Relugolix (Orgovyx; Myovant Sciences) was approved by the FDA in December 2020 for the treatment of adult patients with advanced prostate cancer.

Relugolix is the first oral drug in this class to receive FDA approval, and it may eliminate some patients’ need to visit the clinic for treatments that require administration by a health care provider. Relugolix is an orally administered treatment that works by blocking the pituitary gland from making luteinizing hormone and follicle-stimulating hormone, which reduces the amount of testosterone the testicles are able to make.

Current treatment options for advanced prostate cancer includes androgen deprivation therapies that are injected or placed as small implants under the skin.

The safety and efficacy of relugolix was evaluated in a randomized, open-label trial in men with advanced prostate cancer. The patients randomly received either relugolix once daily or injections of leuprolide, another hormone-targeting drug, every 3 months for 48 weeks. The objective was to determine whether relugolix achieved and maintained low enough levels of testosterone, by day 29 through end of the treatment course. According to the FDA, in the 622 patients who received relugolix, the castration rate was 96.7%.

The most common adverse effects of relugolix include hot flush, increased glucose, increased triglycerides, musculoskeletal pain, decreased hemoglobin, fatigue, constipation, diarrhea, and increased levels of certain liver enzymes. Androgen deprivation therapies such as relugolix may affect the heart’s electrical properties or cause electrolyte abnormalities. Relugolix can also cause fetal harm and loss of pregnancy when administered to a pregnant female.