Choosing Between Newer GnRH Antagonist Therapies for Endometriosis

In "Choosing Between Newer GnRH Antagonist Therapies for Endometriosis," Dr. Davitt compares two newer, FDA-approved options for treating endometriosis-associated pain.

Dr. Davitt compares two newer FDA-approved therapies for endometriosis-associated pain, both studied for dysmenorrhea and non-menstrual pelvic pain. He says he currently uses relugolix more often in his practice, largely because its once-daily dosing is easier for patients to adopt. The particular relugolix formulation he prescribes includes built-in add-back therapy, and he has found patients report fewer side effects and easier tolerability on it; that formulation can be used for up to two years. He has also used elagolix, which comes in a 150-milligram and a 200-milligram dose that can be used for two years and six months, respectively. He says elagolix has also been effective for some patients, though he has received feedback that its more frequent dosing and shorter approved treatment duration can be a concern. He raises those tradeoffs with patients at the very start of treatment, along with a plan for managing side effects and criteria for eventually discontinuing therapy. Dr. Kho adds that this generation of GnRH antagonists represents a major breakthrough compared with older injectable GnRH agonists, which stay in a patient's system for an extended period and can worry patients about medical menopause or worsening mood without an easy way to reverse course. The panel clarifies that elagolix is a monotherapy without a black box warning, making it a fit for patients with estrogen or progesterone contraindications, while the relugolix combination includes a small amount of hormone replacement to offset vasomotor symptoms and bone loss but carries a black box warning. Dr. Davitt then explains the concept behind tailored add-back therapy: because estrogen-responsive tissues vary in sensitivity throughout the body, add-back is designed to limit estrogen reaching endometriosis tissue while still supplying enough estrogen systemically to protect bone mineral density.

In "Long-Term Data on Relugolix Combination Therapy for Endometriosis Pain," the panel reviews long-term trial data behind one of these therapies in detail.