Long-Term Data on Relugolix Combination Therapy for Endometriosis Pain

In "Long-Term Data on Relugolix Combination Therapy for Endometriosis Pain," the panel reviews two-year outcomes from a major open-label extension trial.

The panel reviews the SPIRIT open-label extension program, a two-year study looking at relugolix combination therapy across three types of pain: dysmenorrhea, non-menstrual pelvic pain, and dyspareunia, which was not a primary endpoint. At two years, 85% of patients on relugolix combination therapy met the dysmenorrhea responder definition, meaning at least a 2.8-point decrease on the dysmenorrhea numerical rating scale without an increase in pain medication use; that 2.8-point threshold was set before the study even began. For non-menstrual pelvic pain, 74% of patients met the responder definition, corresponding to a 2.1-point decrease on the same scale, again without an increase in pain medication. Response rates measured at week 52 were sustained through week 104. On safety, the panel notes there were no new safety signals through two years of follow-up; the most frequently reported adverse events were headache, nasopharyngitis, and hot flushes, and very few patients experienced further bone loss. The discussion also touches on the SERINE study, which looked specifically at the contraceptive efficacy of relugolix combination therapy and found it effective, with full data expected to be presented at the American Society for Reproductive Medicine meeting this fall. Elagolix, by contrast, still allows ovulation at both approved doses, though it is less likely at the 200-milligram dose, prompting separate studies pairing it with birth control. Dr. Kho shares her impressions of the SPIRIT trial data, calling it an unusually well-designed study that gives clinicians confidence recommending the combination therapy. The panel stresses setting expectations upfront: meaningful pain reduction doesn't happen in the first week or two, with the greatest improvement typically appearing around 12 weeks, so patients need encouragement to persist that long before judging whether the medication is working for them.

The next episode in this series, "Add-Back Therapy: Balancing Efficacy and Safety in Endometriosis," turns to a second therapy's data on add-back and bone health.