Relugolix Combination Therapy long term effective, convenient, and well-tolerated medical treatment for endometriosis: Study

A new long-term extension (LTE) study revealed promising results for the treatment of moderate to severe endometriosis-associated pain using relugolix combination therapy (CT). This open-label, single-arm study published in the Human Reproduction journal extended over two years to underline the significant improvements in pain management and overall quality of life for women with this chronic condition.

Endometriosis is characterized by dysmenorrhea, non-menstrual pelvic pain (NMPP) and dyspareunia with a substantial impact on the lives of affected women. The SPIRIT 1 and 2 trials previously demonstrated that relugolix CT significantly reduced these symptoms over 24 weeks. Building on this, the LTE study provided up to an additional 80 weeks of treatment which evaluated the long-term efficacy and safety of this regimen.

The participants included premenopausal women aged 18 to 50 who had completed the initial 24-week trials. The primary endpoints of the study were the proportion of responders for dysmenorrhea and NMPP at Week 52 and Week 104. A responder was defined as someone who achieved a clinically meaningful reduction in pain scores without an increase in analgesic use. The secondary endpoints included changes in the Endometriosis Health Profile-30 (EHP-30) pain domain scores, overall pain reduction, and opioid/analgesic use.

Out of the 1261 women originally randomized, 802 enrolled in the LTE study with 681 completing 52 weeks and 501 completing 104 weeks of treatment. The participants who continued relugolix CT from the pivotal study baseline showed sustained improvements, where 84.8% responded for dysmenorrhea and 75.8% for NMPP at Week 104. Dyspareunia decreased and functional improvements were observed, with 91% of patients opioid-free and 75% analgesic-free by the end of this study.

The safety profile of relugolix CT remained consistent over the 104 weeks with no new adverse events reported after the initial 24-week period. Also, following an initial minor decrease of less than 1% in BMD at Week 24, BMD levels plateaued and remained stable through the remainder of the treatment.

A significant portion of the study population (37.4%) terminated participation early which could impact the generalizability of the findings. There is also a need for comparative data with other hormonal therapy. Despite these limitations, the study offers valuable insights. Overall, relugolix CT presents a crucial long-term treatment option that potentially reduces opioid dependency and improves the quality of life for women with endometriosis. 

Reference:

Becker, C. M., Johnson, N. P., As-Sanie, S., Arjona Ferreira, J. C., Abrao, M. S., Wilk, K., Imm, S. J., Mathur, V., Perry, J. S., Wagman, R. B., & Giudice, L. C. (2024). Two-year efficacy and safety of relugolix combination therapy in women with endometriosis-associated pain: SPIRIT open-label extension study. In Human Reproduction (Vol. 39, Issue 3, pp. 526–537). Oxford University Press (OUP). https://doi.org/10.1093/humrep/dead263