Real Life Data for Relugolix/Estradiol/Norethisteroneacetate Treatment for Chronic Pelvic Pain in Endometriosis Patients

Background/objective: Relugolix–estradiol–norethisterone acetate combination therapy (relugolix CT) was licensed for endometriosis-associated pain on the strength of two big randomized controlled trials, in which dysmenorrhea improved in 73–74% and non-cyclical pelvic pain in 58–60% of participants, with discontinuation for adverse events in about 4%. Whether this performance is reproduced outside a trial setting, in patients who have already failed first-line progestin therapy and carry a high burden of deep infiltrating disease, has not previously been reported. Methods: Single-center retrospective cohort study at a tertiary endometriosis referral center. Of 917 endometriosis patients seen for chronic pelvic pain between January 2021 and September 2025, relugolix CT was prescribed to 100 patients of whom disease was confirmed by either imaging- or surgery. Clinician-recorded patient-reported change from baseline was assessed at 3, 6 and 12 visit windows, globally and by symptom domain. Outcomes of efficacy and safety and are recorded in a descriptive way, according to available data. Patients stopping for non-treatment related reasons are corrected for. Results: Of the total cohort, 66 patients had available outcomes for the efficacy analysis. 92% had deep infiltrating disease and 89% had failed at least one progestin-only therapy. Treatment discontinuation was 42/66 (64%) over 12 months, most often for persistent pain (17/42) or for pain with intolerable side effects (12/42). Early discontinuation was mainly driven by side effects, or later discontinuation by inadequate pain control. On the on-treatment analysis, dysmenorrhea improved in 34/48 (71%), 28/47 (60%) and 25/45 (56%) at 3, 6 and 12 months; chronic pelvic pain in 20/39 (51%), 22/45 (49%) and 22/44 (50%); and bleeding in 21/30 (70%), 21/28 (75%) and 20/27 (74%). When discontinuation due to both persistent pain and/or side effects is counted as treatment failure, the real-world figures are substantially lower and fall with time: global improvement 36/58 (62%), 21/50 (42%) and 16/43 (37%); dysmenorrhea 34/53 (64%), 19/46 (41%) and 15/42 (36%); chronic pelvic pain 20/45 (44%), 18/47 (38%) and 14/41 (34%); bleeding 21/43 (49%), 16/43 (37%) and 12/42 (29%). Adverse events were reported by 36/66 (55%) and led to discontinuation in 20/66 (30%); all five patients reporting depressive symptoms stopped treatment. Conclusions: Real-world effectiveness of relugolix CT is more limited and less durable than in the randomized trials, with roughly one third of patients still deriving benefit at twelve months. However we consider this effect clinically valuable as this is a heavily pre-treated patient population, in whom the drug was used as second-line therapy and often to avoid repeat surgery. The single-center retrospective design and the use of clinician-recorded rather than validated patient-reported outcomes limit however generalizability. Prospective multicenter confirmation is needed.