Setmelanotide, marketed by Rhythm Pharmaceuticals as IMCIVREE, is a cyclic peptide melanocortin-4 receptor (MC4R) agonist that restores signaling in patients whose MC4R-pathway hunger-and-energy-balance circuit is broken by genetic defects upstream of MC4R or by structural damage to the hypothalamus. The drug is the first approved targeted therapy for several rare genetic obesity syndromes and the first medication to treat acquired hypothalamic obesity following brain tumor surgery or trauma.
The FDA approved IMCIVREE in 2020 for POMC, PCSK1, and LEPR deficiency obesity, expanded the label to Bardet-Biedl Syndrome (BBS) in 2022, and added acquired hypothalamic obesity in March 2026 after the Phase 3 TRANSCEND trial showed an 18.4% placebo-adjusted BMI reduction at 52 weeks. Q1 2026 IMCIVREE net product revenue hit $60.1M (up 59% YoY). At ENDO 2026 in Chicago, Rhythm presented seven setmelanotide abstracts across three indications: a 2.5-year long-term extension in acquired hypothalamic obesity (-18.9% mean BMI reduction), interim Phase 2 data in Prader-Willi Syndrome (3.0-3.1% BMI reduction with lean-mass preservation), and real-world Bardet-Biedl Syndrome outcomes from the 6-month RESTORE study. The Phase 3 EMANATE program in broader MC4R-pathway diseases missed its primary endpoint in May 2026, narrowing the indication-expansion runway.
Stories here cover setmelanotide trial readouts, commercial uptake, and the MC4R competitive set. See [[rhythm-pharmaceuticals]], [[mc4r]], and [[hypothalamic-obesity]] for adjacent threads.
Rhythm Pharmaceuticals (Nasdaq: RYTM) presented seven setmelanotide abstracts at ENDO 2026 covering three rare-disease patient populations. Christian Roth (Seattle Children's) reported 2.5-year Phase 2 + long-term extension data in acquired hypothalamic obesity showing -18.9% mean BMI reduction across all 11 participants. The PWS interim Phase 2 (June 13) reported across 17 patients (10 adult, 7 pediatric) showed 3.11% mean BMI reduction in adults and 3.00% in pediatric patients, with 8 of 10 baseline-hyperphagic patients hitting a 7-point HQ-CT reduction, and 4.19% fat-mass loss with 0.74% lean-mass gain across 16 DEXA evaluations. Two BBS late-breaking posters from Caroline Huber covered real-world hyperphagia and healthcare-utilization outcomes from the 6-month RESTORE study. All three indications reinforce the MC4R-agonist rationale for Phase 3.
Rhythm Pharmaceuticals reported Q1 2026 results May 5: setmelanotide (IMCIVREE) net product revenue of $60.1M, up from $37.7M a year earlier ($36.9M US, $23.2M ex-US), driven by 150+ new US start forms in acquired hypothalamic obesity following the FDA approval and the EU Marketing Authorization for the same indication; Japan's PMDA accepted the NDA for review. The MC4R-agonist peptide is the only commercial therapy for hypothalamic obesity. Offsetting the topline beat: the Phase 3 EMANATE trial in genetically caused MC4R-pathway diseases failed its primary endpoint in all four independent substudies, narrowing the indication-expansion runway. Net loss was $56.7M; cash $340.6M for 24+ months runway.
FDA approved setmelanotide (IMCIVREE), an MC4R agonist peptide, for reducing body weight in adults and children aged 4+. Phase 3 TRANSCEND trial showed 18.4% placebo-adjusted BMI reduction at 52 weeks.