FRI082 Impact Of Setmelanotide On Metabolic Parameters And Vital Signs In Patients With Hypothalamic Obesity

Disclosure: M.J. Abuzzahab: Advisory Board Member; Self; Pfizer, Inc., Endo Pharmaceuticals, Rhythm Pharmaceuticals, Inc., Consynance. Consulting Fee; Self; Pfizer, Inc., Endo Pharmaceuticals, Consynance, Rhythm Pharmaceuticals, Inc. A. Shoemaker: Advisory Board Member; Self; Rhythm Pharmaceuticals, Saniona. M. Gottschalk: Advisory Board Member; Self; Rhythm Pharmaceuticals, Inc. Consulting Fee; Self; Rhythm Pharmaceuticals, Inc. J. Miller: Other; Self; Study funding from Rhythm Pharmaceuticals, Inc. G. Yuan: Employee; Self; Rhythm Pharmaceuticals, Inc. Stock Owner; Self; Rhythm Pharmaceuticals, Inc. S. Malhotra: Employee; Self; Rhythm Pharmaceuticals, Inc. Stock Owner; Self; Rhythm Pharmaceuticals, Inc. C. Scimia: Employee; Self; Rhythm Pharmaceuticals, Inc. Stock Owner; Self; Rhythm Pharmaceuticals, Inc. C.L. Roth: Other; Self; Study funding from Rhythm Pharmaceuticals, Inc. Background: Hypothalamic obesity (HO) is a severe form of obesity that results from insult to the hypothalamus, primarily from tumors, tumor resections, and radiotherapy treatment, which can impair melanocortin-4 receptor (MC4R) pathway signaling. Treatment with setmelanotide, an MC4R agonist, resulted in weight loss and hunger reduction in a Phase 2 trial of patients with HO. This analysis evaluated the impact of 16 weeks of setmelanotide on metabolic parameters and vital signs in patients with HO. Methods: A Phase 2 open-label trial of setmelanotide enrolled patients aged ≥6 to ≤40 years with obesity resulting from hypothalamic injury who completed tumor-related treatment ≥6 months before enrollment (NCT04725240). The primary endpoint was the proportion of patients with ≥5% reduction in baseline body mass index (BMI) after 16 weeks of setmelanotide. Exploratory endpoints of change from baseline in waist circumference and metabolic parameters, including fasting glucose and glycated hemoglobin, were evaluated. Vital signs, including heart rate and blood pressure, were also assessed. Descriptive statistics including changes at Week 16 from baseline are reported. Results: Eighteen patients were included in the study. At Week 16, most patients met the primary endpoint (88.9% [n/N=16/18]; P<0.0001), and 13 of 18 patients who completed treatment had ≥10% BMI reduction (mean [standard deviation (SD)] percent change, −14.5% [9.5%]). Across all patients, body weight was reduced by a mean (SD) of 12.6% (9.1%), and change in BMI Z score in patients aged ≥6 to <18 years was −1.3 (1.0). Overall, waist circumference was reduced by a mean (SD) of 12.0 (5.8) cm, which was a 10.4% (5.2%) reduction. Weight loss was predominately due to reduction in total fat mass rather than loss of lean mass. Most mean metabolic and vital sign values were within normal ranges at baseline, and given the short duration of the study, no changes in metabolic parameters were noted. Vital signs continued to remain normal during the 16-week study duration. Treatment-related adverse events occurred in all patients. The most frequent adverse events included nausea (61.1%; n=11), vomiting (33.3%; n=6), skin hyperpigmentation (33.3%; n=6), and diarrhea (22.2%; n=4). Conclusions: In a heterogeneous population of patients with HO secondary to treatment of hypothalamic tumors, setmelanotide led to weight loss and reduction in BMI and a favorable change in body composition. Efficacy and safety of setmelanotide will continue to be evaluated in a larger Phase 3 clinical trial. Presentation: Friday, June 16, 2023