Rhythm Pharmaceuticals, Inc. announced that the first patients have been dosed in the Company?s Phase 1 clinical trial of RM-718, an investigational, weekly melanocortin-4 receptor (MC4R)-specific agonist designed to be MC1R-sparing and to potentially avoid hyperpigmentation. This Phase 1 trial is a three-part study to evaluate safety, tolerability and pharmacokinetics (PK). The study consists of Part A: single ascending doses (SAD) of RM-718 in healthy participants 18 to 55 years old with obesity; Part B: multiple ascending doses (MAD) of RM-718 in healthy participants 18 to 55 years old with obesity; and Part C: MAD of RM-718 in patients 12 to 65 years old with hypothalamic obesity.

Cohorts in Parts A and B are double-blind, placebo-controlled, and randomized 2:1. Study participants will receive one weekly dose of either RM-718 or placebo in Part A, four weekly doses of either RM-718 or placebo in Part B, and four weekly doses of open-label RM-718 in Part C. RM-718 or placebo doses are administered weekly via subcutaneous injection. The anticipated enrollment for this study is 96 participants. In the United States, setmelanotide is indicated for chronic weight management in adult and pediatric patients 6 years of age and older with monogenic or syndromic obesity due to POMC, PCSK1 or LEPR deficiency as determined by an FDA-approved test demonstrating variants in POMC, PCSK1 or LEPR genes that are interpreted as pathogenic, likely pathogenic, or of uncertain significance (VUS) or BBS.

In the European Union, setmelanotide is indicated for the treatment of obesity and the control of hunger associated with genetically confirmed BBS or loss-of-function biallelic POMC, including PCSK1, deficiency or biallelic LEPR deficiency in adults and children 6 years of age and above. In Europe, setmelanotide should be prescribed and supervised by a physician with expertise in obesity with underlying genetic etiology. Setmelanotide is not indicated for the treatment of patients with the following conditions as setmelanotide would not be expected to be effective: Obesity due to suspected POMC, PCSK1 or LEPR deficiency with POMC, PCSK1 or LEPR variants classified as benign or likely benign, Other types of obesity not related to POMC, PCSK1 or LEPR deficiency, or BBS, including obesity associated with other genetic syndromes and general (polygenic) obesity.

Contraindication: Prior serious hypersensitivity to setmelanotide or any of the excipients in IMCIVREE. Serious hypersensitivity reactions (e.g., anaphylaxis) have been reported.