— Three-part study to evaluate safety, tolerability and pharmacokinetics now underway

— RM-718 showed potential to reduce body weight and hyperphagia, no hyperpigmentation
observed in preclinical studies —

BOSTON, MA, USA I March 25, 2024 I Rhythm Pharmaceuticals, Inc. (Nasdaq: RYTM), a commercial-stage biopharmaceutical company focused on transforming the lives of patients and their families living with rare neuroendocrine diseases, today 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.

“We are excited to begin clinical development of RM-718, our next-generation MC4R agonist,” said David Meeker, M.D., Chair, President and Chief Executive Officer of Rhythm. “Based on encouraging preclinical data, we believe RM-718 has the potential to reduce hyperphagia – a pathological hunger that leads to abnormal food-seeking behavior – and treat severe obesity, which are the two hallmark symptoms of rare MC4R pathway diseases. In addition, RM-718 was designed to provide a weekly dosing regimen and to 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.

About RM-718
RM-718 is an investigational, weekly, MC4R-specific agonist that has demonstrated the potential to reduce body weight and hunger in preclinical studies. RM-718 is designed to be highly selective and MC1Rsparing and thereby not cause hyperpigmentation.

About Rhythm Pharmaceuticals
Rhythm is a commercial-stage biopharmaceutical company committed to transforming the lives of patients and their families living with rare neuroendocrine diseases. Rhythm’s lead asset, IMCIVREE® (setmelanotide), an MC4R agonist designed to treat hyperphagia and severe obesity, is approved by the U.S. Food and Drug Administration (FDA) for chronic weight management in adult and pediatric patients 6 years of age and older with monogenic or syndromic obesity due to pro-opiomelanocortin (POMC), proprotein convertase subtilisin/kexin type 1 (PCSK1) or leptin receptor (LEPR) deficiency confirmed by genetic testing, or patients with a clinical diagnosis of Bardet-Biedl syndrome (BBS). Both the European Commission (EC) and the UK’s Medicines & Healthcare Products Regulatory Agency (MHRA) have authorized setmelanotide for the treatment of obesity and the control of hunger associated with genetically confirmed BBS or genetically confirmed loss-of-function biallelic POMC, including PCSK1, deficiency or biallelic LEPR deficiency in adults and children 6 years of age and above. Additionally, Rhythm is advancing a broad clinical development program for setmelanotide in other rare diseases, as well as investigational MC4R agonists LB54640 and RM-718, and a preclinical suite of small molecules for the treatment of congenital hyperinsulinism. Rhythm’s headquarters is in Boston, MA.

Setmelanotide Indication
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.

SOURCE: Rhythm Pharmaceuticals