RHYTHM PHARMACEUTICALS, INC. (RYTM)

Rhythm Pharmaceuticals is a global, commercial-stage biopharmaceutical company focused on rare neuroendocrine diseases. It develops melanocortin-4 receptor (MC4R) agonists as precision medicines for hyperphagia (pathological, insatiable hunger) and severe obesity caused by impaired signaling in the MC4R pathway, a brain pathway that regulates hunger, caloric intake and energy expenditure. Targeted conditions include Bardet-Biedl syndrome (BBS), acquired and congenital hypothalamic obesity, Prader-Willi syndrome (PWS), and several genetically defined obesities.

The lead product is IMCIVREE (setmelanotide), for which the company holds worldwide rights. It was first approved in the United States in 2020 and is marketed in the U.S., European Union, United Kingdom, Canada and other regions for obesity due to BBS and to POMC, PCSK1 or LEPR deficiency. It has gained approvals, reimbursed access or named patient sales in more than 25 countries beyond the U.S. A U.S. FDA decision on setmelanotide for acquired hypothalamic obesity is pending (PDUFA date March 20, 2026), with reviews also ongoing in Europe and a planned submission in Japan. The pipeline includes bivamelagon, an oral MC4R agonist heading toward a Phase 3 trial in hypothalamic obesity, and RM-718, a weekly subcutaneous MC4R agonist in a Phase 1/2 trial. Both are designed to spare MC1R and avoid hyperpigmentation. Setmelanotide is also being studied in congenital hypothalamic obesity, in PWS (Phase 2), and in the Phase 3 EMANATE trial across four genetically defined MC4R pathway diseases. The company also has preclinical work on congenital hyperinsulinism.

Its customers are patients with rare MC4R pathway diseases, along with the physicians and healthcare providers who treat severe obesity. The company estimates about 4,000 to 5,000 BBS patients in the U.S., about 10,000 U.S. patients with acquired hypothalamic obesity, and about 20,000 U.S. patients with PWS. It estimates similar prevalence in Europe and 5,000 to 8,000 acquired hypothalamic obesity patients in Japan. Existing obesity drugs and bariatric surgery do not address the underlying MC4R impairment. Rhythm runs awareness and patient-finding efforts, including genetic testing programs and a DNA database of roughly 120,000 sequencing samples, and has field teams in the U.S. and Europe and a team preparing for Japan.

As of February 1, 2026, the company had 414 employees, 126 of them in 11 countries outside North America. The text does not describe suppliers, manufacturing, competitors or headquarters location.