Rhythm Pharmaceuticals Announces that Setmelanotide Has Been Granted Orphan Drug Designation in Japan for Hypothalamic Obesity

BOSTON, Mass. — Rhythm Pharmaceuticals, Inc. (Nasdaq: RYTM), a global commercial-stage biopharmaceutical company focused on transforming the lives of patients living with rare neuroendocrine diseases, today announced it has received orphan drug designation from Japan’s Ministry of Health, Labour and Welfare (MHLW) for setmelanotide as a treatment for acquired hypothalamic obesity.

Setmelanotide is a melanocortin-4 receptor (MC4R) agonist designed to treat hyperphagia and obesity. Rhythm is evaluating setmelanotide in a global Phase 3 trial in patients with acquired hypothalamic obesity, with topline data on track to be disclosed in the second quarter of 2025.

“Orphan drug designation points to the need for therapeutic options for people living with acquired hypothalamic obesity,” said Yann Mazabraud, Executive Vice President, Head of International at Rhythm Pharmaceuticals. “With this designation now in place in Japan, as well as in Europe, we believe we are well positioned to execute on our global strategy to bring patients with hypothalamic obesity the first-ever treatment targeting the underlying biology of this disease, pending success of our Phase 3 trial and subsequent regulatory filings.”

Acquired hypothalamic obesity is a disease characterized by accelerated and sustained change in weight trajectory caused by an injury to the hypothalamus, often accompanied by hyperphagia (pathological, insatiable hunger and impaired satiety accompanied by abnormal food-seeking behaviors) and/or decreased energy expenditure. Acquired hypothalamic obesity most frequently follows hypothalamic injury from the growth or surgical removal of craniopharyngioma, astrocytoma, or other rare brain tumors. Additional causes of injury may include traumatic brain injury, stroke, or inflammation due to infection.

“There is a significant unmet medical need in Japan for a safe and effective precision medicine for patients living with acquired hypothalamic obesity, said Prof. Arima, MD, PhD, Professor of the Department of Endocrinology and Diabetes, Nagoya University Graduate School of Medicine. “Setmelanotide could provide new hope to these patients and their families.”

In Japan, drugs can be designated as orphan drugs if they treat diseases affecting fewer than 50,000 patients in Japan and there is a high medical need. Rhythm estimates there are 5,000 to 8,000 people living with acquired hypothalamic obesity in Japan, 5,000 to 10,000 people living with acquired hypothalamic obesity in the U.S., and 3,500 to 10,000 people living with acquired hypothalamic obesity in the E.U.

 

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) to reduce excess body weight and maintain weight reduction long term in adult and pediatric patients 2 years of age and older with syndromic or monogenic obesity due to Bardet-Biedl syndrome (BBS) or genetically confirmed pro-opiomelanocortin (POMC), including proprotein convertase subtilisin/kexin type 1 (PCSK1), deficiency or leptin receptor (LEPR) deficiency. 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 2 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 to reduce excess body weight and maintain weight reduction long term in adult and pediatric patients aged 2 years and older with syndromic or monogenic obesity due to Bardet-Biedl syndrome (BBS) or Pro-opiomelanocortin (POMC), proprotein convertase subtilisin/kexin type 1 (PCSK1), or leptin receptor (LEPR) deficiency as determined by an FDA-approved test demonstrating variants in POMCPCSK1, or LEPR genes that are interpreted as pathogenic, likely pathogenic, or of uncertain significance (VUS). In the European Union and the United Kingdom, 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 2 years of age and above. In the European Union and the United Kingdom, setmelanotide should be prescribed and supervised by a physician with expertise in obesity with underlying genetic etiology.

Limitations of Use
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 POMCPCSK1, or LEPR variants classified as benign or likely benign
  • Other types of obesity not related to BBS or POMC, PCSK1, or LEPR deficiency, 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.

WARNINGS AND PRECAUTIONS
Disturbance in Sexual Arousal: Spontaneous penile erections in males and sexual adverse reactions in females have occurred. Inform patients that these events may occur and instruct patients who have an erection lasting longer than 4 hours to seek emergency medical attention.

Depression and Suicidal Ideation: Depression, suicidal ideation and depressed mood have occurred. Monitor patients for new onset or worsening depression or suicidal thoughts or behaviors. Consider discontinuing IMCIVREE if patients experience suicidal thoughts or behaviors, or clinically significant or persistent depression symptoms occur.

Hypersensitivity Reactions: Serious hypersensitivity reactions (e.g., anaphylaxis) have been reported. If suspected, advise patients to promptly seek medical attention and discontinue IMCIVREE.

Skin Hyperpigmentation, Darkening of Pre-existing Nevi, and Development of New Melanocytic Nevi: Generalized or focal increases in skin pigmentation, darkening of pre-existing nevi, development of new melanocytic nevi and increase in size of existing melanocytic nevi have occurred. Perform a full body skin examination prior to initiation and periodically during treatment to monitor pre-existing and new pigmented lesions.

Risk of Serious Adverse Reactions Due to Benzyl Alcohol Preservative in Neonates and Low Birth Weight Infants: IMCIVREE is not approved for use in neonates or infants. Serious and fatal adverse reactions including “gasping syndrome” can occur in neonates and low birth weight infants treated with benzyl alcohol preserved drugs.

ADVERSE REACTIONS
Most common adverse reactions (incidence ≥20%) included skin hyperpigmentation, injection site reactions, nausea, headache, diarrhea, abdominal pain, vomiting, depression, and spontaneous penile erection.

USE IN SPECIFIC POPULATIONS
Treatment with IMCIVREE is not recommended when breastfeeding. Discontinue IMCIVREE when pregnancy is recognized unless the benefits of therapy outweigh the potential risks to the fetus.

To report SUSPECTED ADVERSE REACTIONS, contact Rhythm Pharmaceuticals at +1 (833) 789-6337 or FDA at 1-800-FDA-1088 or www.fda.gov/medwatch. See section 4.8 of the Summary of Product Characteristics for information on reporting suspected adverse reactions in Europe.

Please see the full Prescribing Information for additional Important Safety Information.

 

Contact
David Connolly
Head of Investor Relations and Corporate Communications
Rhythm Pharmaceuticals, Inc.
857-264-4280
dconnolly@rhythmtx.com

Contact
Sheryl Seapy
Real Chemistry
(949) 903-4750
sseapy@realchemistry.com