Setmelanotide Research & Studies

Setmelanotide, a melanocortin-4 receptor (MC4R) agonist, has been shown to reduce hunger and weight in patients aged 6 years and older with proopiomelanocortin (POMC) deficiency (including biallelic variants in proprotein convertase subtilisin/kexin type 1 [PCSK1]), leptin receptor (LEPR) deficiency, or Bardet-Biedl syndrome (BBS). No approved therapies for patients younger than 6 years old currently exist. The phase 3, open-label VENTURE trial aimed to evaluate the efficacy and safety of setmelanotide in patients aged 2-5 years with POMC or LEPR deficiency or BBS.

To compare the risk of primary open-angle glaucoma (POAG) and ocular hypertension in patients with obesity taking glucagon-like peptide 1 receptor agonists (GLP-1RAs) versus alternative weight loss medications.

Following the diagnosis of craniopharyngioma, patients frequently experience rapid and excessive weight gain resulting in morbid hypothalamic obesity. This condition is commonly attributed to damage to hypothalamic structures caused either by the tumor itself or its treatment. Hypothalamic obesity should be understood and managed within the broader clinical framework of hypothalamic syndrome, a complex condition characterized by multiple neuroendocrine deficiencies, disruption of circadian rhythms, dysregulation of hunger, satiety and thirst, altered thermoregulation, as well as cognitive, sleep-related, and psychosocial impairments. The long-term outlook for affected individuals is often poor, primarily due to an elevated risk of developing metabolic syndrome, cardiovascular disease, significant reductions in health-related quality of life, and increased risk of early mortality. Management of hypothalamic syndrome remains highly challenging. Recently, a risk-adapted, personalized treatment algorithm has been proposed to guide clinical care. Therapeutic interventions such as dextroamphetamine and other centrally acting stimulants, along with glucagon-like peptide-1 receptor (GLP-1R) agonists, and setmelanotide have shown potential in promoting weight reduction. Bariatric surgery has also demonstrated efficacy; however, the use of irreversible surgical techniques in pediatric populations remains ethically and legally contentious. This report summarizes perspectives of future research and clinical progress in diagnostics, treatment, and follow-up of patients with craniopharyngioma.

The development of novel sophisticated medications that induce weight loss has revolutionized the management of people living with obesity (PwO). However, when body weight is reduced, muscle and bone are lost along with fat. In the present review, we quote and discuss existing evidence on the effects of the major anti-obesity medications on bone metabolism. Glucagon-like peptide-1 receptor (GLP-1R) agonists have shown a positive impact in preclinical studies but a neutral or negative, albeit not clinically significant, effect on bone turnover markers and bone mineral density in clinical studies. Nevertheless, fracture risk does not seem to increase with GLP-1R agonists use, at least in clinically relevant doses. Limited, mostly preclinical, data suggest that other incretin analogues, including dual GLP-1R and glucose-dependent insulinotropic polypeptide (GIP) receptor (GIPR) agonists, dual GLP-1R and glucagon receptor (GCGR) agonists, and triple GLP-1R, GIPR and GCGR agonists, may have a positive effect on bone. Preclinical data with amylin analogues imply the same. Activin type II receptor (ActRII) antagonists may combine anti-obesity effects with simultaneous muscle and bone mass preservation and could be used either as monotherapy or in combination with incretin analogues. The bone effects of opioid receptor antagonists and setmelanotide are largely unknown, while the impact of the combination of phentermine with topiramate is assumed to be negative. Finally, very limited clinical evidence suggests that orlistat may have a neutral effect on bone metabolism.

In this narrative review we describe the recent updates regarding anti-obesity medications as of February 2025. We describe the physiologic mechanisms underpinning the development of hunger, satiation, and maintenance of satiety to address targets for anti-obesity medications. The efficacy, mechanism, and additional beneficial effects of anti-obesity medications are then further detailed. For this review, we focus on FDA-approved medications for obesity and on select medications currently under development and undergoing Phase 2 and 3 trials. We start by focusing on the non-incretin anti-obesity medications orlistat, phentermine, phentermine-topiramate, and naltrexone-bupropion. We also highlight setmelanotide for heritable obesity. The mechanism of action and comparative efficacy of the GLP-1 receptor agonists liraglutide and semaglutide are reviewed. Tirzepatide, the GLP-1 and GIP-receptor dual agonist is described, and weight loss is compared to alternative anti-obesity medications. Additional incretin targets in the pipeline include dual co-agonists to glucagon and GLP-1 receptors, triple agonists targeting glucagon, GLP-1 and GIP, novel GLP-1 agonists, oral formulations of GLP-1 agonists, and amylin agonists. Finally, we provide best practices for adjuncts to pharmacologic treatments of obesity, monitoring efficacy of obesity treatments, and adjusting medication regimens for providers.

Hypothalamic obesity (HO) is a rare and complex disorder that confers substantial morbidity and excess mortality. HO is a unique subtype of obesity characterized by impairment in the key brain pathways that regulate energy intake and expenditure, autonomic nervous system function, and peripheral hormonal signalling. HO often occurs in the context of hypothalamic syndrome, a constellation of symptoms that follow from disruption of hypothalamic functions, for example, temperature regulation, sleep-wake circadian control, and energy balance. Genetic forms of HO, including the monogenic obesity syndromes, often impact central leptin-melanocortin pathways. Acquired forms of HO occur as a result of tumours impacting the hypothalamus, such as craniopharyngioma, surgery or radiation to treat those tumours, or other forms of hypothalamic damage, such as brain injury impacting the region. Risk for severe obesity following hypothalamic injury is increased with larger extent of hypothalamic damage or lesions that contain the medial and posterior hypothalamic nuclei that support melanocortin signalling pathways. Structural damage in these hypothalamic nuclei often leads to hyperphagia, central insulin and leptin resistance, decreased sympathetic activity, low energy expenditure, and increased energy storage in adipose tissue, the collective effect of which is rapid weight gain. Individuals with hyperphagia are perpetually hungry. They do not experience fullness at the end of a meal, nor do they feel satiated after meals, leading them to consume larger and more frequent meals. To date, most efforts to treat HO have been disappointing and met with limited, if any, long-term success. However, new treatments based on the distinct pathophysiology of disturbed energy homeostasis in acquired HO may hold promise for the future.

Hypothalamic obesity resulting from hypothalamic damage might affect melanocortin signalling. We investigated the melanocortin-4 receptor agonist setmelanotide for treatment of hypothalamic obesity.

Bardet-Biedl syndrome (BBS) is a rare genetic disease associated with hyperphagia, a pathologic insatiable hunger, due to impaired signaling in the melanocortin-4 receptor (MC4R) pathway. The impact of hyperphagia on the lives of patients with BBS and their families has not been fully characterized.

Prader-Willi syndrome (PWS) is a complex, genetic, neurodevelopmental disorder. PWS has three molecular genetic classes. The most common defect is due to a paternal 15q11-q13 deletion observed in about 60% of individuals. This is followed by maternal disomy 15 (both 15 s from the mother), found in approximately 35% of cases. the remaining individuals have a defect of the imprinting center that controls the activity of imprinted genes on chromosome 15. Mild cognitive impairment and behavior problems in PWS include self-injury, anxiety, compulsions, and outbursts in childhood, impacted by genetic subtypes. Food seeking and hyperphagia can lead to morbid obesity and contribute to diabetes and cardiovascular or orthopedic problems. The control of hyperphagia and improving food-related behaviors are the most important unmet needs in PWS and could be addressed with the development of a new therapeutic agent, as currently no approved therapeutics exist for PWS treatment. The status of clinical trials with existing results for the management of obesity and hyperphagia in PWS will be discussed in this review, including treatments such as beloranib, setmelanotide, a diazoxide choline controlled-release tablet (DCCR), an unacylated ghrelin analogue, oxytocin and related compounds, glucagon-like peptide 1 receptor agonists, surgical intervention, and transcranial direct-current stimulation.

Similar to the general population, lifestyle interventions focused on nutrition and physical activity form the foundation for treating obesity caused by rare genetic disorders. Additional therapies, including metreleptin and setmelanotide, that target defects within the leptin signaling pathway can effectively synergize with lifestyle efforts to treat monogenic disorders of leptin, leptin receptor, proopiomelanocortin (POMC), and proprotein convertase subtilisin/kexin type 1 (PCSK1) and syndromic conditions, such as the ciliopathies Bardet-Biedl and Alström syndromes, whose pathophysiological mechanisms also converge on the leptin pathway. Investigational treatments for Prader-Willi syndrome target specific defects caused by reduced expression of paternally derived genes within the chromosome 15q region.

In patients with pro-opiomelanocortin (POMC) or leptin receptor (LEPR) deficiency, managing obesity and hyperphagia can be burdensome for patients and caretakers. The impacts on health-related quality of life are under-recognized and are not well characterized.

Over the past 20 years, insights from human and mouse genetics have illuminated the central role of the brain leptin-melanocortin pathway in controlling mammalian food intake, with genetic disruption resulting in extreme obesity, and more subtle polymorphic variations influencing the population distribution of body weight. At the end of 2020, the U.S. Food and Drug Administration (FDA) approved setmelanotide, a melanocortin 4 receptor agonist, for use in individuals with severe obesity due to either pro-opiomelanocortin (POMC), proprotein convertase subtilisin/kexin type 1 (PCSK1), or leptin receptor (LEPR) deficiency.

Setmelanotide (IMCIVREE™, Rhythm Pharmaceuticals) is a melanocortin-4 (MC4) receptor agonist developed for the treatment of obesity arising from proopiomelanocortin (POMC), proprotein convertase subtilisin/kexin type 1 (PCSK1), or leptin receptor (LEPR) deficiency. The drug has received its first approval in the USA for chronic weight management in patients 6 years and older with obesity caused by POMC, PCSK1 and LEPR deficiency and has been granted PRIority MEdicines (PRIME) designation by the European Medicines Agency for the treatment of obesity and the control of hunger associated with deficiency disorders of the MC4 receptor pathway. Setmelanotide is also being developed in other rare genetic disorders associated with obesity including Bardet-Biedl Syndrome, Alström Syndrome, POMC and other MC4R pathway heterozygous deficiency obesities, and POMC epigenetic disorders. This article summarizes the milestones in the development of setmelanotide leading to this first approval for obesity caused by POMC, PCSK1 and LEPR deficiency.

The melanocortin 4 receptor (MC4R), a component of the leptin-melanocortin pathway, plays a part in bodyweight regulation. Severe early-onset obesity can be caused by biallelic variants in genes that affect the MC4R pathway. We report the results from trials of the MC4R agonist setmelanotide in individuals with severe obesity due to either pro-opiomelanocortin (POMC) deficiency obesity or leptin receptor (LEPR) deficiency obesity.

Pro-opiomelanocortin (POMC)-derived peptides act on neurons expressing the Melanocortin 4 receptor (MC4R) to reduce body weight. Setmelanotide is a highly potent MC4R agonist that leads to weight loss in diet-induced obese animals and in obese individuals with complete POMC deficiency. While POMC deficiency is very rare, 1-5% of severely obese individuals harbor heterozygous mutations in MC4R. We sought to assess the efficacy of Setmelanotide in human MC4R deficiency.