Efficacy of novel melanocortin and GUT-peptide dual agonists for childhood obesity treatment

The federal Project Grant award R21HD115119, totaling $531,174, was provided by the National Institute of Child Health and Human Development (NICHD) under the Child Health and Human Development Extramural Research program (CFDA 93.865). The grant aims to develop and test novel dual agonist therapies targeting the melanocortin and gut-peptide receptors for the treatment of childhood obesity.

The research plan includes two specific aims: 1) fully characterizing and optimizing a GLP-1R/MC4R dual agonist peptide, KCEM1, to evaluate its efficacy in preventing and reversing diet-induced obesity and improving glycemic control in animal models, and 2) creating and evaluating novel Y2R/MC4R dual agonists as an alternative pathway for weight loss. This work involves collaboration with sub-awardees at the University of Washington, who will provide expertise in indirect calorimetry measurements, and Syracuse University, who will support medicinal chemistry and receptor binding studies. The project period runs from September 2024 through August 2026.

Abstract

The high prevalence of pediatric obesity requires new anti-obesity agents with increased efficacy, safety, and tolerance. Recent treatments based on endogenous GUT peptides such as glucagon-like peptide-1 receptor agonists (GLP-1RAS) are effective at inducing weight loss through a suppression of food intake, but they are often associated with nausea/malaise and gastrointestinal ailments, leading to poor compliance with, or discontinuation of, treatment, particularly in children and adolescents. The melanocortin (MC) pathway, in particular central MC4-receptor (MC4R) signaling, has been implicated in the regulation of energy homeostasis. Previous evidence, including our own, has shown that treatment with MCR agonists is effective at inducing weight loss in obese patients caused by deficient hypothalamic MC signaling, including patients with genetic obesity and forms of hypothalamic injury-related obesity, in part, by increasing energy expenditure. While treatment with the MC4R agonist setmelanotide (setmel) is effective, as a monotherapy IT is limited, and there may also be unwanted off-target effects such as non-selective MC1R-mediated melanocyte stimulation and hyperpigmentation. Our group has therefore focused on the development of a new generation of therapeutics that target multiple receptors of complementary neurocircuits regulating energy balance to induce greater weight loss, with minimal side effects. In support of this, our recently published findings show that our first TRI-agonist GEP44, which targets the GLP-1R and the neuropeptide receptors Y1R and anorexigenic Y2-r, reduces feeding and body weight in diet-induced obese (DIO) rodents and shrews more potently than GLP-1RAS exendin-4 and liraglutide, but without nausea and emesis. Based on these findings, we recently developed a novel GLP- 1R/MC4R dual agonist (KCEM1) and our preliminary data show that treatment of DIO rats with KCEM1 reduced food intake and body weight, and improved glycemic control compared to controls, and these effects were stronger VS. Equimolar injections of the GLP-1RA liraglutide, and semaglutide, respectively. The goal of this research is to: 1) fully characterize and develop our GLP-1R/MC4R monomeric peptide dual agonists with improved efficacy by optimizing specific MC4R binding (over MC1/2/3/5RS), and 2), create two novel neuropeptide y receptor Y2R/MC4R agonists, which act independently of the GLP-1R pathway entirely thus avoiding associated side-effects. Specific aim 1 will test the hypothesis that KCEM1 both prevents and reverses DIO and improves glucoregulation relative to vehicle and FDA-approved single agonists. Comprehensive measures of energy homeostasis will be supported by the nutrition obesity research center energy balance core at the university of washington. Specific aim 2 (exploratory) will develop novel GLP-1R/MC4R and Y2R/MC4R dual agonists including long-acting lipidated multiagonists, and elucidate their penetration into the brain, receptor binding, and tissue-specific mechanisms in brain areas of energy homeostasis and peripheral tissues. Together, this work is expected to identify novel, safe, and effective treatments for pediatric obesity.