The First Triple Agonist for Antiobesity: Retatrutide

The prevalence of individuals with overweight and obesity has increased by 18% since 1990 and it is projected that by 2030, nearly 50% of US adults will have obesity. Lifestyle modifications, such as diet and exercise, typically lead to approximately 3–5% weight loss, whereas 5–15% weight loss is necessary to significantly impact obesity-associated comorbidities and improve overall health outcomes. In addition to lifestyle modifications, pharmacotherapy has been utilized as an adjunctive treatment to increase weight loss and improve health outcomes. The Food and Drug Administration has currently approved 6 drugs to treat overweight and obesity, with the recently approved drugs surging in popularity after demonstrating superior weight loss outcomes. Additionally, a number of agents are in the pipeline, offering promise of unprecedented degrees of weight loss. One such drug is retatrutide, which is a triple agonist targeting the glucagon-like peptide-1 receptor (GLP-1R), glucose-dependent insulinotropic polypeptide receptor, and glucagon receptor. Phase 1 and 2 clinical trials have demonstrated the safety, tolerability, and pharmacokinetics of retatrutide in patients with obesity and/or type 2 diabetes. The pharmacokinetics of retatrutide were dose proportional and its mean half-life of approximately 6 days supported a once-weekly dosing. The safety profile was similar to GLP-1R agonists and glucose-dependent insulinotropic polypeptide receptor/GLP-1R co-agonists, with gastrointestinal disorders being the most common adverse effects reported. Each trial demonstrated greater weight loss with retatrutide treatment in comparison to placebo, with greatest efficacy at higher doses. Overall, these clinical trials have demonstrated the superior efficacy of retatrutide as a weight loss medication in patients with overweight and obesity.