Abstract Context In phase 2 trials, retatrutide reduced body weight, hemoglobin A1c, and improved the lipid profiles of participants living with obesity, with and without T2D. Objective Assess plasma metabolome and lipidome changes associated with retatrutide treatment. Design Metabolomics and lipidomics were performed in fasting samples from two randomized, placebo-controlled phase 2 trials. Participants living with obesity with and without T2D were treated for 36 and 48 weeks, respectively. Setting Post-hoc exploratory analysis. Participants 282 and 213 participants in the obesity and T2D trials, respectively. Intervention(s) Obesity trial; retatrutide (1, 4, 8, 12 mg) or placebo. T2D trial: retatrutide (0.5, 4, 8, 12 mg) or placebo or dulaglutide (1.5 mg). Main Outcome Measure(s) Changes in metabolite and lipid levels with retatrutide treatment against baseline levels and placebo using multiplicity correction. Results At both primary and study endpoints for both populations, higher doses of retatrutide were associated with changes in a cluster of metabolites comprising 3-hydroxybutyrate, acetylcarnitine, free carnitine and fatty acid-derived long-chain acylcarnitines. Mediation analyses suggested that changes in these biomarkers mediated 23.2% of the weight-reduction response in participants without T2D and that this mediation was blunted to 12.7% in participants with T2D. Retatrutide treatment was also associated with changes in metabolites associated with insulin resistance, including branched-chain amino acids and their catabolic products, 2-aminoadipic acid, 2-hydroxybutyrate, urate, and triglycerides enriched in short-chain and saturated acyl side chains. These changes were found in both study populations and sustained across study endpoints. Conclusions Retatrutide was associated with changes in two metabolic clusters related to fatty acid oxidation and insulin resistance in a direction associated with improved metabolic health and reduced cardiovascular risk.
Pearson et al. (Wed,) studied this question.