Once-Monthly Maridebart Cafraglutide for the Treatment of Obesity — A Phase 2 Trial

BACKGROUND: Maridebart cafraglutide (known as MariTide) is a long-acting peptide-antibody conjugate that combines glucagon-like peptide-1 receptor agonism and glucose-dependent insulinotropic polypeptide receptor antagonism and that is intended for the treatment of obesity. METHODS: We conducted a phase 2, double-blind, randomized, placebo-controlled, dose-ranging trial that included 11 groups as two cohorts. Participants with obesity (obesity cohort) were randomly assigned in a 3:3:3:2:2:2:3 ratio to receive maridebart cafraglutide subcutaneously at a dose of 140, 280, or 420 mg every 4 weeks without dose escalation; 420 mg every 8 weeks without dose escalation; 420 mg every 4 weeks with 4-week dose escalation; 420 mg every 4 weeks with 12-week dose escalation; or placebo. Participants with obesity with type 2 diabetes (obesity-diabetes cohort) were randomly assigned in a 1:1:1:1 ratio to receive maridebart cafraglutide at a dose of 140, 280, or 420 mg every 4 weeks (all without dose escalation) or placebo. The primary end point was the percent change in body weight from baseline to week 52. RESULTS: We enrolled 592 participants. In the obesity cohort (465 participants; female sex, 63%; mean age, 47.9 years; mean body-mass index [BMI, the weight in kilograms divided by the square of the height in meters], 37.9), the mean percent change in body weight from baseline to week 52 on the basis of the treatment policy estimand (intention-to-treat approach) ranged from -12.3% (95% confidence interval [CI], -15.0 to -9.7) to -16.2% (95% CI, -18.9 to -13.5) with maridebart cafraglutide, as compared with -2.5% (95% CI, -4.2 to -0.7) with placebo. In the obesity-diabetes cohort (127 participants; female sex, 42%; mean age, 55.1 years; mean BMI, 36.5), the mean percent change in body weight from baseline to week 52 on the basis of the treatment policy estimand ranged from -8.4% (95% CI, -11.0 to -5.7) to -12.3% (95% CI, -15.3 to -9.2) with maridebart cafraglutide, as compared with -1.7% (95% CI, -2.9 to -0.6) with placebo. The mean change in the glycated hemoglobin level on the basis of the treatment policy estimand in this cohort was -1.2 to -1.6 percentage points in the maridebart cafraglutide groups and 0.1 percentage points in the placebo group. Gastrointestinal adverse events were common with maridebart cafraglutide, although less frequent with dose escalation and a lower starting dose. No unexpected safety signals emerged. CONCLUSIONS: In this phase 2 trial, once-monthly maridebart cafraglutide resulted in substantial weight reduction in participants with obesity with or without type 2 diabetes. (Funded by Amgen; ClinicalTrials.gov number, NCT05669599.).