Rhythm Pharmaceuticals' RM-718 shows positive Phase 2 signal in acquired hypothalamic obesity

Rhythm Pharmaceuticals announced on 4 August 2026 preliminary data from a Phase 2 trial showing its next-generation MC4R agonist RM-718 demonstrated a positive efficacy signal in acquired hypothalamic obesity, a rare condition driven by damage to the hypothalamus.

RM-718 delivered an 11.6% mean reduction in BMI from baseline at Week 16 in the first cohort (n=7), with reductions observed across patients. Acquired hypothalamic obesity has no approved therapies; it typically results from tumours, surgery or radiation affecting the hypothalamic melanocortin pathway that governs appetite and energy balance.

RM-718 is designed to restore signalling through the melanocortin-4 receptor (MC4R), building on the company's approved MC4R agonist IMCIVREE (setmelanotide). Rhythm said the preliminary data support advancing RM-718 in the indication.

Source: Rhythm Pharmaceuticals press release, 4 August 2026.