Rhythm Pharmaceuticals' RM-718 Shows Promising BMI Reduction in Phase 2 Trial for Hypothalamic Obesity — Rhythm Pharmaceuticals, Inc.

Event summary

RM-718 demonstrated a -11.6% mean reduction in BMI from baseline at Week 16 in Phase 2 trial for acquired hypothalamic obesity.
BMI reductions with RM-718 were consistent with those observed with setmelanotide and bivamelagon.
Two mild instances of hyperpigmentation reported, limited to the injection site.
Eight patients remained on active treatment as of July 16, 2026.

The big picture

Rhythm Pharmaceuticals' positive Phase 2 data for RM-718 in acquired hypothalamic obesity positions the company to expand its portfolio of MC4R agonists. The results suggest potential for a next-generation treatment, though competition with existing therapies like setmelanotide and bivamelagon remains a key dynamic. The biopharmaceutical sector continues to focus on rare neuroendocrine diseases, with Rhythm aiming to leverage its expertise in this niche.

What we're watching

Clinical Efficacy: Whether RM-718 can sustain BMI reduction results in larger, longer-term studies.
Safety Profile: The impact of limited hyperpigmentation on RM-718's regulatory approval prospects.
Market Positioning: How Rhythm Pharmaceuticals positions RM-718 against existing treatments like setmelanotide and bivamelagon.