Claimed effect · Setmelanotide

Does Setmelanotide help with weight loss in acquired hypothalamic obesity?

B
Grade B — probable, not settled1 phase 3 RCT (TRANSCEND, n=120, 52 wk) · effect size: large
Short answerProbable, not settled. Human data exist (1 phase 3 RCT (TRANSCEND, n=120, 52 wk)) and mostly agree, showing a large effect — but too few, too small, or not yet peer-reviewed for a firm answer. TRANSCEND, published in the New England Journal of Medicine in July 2026: 120 people aged 4 to 66 whose obesity followed a hypothalamic tumour, lesion or injury were randomised 2:1 to setmelanotide or placebo. BMI fell 16.5% on setmelanotide and rose 3.3% on placebo at 52 weeks, and hunger scores fell further on the drug. Serious adverse events were reported in 28% against 8%. One randomised trial, so B. Health Canada approved this use on 22 September 2026.

What the studies show

TRANSCEND, published in the New England Journal of Medicine in July 2026: 120 people aged 4 to 66 whose obesity followed a hypothalamic tumour, lesion or injury were randomised 2:1 to setmelanotide or placebo. BMI fell 16.5% on setmelanotide and rose 3.3% on placebo at 52 weeks, and hunger scores fell further on the drug. Serious adverse events were reported in 28% against 8%. One randomised trial, so B. Health Canada approved this use on 22 September 2026.

“The least-squares mean (LSM) change in BMI at 52 weeks was -16.5% (95% confidence interval [CI], -19.3 to -13.8) with setmelanotide and 3.3% (95% CI, -0.6 to 7.2) with placebo (P<0.001), and the LSM change in the weekly average of maximal daily hunger scores was -2.73 (95% CI, -3.28 to -2.18) in the setmelanotide group and -1.45 (95% CI, -2.23 to -0.67) in the placebo group (P = 0.009).”

Verbatim, from the abstractMiller JL, et al. Setmelanotide for the treatment of acquired hypothalamic obesity (TRANSCEND). N Engl J Med, 2026;395(2):138–150

Human trials exist and mostly agree, but there are too few of them, they are too small, or one big one is still reading out. Expect the grade to move.

  1. 1
    Miller JL, et al. Setmelanotide for the treatment of acquired hypothalamic obesity (TRANSCEND).N Engl J Med, 2026;395(2):138–150120 randomised 2:1, 52 weeks; BMI −16.5% vs +3.3%. NCT05774756.
  2. 2
    Rhythm Pharmaceuticals. Health Canada approval of Imcivree (setmelanotide) for weight management in adult and paediatric patients 4 years of age and older with acquired hypothalamic obesity.Press release, 22 Sep 2026Also states the 2023 Canadian approval for Bardet-Biedl syndrome and POMC, PCSK1 or LEPR deficiency. Company source.

In context

Setmelanotide is a cyclic analogue of α-MSH that activates the MC4 receptor, the brain's main satiety switch. In people whose obesity is caused by rare mutations upstream of that receptor — POMC, PCSK1 or LEPR deficiency, or Bardet-Biedl syndrome — it restores the signal: 80% of POMC-deficient and 45% of LEPR-deficient patients lost at least a tenth of their body weight in a year, with hunger scores falling by a quarter to a half. Those trials had ten and eleven participants. In obesity that follows damage to the hypothalamus, a 120-person randomised trial found BMI fell 16.5% against a 3.3% rise on placebo; Canada approved that use in September 2026. It has no role in common obesity.

Setmelanotide is approved (rx) — rare genetic obesity; hypothalamic obesity in canada. Legal status differs by country — see the regulation section or the jurisdiction pages.

Questions

Is Setmelanotide proven to help with weight loss in acquired hypothalamic obesity?
Not yet settled. 1 phase 3 RCT (TRANSCEND, n=120, 52 wk) — LYO grades it B, meaning probable but liable to change as trials read out.
What studies are behind the grade?
TRANSCEND, published in the New England Journal of Medicine in July 2026: 120 people aged 4 to 66 whose obesity followed a hypothalamic tumour, lesion or injury were randomised 2:1 to setmelanotide or placebo. BMI fell 16.5% on setmelanotide and rose 3.3% on placebo at 52 weeks, and hunger scores fell further on the drug. Serious adverse events were reported in 28% against 8%. One randomised trial, so B. Health Canada approved this use on 22 September 2026.
Is Setmelanotide approved for this?
Setmelanotide is an approved medicine (Approved (Rx) — rare genetic obesity; hypothalamic obesity in Canada); whether this particular outcome is a licensed indication is stated on the compound page's regulation section.

Other outcomes for Setmelanotide

Written and maintained by LYO Research — how pages are written and checked. Reviewed 7 October 2026. Grades count human evidence only; see how LYO grades. Not medical advice. Correct this page →