Selective myostatin activation inhibitor
Apitegromab
Between-group difference: 1.9 kg less lean-mass loss (80% CI 1.2–2.7), with similar weight loss.
Evidence Maturity · M3 — Clinical
Investigational for obesity
Evidence reviewed: September 19, 2026Source-labeled
Evidence in context
Completer analysis, descriptive statistics and no multiplicity adjustment limit certainty. Less lean loss is not muscle gain or demonstrated functional improvement.
Study details
Doses studied — not a dosing recommendation. Regimens belong to the named study, formulation and population.
EMBRAZE randomized phase 2 trial
- Population
- 102 randomized adults; primary analysis included 87 completers with week-24 DXA.
- Doses and administration studied
- Apitegromab 10 mg/kg intravenously every four weeks plus weekly subcutaneous tirzepatide, escalated up to 15 mg, versus placebo plus tirzepatide.
- Duration
- 24 weeks
- Reported finding / status
- Between-group difference: 1.9 kg less lean-mass loss (80% CI 1.2–2.7), with similar weight loss.
- Interpretation and limitations
- Completer analysis, descriptive statistics and no multiplicity adjustment limit certainty. Less lean loss is not muscle gain or demonstrated functional improvement.
Source tier B · Read the original study or record
Outcome Evidence Strength
Weight change3/5
Fat-mass change3/5
Lean-mass change3/5
Strength / function benefit0/5
Published phase 2 measurements support a lean-preservation signal, not added weight-loss efficacy or proven function.