Trevogrumab
Regeneron's anti-myostatin monoclonal antibody. The Phase 2 COURAGE trial, presented at EASD in October 2026, found it reduced the lean-mass loss seen on semaglutide.
Investigational compounds, read carefully
This section covers peptides at the frontier of research. Most entries are preclinical, in early or mid-stage clinical trials, or theoretical. Evidence levels are explicitly marked on every entry.
Nothing on these pages constitutes medical advice, dosing recommendations, or instructions for use. Many of these compounds are not commercially available; some are not legal for human use. Decisions about treatment require a qualified clinician.
At a glance
Regeneron's targeted anti-myostatin antibody pursuing the same muscle-preservation hypothesis as bimagrumab, but with selectivity for myostatin specifically rather than the shared ActRIIB receptor.
- Class
- Anti-myostatin monoclonal antibody
- Sponsor
- Regeneron Pharmaceuticals
- Stage
- Phase 2
- Lead use case
- Muscle preservation alongside GLP-1 therapy
What it is
Trevogrumab is a fully human monoclonal antibody that binds and neutralizes mature myostatin. Unlike bimagrumab (which blocks ActRIIB and therefore neutralizes both myostatin and activin signaling), trevogrumab is selective for myostatin specifically.
Current research status
The Phase 2 COURAGE trial reported its 52-week results at EASD on October 1, 2026, and the paper is in press at The Lancet. Regeneron's next step is another Phase 2 trial, in older adults with obesity and low muscle mass or strength.[3] Earlier Phase 2 work in sarcopenia and inclusion body myositis has informed the current obesity-pairing strategy.
Mechanistic rationale
Mature myostatin binds ActRIIB with another co-receptor (ALK4 or ALK5) to activate Smad2/3 signaling and suppress muscle protein synthesis. Trevogrumab binds the active myostatin ligand directly, preventing receptor engagement. The selectivity for myostatin (vs activin or other TGF-β family ligands) is the defining feature of the program.
Available evidence
COURAGE (Phase 2, adults with BMI ≥30, 52 weeks), In the lower-dose portion, trevogrumab 25 mg or 75 mg was added to semaglutide 2.4 mg. On DXA, lean mass fell 7.3% at 52 weeks on semaglutide alone, against 5.8% with 25 mg and 4.2% with 75 mg, meaning about 21% and 43% of the lean-mass loss was prevented. In an MRI substudy of thigh muscle volume, about 64% to 73% of the muscle loss was prevented, which is where the widely reported "70%" figure comes from. Trevogrumab did not meaningfully add to weight loss, and adverse events were similar to semaglutide alone (77% vs 82% of participants), mostly gastrointestinal.[3]
Earlier sarcopenia work, Phase 2 trials in older adults with sarcopenia showed modest but measurable increases in lean body mass over 24 weeks.
Why it's interesting
The myostatin-selective vs ActRIIB-blockade question is one of the more interesting unresolved scientific questions in muscle-preservation pharmacology. Bimagrumab's broader receptor blockade may produce larger effects but also broader off-target effects; trevogrumab's selectivity may produce smaller-but-cleaner effects. Whether selectivity or potency wins out clinically is a question the head-to-head data will eventually answer.
Limitations & risks
Selectivity has trade-offs. Pure anti-myostatin antibodies have historically produced smaller muscle-mass effects than broader ActRII pathway blockers in animal and human studies. Myostatin is one of several muscle-suppressing ligands, and blocking only one may leave the others active. COURAGE shows preserved lean tissue on scans; it does not yet show better strength, function, or long-term outcomes, which is what would justify adding an antibody to GLP-1 therapy.
Community discussion notes
Discussed extensively in fitness and bodybuilding communities given the long history of myostatin inhibition as a goal. The combination with semaglutide is what brought it into the mainstream metabolic-medicine conversation. Real-world use is investigational only, neither the antibody nor any equivalent grey-market product has demonstrated body-composition effects in the magnitude that fitness-community discussion sometimes implies.
The takeaway
Trevogrumab is the leading selective-anti-myostatin candidate in development for the muscle-preservation use case. Whether selectivity for myostatin specifically (vs broader ActRII-pathway blockade like bimagrumab) is the right approach remains open. COURAGE shows partial lean-mass preservation without extra weight loss, and the functional benefit still has to be demonstrated.
References
- Regeneron Pharmaceuticals. Trevogrumab Phase 2 obesity / muscle-preservation trial results. Corporate disclosures and peer-reviewed publications anticipated. https://pubmed.ncbi.nlm.nih.gov/?term=trevogrumab
- Latres E, et al. Anti-myostatin antibody increases muscle mass and strength in muscle wasting models. Skelet Muscle. 2015;5:34. https://pubmed.ncbi.nlm.nih.gov/26395986/
- Regeneron. Phase 2 COURAGE trial confirms trevogrumab prevents lean mass loss with semaglutide (presented at EASD 2026; in press, The Lancet). October 1, 2026. https://investor.regeneron.com/news-releases/news-release-details/phase-2-courage-trial-confirms-trevogrumab-prevents-lean-mass