What it is
Trevogrumab is not a peptide. It is a fully human monoclonal antibody, developed by Regeneron, that binds myostatin — also called GDF-8 — and stops it working.
Myostatin is the body's main brake on skeletal muscle growth. The evidence for how strong that brake is comes from animals that lack it: in the mouse work that used this antibody, mice born without myostatin carried twice the muscle mass of normal mice (Proteomics, 2017; DOI 10.1002/pmic.201600006).
It is in this library because it is searched beside muscle and GLP-1 peptides, and because it is one of a small group of drugs being tested to protect muscle during GLP-1 weight loss.
One trial by name, eight by code
This entry's first finding is about how to find it.
| Search on ClinicalTrials.gov | Studies returned |
|---|---|
| trevogrumab | 1 |
| REGN1033 | 8 (the same one included) |
Queried 2026-09-17. The eight REGN1033 records carry 1,629 planned or actual participants:
| Study | Phase | Participants | What it tested |
|---|---|---|---|
| NCT01507402 | 1 | 76 | single ascending doses, from 2012 |
| NCT01720576 | 1 | 60 | multiple ascending doses |
| NCT01910220 | 1 | 125 | safety and bioeffect |
| NCT02741739 | 1 | 28 | two formulations |
| NCT02943239 | 1 | 82 | with REGN2477 (garetosmab) |
| NCT01963598 | 2 | 253 | sarcopenia, three months, from 2013 |
| NCT03710941 | 2 | 0 | inclusion body myositis — withdrawn |
| NCT06299098 | 2 | 1,005 | COURAGE: with semaglutide in obesity |
Early records name Sanofi as collaborator and carry a second code, SAR391786. A reader, or an assistant, counting this compound's trials by its current name would miss seven of eight. This library searches the development code for exactly this reason.
What has been reported, and what has not
In mice, it builds muscle. A 2015 Skeletal Muscle paper reported that myostatin blockade with this fully human antibody induced muscle hypertrophy and reversed atrophy in young and aged mice. The 2017 Proteomics paper found two weeks of REGN1033 produced a significant 20% increase in muscle mass.
That second paper also carries the compound's most useful caution. Antibody-treated mice changed only 0.7% of 1,510 measured muscle proteins by more than 1.5-fold — close to the background difference of 0.5% — while mice born without myostatin changed 12.0%. Blocking myostatin in an adult animal is not the same as never having it, and the bigger muscle of the knockout is not what the drug delivers.
In people, no efficacy result has been published. PubMed indexes 2 records under trevogrumab and 4 under REGN1033 (E-utilities, 2026-09-17). The two primary research papers are the mouse studies above; the rest are reviews and a conference report. The 253-person sarcopenia trial is marked completed on ClinicalTrials.gov with no results posted, and no paper reporting it was found.
COURAGE: the trial that will say
The current test is COURAGE (NCT06299098, Regeneron): trevogrumab, alone or with garetosmab, given with semaglutide (Wegovy).
- Part A — healthy volunteers, trevogrumab against placebo, for safety.
- Parts B and C — people with obesity, semaglutide with trevogrumab at moderate-high or high dose, with or without garetosmab, including arms that stop or continue trevogrumab in a later phase.
- Enrolled: 1,005.
- Primary outcomes: adverse events and their severity, and percent change in total fat mass, total lean mass and body weight.
- Primary completion: 2026-06-16 (actual). No results posted on the registry when checked.
Garetosmab blocks activin A, another muscle-limiting signal. Pairing the two antibodies covers more of the pathway that bimagrumab blocks in one step at the receptor — which is the clearest way to see how these two drugs differ.
Where it stands
An investigational antibody with a long, quiet registry history, a clean mouse mechanism, no published human efficacy data, and a large trial whose primary completion date has passed without posted results. It has no approved product. What COURAGE reports on lean mass will be the first human answer to the question the compound is now searched for.
Related entries in this library: bimagrumab blocks the receptor rather than the signal; follistatin, which neutralises myostatin naturally, is the protein this antibody imitates in effect; Wegovy's active ingredient, semaglutide, is the drug it is being tested beside.
Last checked
2026-09-17. The eight ClinicalTrials.gov records (one found by name, all eight by code) were read through the ClinicalTrials.gov v2 API, and the REGN1033 papers through PubMed with the Proteomics DOI verified by content negotiation, all on that date, as were the PubMed counts.