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Peptide Evidence Registry

Metabolic & endocrine

Trevogrumab

An investigational myostatin-blocking antibody with controlled Phase 2 data on DXA-measured lean mass and MRI-measured thigh fat-free muscle volume alongside semaglutide, but no proven functional outcome.

L4Good human trialsIn clinical trialsIn clinical developmentBiologic / other
How settled this rating is:
moderate confidence in the current evidence rating
Routes studied:
Subcutaneous injection
Also known as:
REGN1033, anti-GDF8 antibody, anti-myostatin antibody
Last reviewed:
2026-10-02
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Evidence passport

Trevogrumab

A one-screen evidence identity for this compound. These fields describe research maturity, confidence and legal status. They are not a safety guarantee, efficacy percentage or recommendation.

Reviewed 2026-10-02
Evidence level
L4Good human trials
Confidence
Moderate confidence in rating
Regulatory status
In clinical trials
Development status
In clinical development

Evidence strength

Human efficacy evidence62 of 100 evidence strength

Higher = more and better-quality human evidence. It does not mean the effect is bigger or that the compound works for you.

Human safety evidence38 of 100 evidence strength

Higher = more mature, better-documented human safety data. It does not mean the compound is safer than one with a lower number.

The 0-100 values rate the strength and maturity of evidence, not how effective or safe the compound is.

Evidence base
Includes human studies
Furthest established stage
Phase II
Human research maturity
Completed controlled Phase 2 body-composition trial; sponsor-reported 52-week findings presented at EASD 2026 and described as in press
Source curation
Sources fully curated

Routes recorded

SC injection

Overview

Human efficacy evidence strength62 of 100 evidence strength

Higher = more and better-quality human evidence. It does not mean the effect is bigger or that the compound works for you.

Preclinical (animal / lab) evidence strength68 of 100 evidence strength

Higher = more animal, tissue or cell research. Preclinical results are a starting point, not proof of a human benefit.

Human safety evidence strength38 of 100 evidence strength

Higher = more mature, better-documented human safety data. It does not mean the compound is safer than one with a lower number.

Evidence for the assessed benefit

L4Good human trialsModerate confidence in rating

Controlled Phase 2 evidence supports reduced loss of DXA-measured lean mass and MRI-measured thigh fat-free muscle volume during semaglutide-associated weight loss. DXA lean mass is not synonymous with skeletal muscle, and neither measurement establishes strength, power, mobility, falls, frailty, disability, muscle quality or long-term clinical benefit.

Human research context: Adults with obesity receiving semaglutide in COURAGE; the 52-week lower-dose comparison was reported by the sponsor, presented at EASD 2026 and described as in press with The Lancet as of 1 October 2026.

Research maturity, benefit evidence, safety and approval are different questions.

How to read these scores

Every number here rates the evidence, not the compound. They are editorial 0-100 strength ratings, not percentages, and not a rating out of five stars.

  • Human efficacy evidence strength — Higher = more and better-quality human evidence. It does not mean the effect is bigger or that the compound works for you.
  • Preclinical evidence strength — Higher = more animal, tissue or cell research. Preclinical results are a starting point, not proof of a human benefit.
  • Human safety evidence strength — Higher = more mature, better-documented human safety data. It does not mean the compound is safer than one with a lower number. A score of 80 does not mean “80% safe”.
  • Evidence level (L0-L5) — the strongest type of study behind the compound, from anecdote (L0) to large replicated human trials (L5). It is a description of the study evidence, not a quality, safety or recommendation rating.
  • Confidence — how likely we think it is that this rating changes as new research lands. Low confidence means the picture is unsettled, not that the compound is bad.

None of these ratings is medical advice, a safety guarantee, or a recommendation to use anything. How we grade evidence.

How far human research has progressed: Completed controlled Phase 2 body-composition trial; sponsor-reported 52-week findings presented at EASD 2026 and described as in press

Routes & formulations

Studied / approved routes

SC injection

COURAGE studied trevogrumab by subcutaneous injection alongside semaglutide. This describes the trial route, not an approved regimen or advice for use.

Route availability is not evidence of efficacy, and evidence from one route does not transfer to another. The Registry never provides dosing or sourcing information.

Peptide lifecycle

  1. Discovery

  2. Preclinical

  3. Phase I

  4. Phase II

    Furthest established stage

  5. Phase III

  6. Approved

In clinical development

Active clinical development. The sponsor plans another Phase 2 study with GLP-1-based therapy in older adults with obesity and reduced muscle mass and/or strength.

Last documented development: 1 October 2026 — 52-week COURAGE Phase 2 results reported by Regeneron and presented at EASD

What it is

A fully human monoclonal antibody that blocks myostatin, also called growth differentiation factor 8 (GDF8). Myostatin normally restrains skeletal-muscle growth; blocking it is being tested for effects on measured body-composition compartments during weight reduction.

What people claim

  • Reduces loss of DXA-measured lean mass during GLP-1-associated weight loss
  • Reduces loss of MRI-measured thigh fat-free muscle volume during semaglutide treatment
  • Prevents frailty or improves strength and mobility

What the evidence actually says

COURAGE provides controlled Phase 2 evidence for body-composition measurements, not proof of better physical function. At week 52, DXA-measured lean mass changed by -7.3% with semaglutide alone, -5.8% with trevogrumab 25 mg plus semaglutide and -4.2% with 75 mg plus semaglutide; from those trial results, Regeneron calculated relative estimates of 20.5% and 42.5% less lean-mass loss. In a predefined MRI substudy, thigh fat-free muscle volume changed by -1.03 with semaglutide alone, -0.29 with 25 mg and -0.32 with 75 mg; the sponsor-derived relative estimates were 71.8% and 68.9% less loss. DXA lean mass is a whole-body compartment estimate that includes water, organs and other non-fat tissue and is not synonymous with skeletal muscle. MRI thigh fat-free muscle volume is anatomically more specific but remains an imaging measurement, not a functional outcome. These findings do not establish strength, power, mobility, falls, frailty, disability, muscle quality or long-term clinical benefit. They remain sponsor-reported, were presented at EASD 2026 and were described as in press with The Lancet; they should not be treated as peer reviewed unless the article is published.

Related evidence

Useful next reads based on this compound — not recommendations.

Human evidence

  • COURAGE lower-dose portion: controlled 52-week Phase 2 comparison of trevogrumab 25 mg or 75 mg plus semaglutide against semaglutide alone in adults with obesity.
  • At week 52, mean DXA-measured lean-mass change was -7.3% with semaglutide alone, -5.8% with 25 mg trevogrumab plus semaglutide and -4.2% with 75 mg plus semaglutide. Derived from those absolute observed changes, the sponsor reported relative estimates of 20.5% and 42.5% less lean-mass loss, respectively.
  • In the predefined MRI substudy, week-52 mean change in thigh fat-free muscle volume was -1.03 with semaglutide alone, -0.29 with 25 mg trevogrumab plus semaglutide and -0.32 with 75 mg plus semaglutide; derived from those observed changes, the sponsor calculated relative estimates of 71.8% and 68.9% less loss.
  • DXA lean mass includes water, organs and other non-fat tissue as well as muscle and is not synonymous with skeletal muscle. MRI thigh fat-free muscle volume is anatomically more specific, but an imaging measurement is not a functional outcome.
  • No result in the cited release establishes better strength, power, mobility, fall risk, frailty, disability, muscle quality or long-term clinical outcomes.
  • Earlier 26-week COURAGE findings also included a semaglutide, trevogrumab and garetosmab triplet arm. Those historical results remain separate: the 1 October 2026 release does not report a new 52-week triplet result.

Preclinical evidence

  • Myostatin inhibition has an established mechanistic and animal evidence base for increasing or preserving skeletal-muscle mass, but model-system findings do not establish a functional benefit in people with obesity.

Animal and cell findings are Level 1–2 evidence.

Mechanism and pathways

  • Trevogrumab binds myostatin (GDF8), reducing signalling that normally limits skeletal-muscle growth.
  • The intended effect in COURAGE was to alter the composition of semaglutide-associated weight loss, not to replace semaglutide's appetite and weight effects.
  • Reduced loss in a measured tissue compartment does not by itself demonstrate preserved muscle quality or function.

Safety and unknowns

  • Regeneron reported at least one adverse event in 77% of lower-dose trevogrumab participants versus 82% with placebo in the 52-week portion; common events included nausea, constipation, diarrhoea and vomiting in a study where participants also received semaglutide.
  • The study is too limited to establish long-term safety or uncommon risks.
  • The earlier triplet arm had more discontinuations due to tolerability issues and other adverse events; that cannot be assigned to trevogrumab alone and is not a new 52-week triplet finding.

Cancer relevance

This section covers questions raised by how the compound works in the body, plus anything regulators and trial teams keep an eye on. It is not a statement that this compound causes cancer — for most compounds here, no human data exist in either direction.

Monitored in trials; not demonstrated in humans

No human cancer effect is established. Myostatin-pathway intervention changes growth signalling in muscle, so longer and larger safety datasets remain necessary rather than assuming risk or protection.

Regulatory status

Regulatory decisions apply to specific jurisdictions, products, formulations and indications. An approval elsewhere is not automatically an approval in your country.

Check the regulatory note and linked primary sources for jurisdiction-specific details.

Investigational, with no regulatory approval for any indication. Regeneron reported 52-week Phase 2 COURAGE results on 1 October 2026 and says a further Phase 2 trial is planned in older adults with obesity and reduced muscle mass and/or strength. A planned trial is not evidence of benefit.

Key study types

  • L4Good human trialsCOURAGE lower-dose 52-week Phase 2 comparison

    Controlled Phase 2 trial; sponsor-reported at EASD 2026 and described as in press — Adults with obesity receiving semaglutide

    Reduced loss of DXA-measured lean mass and MRI-measured thigh fat-free muscle volume. The sponsor-derived relative estimates accompany the absolute observed changes in the profile; neither measurement establishes strength, power, mobility, falls, frailty, disability, muscle quality or long-term clinical benefit.

Evidence grade

L4Good human trialsModerate confidence in rating

Completed, adequately informative controlled human trials supporting a specified outcome; replication and longer-term safety may remain uncertain.

What would change our rating?

  • Publication of the full peer-reviewed COURAGE report, including analysis methods, missing-data handling and complete safety results.
  • Controlled evidence that body-composition differences translate into strength, mobility, falls, frailty or other patient-important outcomes.
  • Replication in older adults or people with low muscle mass or strength, with longer follow-up.

References and sources

Source transparency

A provenance snapshot of this profile. Counts show what kinds of sources are cited, not how much scientific weight each source deserves.

Sources fully curated
Last editorial review
2026-10-02
Recently reviewed · 14 days ago
Linked curated sources
2
Sources still pending
0
External specialist reviews
0
None recorded for this profile
Sponsor / official: 2

Review provenance

Registry editorial review: Colin Jackson-White, creator and editor, who is not a doctor or clinician. External specialist review is credited only when a named reviewer has completed a review of this exact profile.

Current linked evidence is sponsor-only. Treat findings as provisional until independent or peer-reviewed documentation is available.

Literature-discovery and AI tools may help locate or challenge candidate evidence, but they are not counted as evidence sources here. Registry judgements are tied to the underlying papers, trial records, regulator documents and official study records.

Source hierarchy: regulatory documents and trial registries first, peer-reviewed work next, sponsor material flagged as non-independent. We never use supplier or clinic marketing as evidence, and where a verified source has not yet been curated we say so rather than inventing one.

Evidence change history

These entries record changes to our assessment of the published evidence — not changes to the compound itself.

  1. Added Regeneron's 52-week controlled Phase 2 COURAGE results: DXA-measured lean mass changed by -7.3% with semaglutide alone, -5.8% with trevogrumab 25 mg plus semaglutide and -4.2% with 75 mg plus semaglutide. In the predefined MRI substudy, thigh fat-free muscle volume changed by -1.03, -0.29 and -0.32, respectively; the sponsor derived relative estimates of 71.8% and 68.9% less loss for the trevogrumab groups.

    Change 1 of 1
    L4Good human trials
    Added at L4 for specified body-composition measurements supported by a controlled Phase 2 trial. DXA lean mass is not synonymous with skeletal muscle; MRI thigh fat-free muscle volume is anatomically more specific but is not a functional outcome. The findings were sponsor-reported, presented at EASD 2026 and described as in press, not yet peer reviewed. They do not establish strength, power, mobility, falls, frailty, disability, muscle quality or long-term clinical benefit. The earlier triplet arm remains historical 26-week context, not a new 52-week result. Reviewed 2 October 2026.