AmericanPeptide
Catalog/Emugrobart

Emugrobart

Also known as GYM-329 · RG6237 · RG-70240

A "sweeping" anti-myostatin antibody (Roche/Chugai) that not only blocks but actively clears myostatin — a cautionary case after its rare-disease trials failed.

Overview

Emugrobart is a humanized IgG1 monoclonal antibody developed by Chugai and Roche, and it is the most mechanistically distinctive entry on the myostatin axis. Beyond binding pro- and latent myostatin to block their activation, it uses a "sweeping antibody" design: pH-dependent binding that ferries captured myostatin into cells for degradation and then releases it, recycling the antibody to capture more. The intent is not just to block myostatin but to actively lower its levels.

Background

Emugrobart is also the catalog’s clearest honest-evidence cautionary tale. Its lead muscular-disease programs failed: in March 2026, Roche/Genentech discontinued development in spinal muscular atrophy (SMA) and facioscapulohumeral muscular dystrophy (FSHD) after the MANATEE trial showed no consistent benefit over risdiplam monotherapy. Notably, the company stated that the scientific rationale in obesity remained, and the Phase 2 obesity program was set to continue.

That split — a failed rare-disease readout but a continuing metabolic program — is exactly the kind of nuance a credible reference should carry, against the marketing that treats every "myostatin antibody" as a guaranteed muscle-builder. Emugrobart is an investigational antibody (~150 kDa); its sweeping-clearance design is its scientific signature.

Mechanism

Binds pro/latent myostatin to prevent activation, and via pH-dependent (recycling/sweeping) engineering accelerates clearance of bound myostatin — reducing the circulating pool rather than only neutralizing it in place.

Key research findings

  • Sweeping/recycling design — pH-dependent binding actively clears myostatin rather than only blocking it.
  • MANATEE failure — discontinued in SMA and FSHD (March 2026) after no consistent benefit over risdiplam.
  • Obesity program continued — the metabolic rationale was retained even as rare-disease use was dropped.
  • Pro/latent myostatin target — binds the inactive precursor forms.
  • Investigational — not FDA-approved.

How Emugrobart is made

Behind every vial of Emugrobart is the same exacting pipeline every research peptide runs — but the chemistry plays out differently for this molecule. Here is how Emugrobart, specifically, is brought into being.

  1. On paper first

    On paper, Emugrobart weighs in at roughly 150,000 daltons. Before a single bond is made, the target sequence, salt form, and purity threshold are written down as the contract the finished material must meet.

  2. Built residue by residue

    Emugrobart is assembled by solid-phase peptide synthesis — the chain grows one protected residue at a time on resin, and what you fail to build cleanly here you pay to remove later.

  3. Purity is won here

    The crude mixture — Emugrobart plus its deletions and side products — is then separated on preparative HPLC, and where the cut is taken decides the difference between a genuinely pure peptide and a barely-passable one.

  4. Proven, then protected

    A real batch of Emugrobart proves itself: identity confirmed by mass spectrometry against its ~150,000 Da, purity read directly off an analytical HPLC trace, water and counterion content measured. That batch-specific certificate of analysis is the only honest way to know what is actually in a vial of Emugrobart — and a short, cold, accountable chain of custody is how that purity survives the trip to your bench.

Walk the full synthesis pipeline

Handling, storage & why purity is hard

Emugrobart is a humanized IgG1 monoclonal antibody (~150 kDa) produced in mammalian cell culture, engineered for pH-dependent recycling. Characterization is antibody-grade (glycan/charge-variant profiling, mass spectrometry, binding/potency bioassay) — not a synthetic peptide.

Storage
Stored refrigerated (2–8 °C), protected from light and freezing, not shaken; investigational handling per trial protocol.
Handling
A large glycosylated antibody sensitive to freezing, heat, and agitation, which can cause aggregation.

Don't judge a vial by its cake. A fluffy, good-looking lyophilized powder reflects bulking agents and freeze-drying parameters — not purity. Insist on a batch-specific certificate of analysis.

How peptides are made — the full pipeline

Research areas

  • Spinal muscular atrophy
  • FSHD
  • Obesity
  • Muscle preservation

Research-area guides

Frequently asked questions

What is emugrobart?+

A Roche/Chugai anti-myostatin antibody (GYM-329) with a "sweeping" design that actively clears myostatin. It was studied in muscular diseases and obesity.

What happened in its trials?+

Its spinal muscular atrophy and FSHD programs were discontinued in March 2026 after the MANATEE trial showed no consistent benefit over standard therapy; the obesity program was reported to be continuing.

Is this medical advice?+

No — this is a research and educational reference. Emugrobart is an investigational antibody, not an approved drug.

Related peptides