Stamulumab
PMID 18335515 found a trend toward larger muscles in a small group. The trial included 116 adults. It was randomized and double-blind. Each person received MYO-029 or placebo. Muscle strength did not improve in the exploratory tests. Function did not improve in those tests. The study was not large enough to test efficacy. The authors rated safety and tolerance as good overall. Skin hypersensitivity occurred in the two highest-dose groups. PubMed lists one Medical Research Council grant and two NCRR NIH grants. Crossref lists no funder (checked 2026-08-26).
What exactly is Stamulumab?
Stamulumab is also called MYO-029. It is an antibody against myostatin (GDF-8). It is the register's only antibody-class entry (checked 2026-08-26).
| Identity field | Verified value, checked 2026-08-26 |
|---|---|
| Register name | Stamulumab |
| Register alias | MYO-029 |
| Register class | Neutralising antibody to myostatin (GDF-8) |
| GSRS substance class | Protein |
| GSRS chain structure | Two chains of 447 residues and two chains of 211 residues |
| Molecular formula | C6330H9740N1672O2000S48 |
| Estimated molecular weight | 143,000 Da |
| UNII | V43X8G4797, checked 2026-08-26 |
| CAS | 705287-60-1, checked in the same GSRS record on 2026-08-26 |
GSRS records four antibody chains. The two longer chains each have 447 residues. The two shorter chains each have 211 residues.
What did human studies measure?
| Primary record | Human sample | Measured finding | Funding and limit |
|---|---|---|---|
| PMID 18335515 | 116 adults with Becker, facioscapulohumeral, or limb-girdle muscular dystrophy | The paper reported a trend toward increased muscle size in a limited number of participants. Exploratory muscle-strength endpoints did not improve. Exploratory function endpoints did not improve. Skin hypersensitivity occurred in the two highest-dose cohorts. | PubMed lists one Medical Research Council grant and two NCRR NIH grants. Crossref lists no funder. The study was not powered to test efficacy. Checked 2026-08-26. |
| NCT00104078 | 108 adults registered | The Phase 1/2 record is completed, randomized, double-blind, and lists safety as the primary outcome. ClinicalTrials.gov posts no results for this record. | Wyeth, now a wholly owned Pfizer subsidiary, is the industry lead sponsor. The registry count is 108 rather than the paper's 116, so this page keeps the records separate. Checked 2026-08-26. |
| NCT00563810 | 72 healthy participants registered | The Phase 1 record is completed and double-blind. ClinicalTrials.gov posts no results for this record. | Wyeth, now a wholly owned Pfizer subsidiary, is the industry lead sponsor. Checked 2026-08-26. |
| PMID 19086063 | 6 participants in a muscle-fiber substudy; 5 received MYO-029 and 1 received placebo | Four of five MYO-029 participants improved in single-fiber contractile properties. Quantitative muscle-strength measurements did not improve. The placebo participant did not improve. | PubMed provides no GrantList. Crossref lists no funder. PubMed labels the paper Research Support, Non-U.S. Gov't. Checked 2026-08-26. |
| PMID 27700008 | Translational model using human and animal pharmacokinetic data | Estimated central clearance in humans was 0.38 mL/hour/kg. The authors concluded that the trial exposures had a low probability of producing robust efficacy. | Crossref lists Pfizer as funder. Two authors had Pfizer affiliations. This was a retrospective pharmacokinetic and pharmacodynamic model rather than a new treatment trial. Checked 2026-08-26. |
How strong is the evidence?
Evidence tier B applies here (checked 2026-08-26). Human Phase 1 and Phase 1/2 studies are complete. No authorised use is stored in the register.
The adult trial record lists 108 people. The paper lists 116 people. The opened sources do not resolve that difference.
The healthy-person record has no posted results. The adult trial record also has no posted results.
What do current United States product records show?
| Current source checked August 26, 2026 | Result | Boundary |
|---|---|---|
DailyMed exact Stamulumab search | No result | DailyMed listing search only |
DailyMed exact MYO-029 search | No result | DailyMed listing search only |
DailyMed UNII V43X8G4797 search | No result | DailyMed listing search only |
| openFDA Drugs@FDA exact name and UNII searches | No matching application | United States application records only |
A completed trial is not a product approval.
What do the EU and country fields show?
| Field | Current primary record |
|---|---|
Central EU status: unclear | The current EMA file contains 2,732 medicine rows. No row contains Stamulumab, MYO-029, V43X8G4797, 705287-60-1, or myostatin. Mecasermin and somatropin controls were found. The central file does not cover every national authorisation. Checked 2026-08-26. |
Germany: doping_classified | The current German source names Stamulumab directly in the category Myostatinfunktionen verändernde Stoffe. It is not printed as an example. Checked 2026-08-26. |
Sweden: unclear | The current Swedish product file contains 38,382 rows. No row contains Stamulumab, MYO-029, V43X8G4797, 705287-60-1, or myostatin. Mekasermin and somatropin controls were found. Exact-term absence does not settle classification. Checked 2026-08-26. |
EU status is one field. Evidence tier is another field. The German class is also separate.
Is there a first submitted-product observation?
The register stores first_observed: null (checked 2026-08-26).
The register gives no date for a submitted Stamulumab vial. This page does not apply peptide vial-test findings to this antibody.