Head to head
Bimagrumab against Apitegromab
Two antibodies aimed at the same problem from different points on the pathway, one blocking activin receptors and one binding latent myostatin. Both have been studied alongside incretin drugs for lean mass preservation.
Column A
BimagrumabBimagrumab (anti-activin receptor antibody)
A muscle-preserving antibody that blocks activin receptors to reduce fat while increasing lean mass, being studied alongside GLP-1 drugs.
Column B
ApitegromabApitegromab (SRK-015)
An antibody against latent myostatin, under FDA review for spinal muscular atrophy (decision due September 30, 2026) and shown to preserve 55% of the lean mass otherwise lost on tirzepatide.
Side by side, on the facts we can check
| Attribute | Bimagrumab | Apitegromab |
|---|---|---|
| Category | Metabolic | Muscle & Performance |
| FDA status | Investigational for obesity / body composition; Phase 2 BELIEVE published 2026 | Under FDA review for SMA (PDUFA September 30, 2026); investigational in obesity |
| Half-life | Weeks (antibody) | Not established (antibody; monthly intravenous dosing) |
| Molecular weight | About 150 kDa (IgG1 monoclonal antibody; KEGG lists the full heavy and light chain sequences but no mass) | 144,734 Da (IgG1 monoclonal antibody) |
| Mechanism | Blocks activin type II receptors, neutralizing myostatin and activin signaling to build muscle and reduce fat mass. | Monoclonal antibody that binds pro/latent myostatin and prevents its activation, increasing skeletal muscle mass. |
| Human studies cited | 2 | 2 |
| Legal status, US | Investigational, not approved | Investigational, not approved |
Frequently asked questions
What is the difference between Bimagrumab and Apitegromab?
Bimagrumab: A muscle-preserving antibody that blocks activin receptors to reduce fat while increasing lean mass, being studied alongside GLP-1 drugs. Apitegromab: An antibody against latent myostatin, under FDA review for spinal muscular atrophy (decision due September 30, 2026) and shown to preserve 55% of the lean mass otherwise lost on tirzepatide.
Which has stronger research evidence, Bimagrumab or Apitegromab?
This database does not grade compounds. It counts what was run in people: 2 of the 2 studies cited on the Bimagrumab profile were human work, against 2 of 2 for Apitegromab. Those counts are of our own citation lists and understate any larger literature, and neither is a recommendation.
Are Bimagrumab and Apitegromab FDA-approved?
Bimagrumab: Investigational for obesity / body composition; Phase 2 BELIEVE published 2026. Apitegromab: Under FDA review for SMA (PDUFA September 30, 2026); investigational in obesity.
Related posts
Blog articles that cover Bimagrumab or Apitegromab, newest first.
Reviewed Sep 2026. This page sets two published records side by side. It is educational, it is not medical advice, and it contains no dosing protocols or recommendations for personal use.