Bimagrumab
Chemical compound
From Wikipedia, the free encyclopedia
Bimagrumab (BYM338) is a human monoclonal antibody first developed by Novartis[1] and currently by Eli Lilly to treat pathological muscle loss and weakness. It binds to and inhibits activin receptor type-2B.[2]
| Monoclonal antibody | |
|---|---|
| Type | ? |
| Source | Human |
| Target | ACVR2B |
| Clinical data | |
| Other names | BYM338 |
| Routes of administration | Intravenous |
| ATC code |
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| Identifiers | |
| CAS Number | |
| ChemSpider |
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| UNII | |
| KEGG | |
| Chemical and physical data | |
| Formula | C6306H9732N1684O1990S46 |
| Molar mass | 142451.78 g·mol−1 |
Bimagrumab must be administered intravenously at a hospital or clinic. The medication has a long half-life and is administered once a month.[3]
Development history
Bimagrumab was developed by Novartis, in collaboration with Morphosys.[1] On August 20, 2013, it was announced that bimagrumab had received a breakthrough therapy designation for sporadic inclusion body myositis (sIBM) by the US Food and Drug Administration (FDA).[1]
In 2014, Bimagrumab entered Phase II development, with some research indicating clinical effects.[4] Novartis planned to apply in 2016 for FDA approval to treat sIBM patients with bimagrumab.[5]
In April 2016, Novartis announced that bimagrumab had failed a Phase IIb/III study for sporadic inclusion body myositis.[6] In January 2021, a new study confirmed that treatment with bimagrumab is safe and effective for treating excess adiposity and metabolic disturbances of adult patients with obesity and type 2 diabetes.[7] Novartis then licensed the drug to Versanis Bio, a Medicxi Fund and Atlas Venture-backed startup, who closed a series A financing round to fund a phase II clinical program targeting weight loss in obese patients.[8][9] In January 2023 Versanis Bio entered the medication into phase IIb trials for obesity.[3] In July 2023, Eli Lilly bought Versanis Bio for their weight loss asset for $1.9 billion.[10]
In 2025, a phase IIb study was concluded testing bimagrumab in combination with Novo Nordisk's semaglutide, demonstrating that the combination resulted in a greater loss of fat as a percentage of weight compared to semaglutide alone.[11][12] In September 2025, Eli Lilly terminated a phase IIb study investigating a tirzepatide-bimagrumab combination in obese and type II diabetic patients.[13][14] As of March 2026[update], a third phase IIb study of tirzepatide and bimagrumab in combination is ongoing.
