The global Phase 2b study assessing bimagrumab as a single agent and in combination with semaglutide in patients with obesity aims to evaluate its potential to substantially prevent the loss of muscle mass while reducing fat

More than 500 patients have been enrolled in the trial, which is projected to read out mid-2024 

NEW YORK, June 21st, 2023 — Versanis Bio (“Versanis”), a clinical-stage biopharmaceutical company advancing novel therapeutics for obesity and other cardiometabolic diseases, today announced that BELIEVE (NCT05616013), a global Phase 2b study in patients with obesity, has completed enrollment, with 507 patients randomized. 

The primary phase of the study will assess the safety and efficacy of bimagrumab as a monotherapy and in combination with semaglutide over 48 weeks of treatment. The study seeks to demonstrate that coadministration of bimagrumab has the potential to substantially prevent the loss of muscle mass observed with semaglutide and other incretin therapies. In preclinical experiments, coadministration of bimagrumab with incretins had an additive effect on total fat loss while preserving muscle mass. The study will continue through a second phase, with patients remaining on treatment through 72 weeks, followed by an off-treatment period to evaluate weight loss maintenance through 104 weeks.  

“Achieving our enrollment target in the BELIEVE study is an important milestone and highlights the tremendous enthusiasm for novel mechanisms that can achieve quality weight loss,” said Ken Attie, M.D., CMO of Versanis. “We remain on track for an expected top-line readout by mid-2024.”

Bimagrumab is a first-in-class monoclonal antibody that binds activin type II A and B receptors. A prior Phase 2a study assessing bimagrumab in patients with obesity and type 2 diabetes showed a 21.9% reduction in fat mass after 48 weeks of therapy while increasing lean muscle mass by 4.5%. In the same study, patients were followed for an additional 12 weeks after the last dose of bimagrumab and experienced no weight regain. In contrast, rapid weight regain has been observed in patients who stop taking semaglutide and other incretins.

“While the new generation of incretin therapies have been revolutionary for patients living with obesity, bimagrumab addresses a critical unmet need as a therapeutic that targets fat loss while building muscle mass,” said Mark Pruzanski, M.D., CEO of Versanis. “This enables patients to achieve the best weight loss quality, which we anticipate will lead to optimal metabolic health and sustained long-term benefit.”


About Bimagrumab

Bimagrumab is a first-in-class, fully human IgG1/λ monoclonal antibody to activin type II receptors that blocks binding of ligands including myostatin, activins, and GDF11. Bimagrumab treatment decreases body fat, especially abdominal visceral fat, while at the same time increasing muscle mass. Bimagrumab has been administered to more than 1,000 patients for up to 18 months across more than 20 completed clinical studies. It is now being advanced as a novel treatment for patients living with obesity, with additional indications to follow.

About Versanis

Versanis Bio is a privately held, clinical-stage biopharmaceutical company bringing transformational treatments to people living with cardiometabolic disease. The company’s lead asset, bimagrumab, is being advanced in a Phase 2b study as a novel treatment for obesity to help adults achieve high quality weight loss with substantial fat loss and increased lean muscle mass. In September 2022, the company was named to Endpoints 11, Endpoints News’ premier list of biotech’s most promising startups. For more information, please visit