Lilly agrees to acquire Versanis Bio for up to $1.925 billion

Eli Lilly and Company announced on July 14, 2023, that it agreed to acquire Versanis Bio, a private biotech company, in a deal worth up to $1.925 billion ^[1]. The acquisition officially closed a month later, on August 14, 2023 ^[2].

Versanis' main product is bimagrumab, a lab-made antibody that blocks activin type II A and B receptors ^[1]. These receptors control activin and myostatin, two proteins that limit muscle growth ^[1]. By blocking them, bimagrumab is designed to help the body hold onto muscle while losing fat ^[1].

At the time of the deal, bimagrumab was being tested in a mid-stage trial called BELIEVE, both by itself and combined with semaglutide, in adults who are overweight or living with obesity ^[1][2]. Lilly executives said pairing an incretin drug like semaglutide or the company's own tirzepatide with an activin blocker like bimagrumab could help patients lose fat while keeping more muscle mass than they would with incretin therapy alone ^[1][2].

The payment structure includes an upfront amount plus additional payments tied to development and sales milestones, which is why the total could reach $1.925 billion but is not guaranteed to hit that figure ^[1][2]. Lilly said it would determine under standard accounting rules whether to treat the purchase as a business combination or an asset acquisition, a decision that could affect how the deal shows up in its financial results ^[1].

Why it matters for patients

GLP-1 drugs like Ozempic, Wegovy, and Zepbound cause significant weight loss, but part of that lost weight can come from muscle, not just fat ^[1][2]. Losing muscle along with fat is a concern for some patients, especially as they age or lose large amounts of weight. Lilly's interest in bimagrumab reflects an industry effort to address that side effect by testing drugs that might protect muscle during weight loss treatment ^[1][2].

It is important for patients to understand this is still experimental. Bimagrumab combined with semaglutide was only in a Phase 2b trial at the time of this deal, meaning it had not been proven safe and effective in large, late-stage studies, and it was not close to being available by prescription ^[1][2]. The sources do not say when or whether bimagrumab plus semaglutide will reach a pharmacy shelf, what side effects the combination might cause, or how it would compare to taking semaglutide alone.

The price tag also says something about how much drug companies are willing to invest in solving the muscle-loss issue tied to popular obesity drugs. Ruth Gimeno, a Lilly research executive, said combining incretins with activin receptor blockers "could be the next major step" in treating cardiometabolic diseases such as obesity ^[2]. That kind of statement signals where the company sees its obesity drug pipeline heading, even though the actual patient benefit remains unproven.

What happens next

The sources provided do not include specific dates for when BELIEVE trial results were expected or released, so those results and any next steps in bimagrumab's development are not yet known from this material. Patients interested in muscle preservation alongside GLP-1 therapy will need to watch for later trial data and any regulatory filings, none of which appear in these announcements.