Swiss pharmaceutical giant Roche announced today a definitive merger agreement to acquire 89bio, Inc. for up to $3.5 billion, gaining access to pegozafermin, a late-stage fibroblast growth factor 21 (FGF21) analog in Phase III development for metabolic dysfunction-associated steatohepatitis (MASH). The transaction represents Roche's strategic expansion into cardiovascular, renal, and metabolic diseases, targeting one of obesity's most prevalent comorbidities.
Deal Structure and Financial Terms
Under the agreement, Roche will pay $14.50 per share in cash at closing, representing a total equity value of approximately $2.4 billion and a 52% premium over 89bio's 60-day volume-weighted average price on September 17, 2025. Shareholders will also receive non-tradeable contingent value rights (CVRs) worth up to $6.00 per share, bringing the total potential deal value to $3.5 billion.
The CVR structure includes three milestone-based payments: $2.00 per share upon first commercial sale of pegozafermin in F4 MASH cirrhosis by March 2030, $1.50 per share when annual net sales reach $3.0 billion globally by December 2033, and $2.50 per share when annual sales hit $4.0 billion globally by December 2035. If achieved, these payments would represent up to $1.0 billion in additional consideration for 89bio stockholders.
Pegozafermin's Therapeutic Profile
Pegozafermin is a glycoPEGylated FGF21 analog currently in Phase III clinical trials for patients with moderate and severe MASH fibrosis (F2 and F3 stages) and cirrhosis (F4 stage). The drug mimics the endogenous hormone FGF21, a regulator of energy and lipid metabolism, by binding to FGF receptors in complex with the co-receptor β-Klotho to enhance fatty acid oxidation, reduce hepatic fat accumulation, and improve insulin sensitivity.
"With its combined anti-fibrotic and anti-inflammatory mechanism, pegozafermin could potentially offer best-in-disease efficacy for all moderate to severe MASH patients," said Thomas Schinecker, Roche Group CEO. The compound is designed to combine anti-fibrotic and anti-inflammatory activity with a favorable safety profile, positioning it as a potentially transformative treatment option.
Market Opportunity and Competitive Landscape
MASH affects an estimated 5-7% of the global adult population, with more than 75% of patients living with comorbidities such as obesity and type 2 diabetes. According to IQVIA data cited in the announcement, the United States will have an estimated 14 million patients with F2-F4 MASH by 2030. GlobalData reported that drug sales for MASH across the seven major markets reached approximately $802.3 million in 2022, with the US MASH pharmacotherapy opportunity expected to reach multi-billion-dollar scale as treatment options and diagnosis rates expand.
The competitive landscape includes several companies advancing treatments in Phase III trials. Novo Nordisk reported from the Phase III ESSENCE trial that semaglutide 2.4 mg achieved resolution of steatohepatitis without worsening of fibrosis in 62.9% of patients versus 34.3% on placebo, and fibrosis improvement without worsening of steatohepatitis in 36.8% versus 22.4%. Boehringer Ingelheim and Zealand Pharma reported from a Phase II trial that survodutide achieved steatohepatitis resolution without worsening of fibrosis in 47-62% of patients versus 14% on placebo.
Akero Therapeutics is also developing efruxifermin, another FGF21 analog, in Phase III trials, though no Phase III efficacy results have been published. FGF21 analogues offer advantages including broad metabolic benefits and anti-fibrotic activity, though limitations include injection-based administration and challenges with long-term tolerability.
Strategic Integration
Roche plans to integrate pegozafermin into its cardiovascular, renal and metabolic (CVRM) portfolio and explore combination development with incretins. "This acquisition further strengthens our portfolio in cardiovascular, renal, and metabolic diseases and offers opportunities to explore combinations with existing programmes in our pipeline," Schinecker noted.
Current 89bio employees will join the Roche Group as part of Roche's Pharmaceuticals Division. The transaction is expected to close in the fourth quarter of 2025, subject to customary closing conditions including the tender of at least a majority of outstanding shares and regulatory approvals.
The merger agreement has been unanimously approved by the boards of both companies, with 89bio's board recommending that stockholders tender their shares pursuant to the tender offer.
