GSK to expand hepatology pipeline with potential best-in-class therapy

GSK has agreed to acquire Boston Pharmaceuticals’ lead asset, efimosfermin alfa, for up to $2 billion. The Phase III-ready injectable drug has best-in-class potential to treat and prevent progression of steatotic liver disease (SLD). Efimosfermin is a once-monthly fibroblast growth factor 21 (FGF21) analog therapeutic with a direct antifibrotic mechanism of action, GSK explained.

Further details about GSK and Boston Pharmaceuticals’ new deal

Through the agreement, GSK will acquire BP Asset IX, Inc., a subsidiary of Boston Pharmaceuticals, providing the pharmaceutical company with rights to efimosfermin as a treatment for liver disease.

GSK will pay $1.2 billion upfront, then up to $800 million, dependent on success of achievement of certain developmental milestones. The pharmaceutical company will also be responsible for tiered royalties owed to Novartis Pharma AG.

Potential of efimosfermin in the liver disease MASH

Recent Phase II trial data in moderate-to-advanced (F2 or F3) metabolic dysfunction-associated steatohepatitis (MASH), showed that the treatment rapidly and significantly reversed liver fibrosis and halted disease progression, alongside offering a manageable tolerability profile, GSK stated.

This indicates that efimosfermin could provide greater fibrosis improvement compared to other therapies. In addition, the treatment could reduce triglyceride levels and improve glycaemic control, offering benefit to MASH patients with cardiometabolic co-morbidities, the company added.

Full data from the trial was presented at the American Association for the Study of Liver Diseases (AASLD) Meeting in late 2024.

“The FGF21 class has shown some of the most exciting data in MASH including first-in-disease evidence of cirrhosis reversal, and efimosfermin has the potential to define a new standard-of-care with its monthly dosing and tolerability profile.

“Efimosfermin will significantly expand our hepatology pipeline and provide us the opportunity to develop a new potential best-in-class medicine with first launch expected in 2029. It complements GSK‘990, also in development for ALD and MASH, offering GSK options to develop both monotherapy and potential combinations to improve patient outcomes,” shared Tony Wood, Chief Scientific Officer, GSK.

Closing of this new deal is subject to customary conditions.

In January, GSK also announced a billion-dollar acquisition for another potential best-in-class therapy.