GSK plc has announced the completion of its previously announced acquisition of efimosfermin alfa from Boston Pharmaceuticals. Efimosfermin is a phase III-ready, potential best-in-class investigational specialty medicine aimed at treating and preventing the progression of SLD.

GSK has acquired BP Asset IX, Inc., a subsidiary of Boston Pharmaceuticals, to access efimosfermin. The total cash consideration for this acquisition amounts to up to USD 2 billion, comprising an upfront payment of USD 1.2 billion and up to USD 800 million in success-based milestone payments. GSK will also be responsible for success-based milestone payments as well as tiered royalties for efimosfermin owed to Novartis Pharma AG.

Efimosfermin is a novel, once-monthly fibroblast growth factor 21 (FGF21) analog therapeutic in clinical development for the treatment of metabolic dysfunction-associated steatohepatitis (MASH), including cirrhosis, and future development in alcohol-related liver disease (ALD), both forms of SLD. Currently, MASH and ALD have limited treatment options and are the leading causes of liver transplant in the US, representing a significant burden and cost on healthcare utilisation.

GSK, based on its work in human genetics and disease phenotyping, believes efimosfermin has potential to address more advanced stages of SLD due to its direct antifibrotic mechanism of action, and sees opportunity in combination with GSK’990, a siRNA therapeutic in development for other subsets of patients with SLD.

Kaivan Khavandi, SVP and Global Head, Respiratory, Immunology and Inflammation R&D, GSK said, “The close of our acquisition for efimosfermin alfa represents a significant expansion of our hepatology pipeline aimed at addressing steatotic and viral drivers of liver disease. Efimosfermin is a key growth opportunity for GSK with multiple development options and potential first launch in 2029. We look forward to unlocking the potential of this medicine for patients.”

GSK is driving innovation for a range of immune-mediated conditions by harnessing the science of the immune system and advanced technologies. The addition of efimosfermin further expands GSK's pipeline to address fibro inflammatory diseases in liver, lung and kidney, a key focus for the company.