HQ Team
May 14, 2025: GSK Plc will acquire Boston Pharmaceutical’s investigational lead asset, efimosfermin alfa, to treat serious liver diseases, for $2 billion in cash.
GSK will pay $1.2 billion upfront and $800 million after reaching certain milestones for the drug, which is on an end-stage trial to treat and prevent the progression of steatotic liver disease, according to a company statement.
GSK will acquire BP Asset IX, Inc., a subsidiary of Boston Pharmaceuticals, to access efimosfermin.
The drug further strengthens GSK’s hepatology pipeline of speciality medicines aimed at addressing both viral (chronic hepatitis B) and steatotic drivers of fibrotic liver diseases.
Fat buildup
Efimosfermin is being developed to treat serious liver problems caused by fat buildup and inflammation in the liver, known as metabolic dysfunction-associated steatohepatitis (MASH).
MASH is a severe form of fatty liver disease that can lead to liver scarring (cirrhosis) and liver failure. Efimosfermin works by directly stopping the scarring process in the liver. It is designed to be taken once a month.
This drug is also being looked at for treating liver damage caused by alcohol. Because it targets the scarring directly, it might help patients with more advanced liver disease.
There is also a plan to use efimosfermin together with another experimental treatment called GSK’990, which works differently, to help more people with liver disease.
Limited therapeutic options
“The acquisition of efimosfermin is highly aligned to GSK’s research and development focus on science related to the immune system and is further evidence of the company’s intent to build on its deep understanding of fibrosis and auto-inflammation to develop precision interventions that stop and reverse disease progression,” according to the statement.
Steatotic liver disease is an area of significant unmet medical need affecting approximately 5% of the global population, with limited therapeutic options for patients.
Alcoholic liver disease affects about 26 million patients globally, and together with MASH, is the leading cause of liver transplant in the US.
Substantial and disproportionate costs are associated with end-stage liver disease. Interventions that reduce moderate-to-advanced fibrosis to prevent progression of cirrhosis, liver cancer, hospitalisations, and transplant could save the US healthcare system between $40 and 100 billion over the next two decades.
Triglyceride reduction
Recent data from a phase II trial of efimosfermin showed that it rapidly and significantly reversed liver fibrosis and stopped its progression, with a “manageable tolerability profile.”
These data suggest potentially greater fibrosis improvement compared to that seen with other therapeutic approaches and with benefit expected independent of background glucagon-like peptide-1 (GLP-1) therapy.
In addition, efimosfermin could offer triglyceride reduction and improved glycaemic control, important considerations for MASH patients who frequently face cardiometabolic co-morbidities.
The trial results so far have 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,” said Tony Wood, Chief Scientific Officer of GSK.
“Efimosfermin will significantly expand our hepatology pipeline and provide us the opportunity to develop a new potential best-in-class medicine with the first launch expected in 2029,” he said.
