Following last week’s post on the slow activity in M&A in 2025 so far (Sivan-Consulting), we now have some activity picking up, as GSK has agreed to acquire efimosfermin from Boston Pharmaceuticals for up to $2 billion (Biopharmadive).
This transaction includes a $1.2 billion upfront payment and up to $800 million in milestone-based payments. Efimosfermin, is a long-acting FGF21 analog, that is poised to enter Phase III trials for treating steatotic liver disease (SLD), specifically targeting MASH.
Interestingly, efimosfermin’s journey began with Novartis, which licensed the drug to Boston Pharmaceuticals five years ago. This raises the question: What has changed in the past five years to make efimosfermin a valuable asset now?
The Evolution of Efimosfermin
Efimosfermin is designed as a once-monthly injection that aims to reduce liver fat, inflammation, and fibrosis—key factors in the progression of MASH. MASH (or NASH as it was known until 2023) has been a notable graveyard of failures (Nature).
Efimosfermin showed promising results in a phase II trial, with data published last November (Pubmed). These outcomes included rapid fibrosis reduction with manageable side effects, positioning it as a potential best-in-class therapy in the MASH treatment landscape.
GSK’s Strategic Alignment
GSK’s acquisition of efimosfermin aligns with its broader strategy to build a robust liver disease portfolio (GSK). The company is also developing the siRNA therapeutic GSK’990 for both MASH and alcohol-related liver disease (GSK).
Additionally, GSK has partnered with Wave Life Sciences and Arrowhead Pharmaceuticals, focusing on RNA-based therapies for liver diseases (Biopharmadive, Biopharmadive).
Acquiring efimosfermin complements these efforts, in a classic “shots on target” approach to treating difficult diseases. This could potentially allow GSK to offer standalone and combination therapies in the future.
Novartis’s Shift Away from MASH
Now on to Novartis, why did it get rid of efimosfermin?
The company had previously invested in several MASH-related assets, as many big pharma companies had done over the last ten years. Novartis licensed efimosfermin to Boston Pharmaceuticals in 2020 when it underwent a strategic realignment, and saw an opportunity to retain some upside if efimosfermin was a success whilst reducing its need to focus on developing the drug.
Novartis then continued to withdraw from targeting MASH:
- Tropifexor: An FXR agonist developed in collaboration with Allergan. Despite initial promise, Novartis discontinued its development in 2021 (Novartis.com)
- PLN-1474: A candidate developed with Pliant Therapeutics. Novartis terminated this partnership in 2022 as part of its pipeline prioritization efforts (Fiercebiotech.com)
Novartis’s Current Focus
Novartis has redirected its resources toward other therapeutic areas, including:
- Cardiovascular Diseases: The acquisition of Anthos Therapeutics for up to $3.1 billion to bolster its cardiovascular pipeline (WSJ.com)
- Oncology: The purchase of MorphoSys for $2.9 billion to expand its cancer treatment portfolio (Investopedia.com)
- Renal Diseases: The acquisition of Regulus Therapeutics for up to $1.7 billion, focusing on treatments for kidney diseases (prnewswire.com)
These moves suggest that Novartis concentrates on areas with a more straightforward path to market and a higher probability of success.
Would Novartis Reconsider Efimosfermin Today?
Given the current landscape, it’s unlikely that Novartis would pursue efimosfermin if it were available today. The company’s strategic focus has shifted away from MASH and divested its previous assets in this space. Moreover, Novartis’s recent acquisitions indicate a preference for areas with more established clinical pathways and market potential.
However, the success of efimosfermin in Phase II trials and GSK’s substantial investment underscore the evolving understanding of MASH and the potential for effective therapies. As the field advances, companies previously hesitant to invest in MASH may reevaluate their positions and begin to look at the many biotechs and academic groups working in the space.