By Fineline Cube 
UK-based pharmaceutical giant GlaxoSmithKline (GSK, NYSE: GSK) has entered into an agreement to acquire BP Asset IX, Inc., a subsidiary of US-based Boston Pharmaceuticals, a portfolio company of B-Flexion. The acquisition grants GSK access to efimosfermin alfa, a phase III-ready specialty medicine for treating and preventing the progression of steatotic liver disease (SLD).
Deal Structure
Under the terms of the agreement, GSK will pay an upfront fee of USD 1.2 billion. Additionally, Boston Pharmaceuticals is eligible to receive up to USD 800 million in success-based milestone payments. GSK will also be responsible for milestone payments and tiered royalties to Novartis Pharma AG for efimosfermin.
Drug Overview
Efimosfermin alfa is a novel, once-monthly fibroblast growth factor 21 (FGF21) analog designed to address key metabolic pathways. It aims to reduce liver fat accumulation, alleviate liver inflammation, and reverse liver fibrosis in patients with metabolic dysfunction-associated steatohepatitis (MASH). The drug is currently in clinical trials for moderate to severe fibrosis, including cirrhosis, and is not yet approved for prescription.
Strategic Rationale
Efimosfermin’s direct antifibrotic mechanism and GSK’s expertise in human genetics and disease phenotyping position the drug to address advanced stages of SLD. GSK also sees potential in combining efimosfermin with its siRNA therapeutic GSK’990, currently in development for other SLD patient subsets.-Fineline Info & Tech