efimosfermin

Efimosfermin is a long-acting, once-monthly fibroblast growth factor 21 (FGF21) analogue designed as a recombinant fusion protein based on human IgG and FGF21. It is engineered to provide an extended systemic half-life of approximately 21 days and is produced in mammalian cells to optimize glycosylation quality[2][3]. Efimosfermin acts as an agonist at FGF21 receptors, modulating metabolic pathways involved in liver fat metabolism, inflammation, and fibrosis. The drug has demonstrated significant efficacy in reducing liver steatosis, improving markers of liver injury and fibrosis, and resolving metabolic dysfunction-associated steatohepatitis (MASH), previously known as non-alcoholic steatohepatitis (NASH)[3][5][8]. Clinical trials have shown that monthly subcutaneous administration leads to statistically significant improvements in both fibrosis regression and MASH resolution without worsening of either condition[3][5]. Efimosfermin also improves cardiometabolic parameters such as glycemic control and triglyceride levels[6][7]. The most common adverse events are mild-to-moderate gastrointestinal symptoms. Originally developed by Boston Pharmaceuticals (formerly BOS-580), the program was acquired by GSK for further development with anticipated first launch around 2029[6][8].

Other names

efimosfermin-alfaefimosfermin alfa