Efruxifermin
Efruxifermin (EFX, AKR-001)
Also known as: EFX, AKR-001
A weekly FGF21 analog that reversed cirrhosis in a subset of MASH patients at 96 weeks in Phase 2b, with three Phase 3 SYNCHRONY trials under way.
Overview
Efruxifermin fuses FGF21 to an antibody Fc domain to extend its half-life. FGF21 is a liver-derived hormone that improves insulin sensitivity and lipid handling. In the SYMMETRY Phase 2b, 96 weeks of treatment produced reversal of compensated cirrhosis in some F4 patients, the first drug to show that. Akero's Phase 3 program (SYNCHRONY Histology, Real-World and Outcomes) is enrolling, with the histology readout guided to 2027.
Mechanism of action
Long-acting FGF21 receptor agonism (FGFR1c/beta-klotho) that lowers liver fat, improves insulin sensitivity and reduces fibrosis.
Key studies & citations
- Human2026
SYNCHRONY Phase 3 program of efruxifermin
Three pivotal trials across fibrosis stages.
Akero Therapeutics - Human2025
Efruxifermin in compensated cirrhosis due to MASH (SYMMETRY, 96 weeks)
Cirrhosis reversal in a subset of F4 patients.
Akero press release / NEJM
Frequently asked questions
What is FGF21?
Fibroblast growth factor 21 is a hormone made mainly by the liver during fasting that improves how the body handles fat and sugar. Analogs like efruxifermin mimic it with a longer duration.
Does efruxifermin cause weight loss?
Modest at most. Its main effects are on liver fat, fibrosis and lipids rather than appetite.