The Food and Drug Administration (FDA) has granted Fast Track designation to efruxifermin for the treatment of nonalcoholic steatohepatitis (NASH).

Efruxifermin is a differentiated Fc-FGF21 fusion protein designed to mimic the biological activity of fibroblast growth factor 21 (FGF21), which regulates multiple metabolic pathways and cellular processes. The Company believes that efruxifermin may potentially treat NASH by delivering sustained and balanced signaling through FGF21 receptors in liver and adipose tissue. 

The designation was supported by data from the randomized, double-blind, placebo-controlled phase 2a BALANCED study ( Identifier: NCT03976401), which evaluated the efficacy and safety of efruxifermin in 80 biopsy-confirmed NASH patients. Findings showed that treatment with efruxifermin resulted in statistically significant reductions in hepatic fat, which were associated with decreases in markers of liver injury and fibrosis. 

“The FDA Fast Track designation for [efruxifermin] is an important step forward in potentially bringing [efruxifermin] to the growing number of patients impacted by NASH,” said Andrew Cheng, MD, PhD, president and chief executive officer of Akero. “Backed by positive clinical data, including a 2-stage improvement in fibrosis for 50% of all treated patients with F2 or F3 fibrosis at baseline, we believe [efruxifermin] has the potential to be among the first investigational therapies approved for treatment of both advanced fibrotic (F2/F3) and cirrhotic (F4) NASH.”

The Company is currently investigating efruxifermin in noncirrhotic patients with NASH in the phase 2 HARMONY study ( Identifier: NCT04767529) and in patients with compensated cirrhosis due to NASH in the phase 2 SYMMETRY study ( Identifier: NCT05039450).


  1. Akero Therapeutics receives FDA Fast Track designation for efruxifermin (EFX) for the treatment of NASH. News release. Akero Therapeutics, Inc. October 19, 2021. Accessed October 20, 2021.
  2. Harrison SA, Ruane PJ, Freilich BL, et al. Efruxifermin in non-alcoholic steatohepatitis: a randomized, double-blind, placebo-controlled, phase 2a trial. Nat Med 27, 1262-1271 (2021). doi: 10.1038/s41591-021-01425-3