GS-0976 (Firsocostat): an investigational liver-directed acetyl-CoA carboxylase (ACC) inhibitor for the treatment of non-alcoholic steatohepatitis (NASH).

Introduction: De novo lipogenesis (DNL) plays a major role in fatty acid metabolism and contributes significantly to triglyceride accumulation within the hepatocytes in patients with nonalcoholic steatohepatitis (NASH). Acetyl-CoA carboxylase (ACC) converts acetyl-CoA to malonyl CoA and is a rate-controlling step in DNL. Furthermore, malonyl-CoA is an important regulator of hepatic mitochondrial fat oxidation through its ability to inhibit carnitine palmitoyltransferase I. Therefore, inhibiting ACC pharmacologically represents an attractive approach to treating NASH.Areas covered: This article summarizes preclinical and clinical data on the efficacy and safety of the liver-targeted ACC inhibitor GS-0976 (Firsocostat) for the treatment of NASH. In a phase 2 trial that included 126 patients with NASH and fibrosis, GS-0976 20 mg daily for 12 weeks showed significant relative reduction in liver fat by 29%; however, treatment was associated with an increase in plasma triglycerides with 16 patients having levels >500 mg/dL.Expert opinion: Preclinical and preliminary clinical data support the development of GS-0976 as treatment for NASH. ACC-induced hypertriglyceridemia can be mitigated by fish oil or fibrates, but the long-term cardiovascular effects require further investigations.