Oral Insulin Alleviates Liver Fibrosis and Reduces Liver Steatosis in Patients With Metabolic Dysfunction-associated Steatohepatitis and Type 2 Diabetes: Results of Phase II Randomized, Placebo-controlled Feasibility Clinical Trial

Background and Aims: Metabolic dysfunction-associated steatohepatitis is an advanced form of nonalcoholic fatty liver disease and a leading cause of end-stage liver disease and transplantation. Insulin resistance and inflammation underlie the pathogenesis of the disease. Methods: This double-blind, randomized, placebo-controlled, multicenter feasibility clinical trial aimed to determine the safety of oral 8 mg insulin in patients with metabolic dysfunction-associated steatohepatitis and type 2 diabetes mellitus. Patients were treated twice daily for 12 weeks with an 8 mg insulin (n = 21) or placebo (n = 11) capsule. Safety was monitored throughout the study. MRI-proton density fat fraction assessed liver fat content, and Fibroscan® measured liver fibrosis and steatosis levels at screening and after 12 weeks of treatment. Results: No severe drug-related adverse events were reported during the study. After 12 weeks of treatment, mean percent reductions in whole-liver (−11.2% vs −6.5%, respectively) and liver segment 3 (−11.7% vs +0.1%, respectively) fat content was higher in the insulin than in the placebo arm. Patients receiving insulin showed a median −1.2 kPa and −21.0 dB/m reduction from baseline fibrosis and steatosis levels, respectively, while placebo-treated patients showed median increases of 0.3 kPa and 13.0 dB/m, respectively. At Week 12, oral insulin was associated with a mean of 0.27% reduction and placebo with a 0.23% increase from baseline hemoglobin A1c levels. Mean percent changes from baseline alanine aminotransferase, and aspartate aminotransferase levels were −10% and −0.8%, respectively, in the oral insulin and 3.0% and 13.4%, in the placebo arm. Conclusion: The results of this feasibility study support the safety and potential therapeutic effect of orally delivered insulin on liver fibrosis, fat accumulation, and inflammatory processes (NIH Clinical Trials No. NCT04618744).