Non-invasive evaluation of response to obeticholic acid in patients with NASH: Results from the REGENERATE study.

BACKGROUND & AIMS

Nonalcoholic steatohepatitis (NASH) is a chronic, progressive fibrotic liver disease that can lead to cirrhosis. While liver biopsy is considered the reference standard for histologic diagnosis of NASH and staging of fibrosis, use in clinical practice is limited. Noninvasive tests (NITs) are increasingly being used to identify and stage liver fibrosis in patients with NASH, and several can assess liver-related outcomes. We report changes in various NITs in patients treated with obeticholic acid (OCA) or placebo in the phase 3 REGENERATE study.

METHODS

Patients with NASH and fibrosis stage F2 or F3 (N = 931) were randomized (1:1:1) to receive placebo, OCA 10 mg, or OCA 25 mg once daily. Various NITs based on clinical chemistry and/or imaging were evaluated at baseline and throughout the study.

RESULTS

Rapid, sustained reductions from baseline in alanine aminotransferase (ALT), aspartate aminotransferase (AST), and gamma-glutamyl transferase (GGT) levels, as well as in FIB-4, FibroTest, FibroMeter, and FibroScan-AST scores were observed in OCA-treated patients versus placebo. Reduction in liver stiffness by vibration-controlled transient elastography (VCTE) was observed in the OCA 25 mg group versus placebo group at Month 18. NIT changes were associated with shifts in histologic fibrosis stage. The greatest improvements were observed in patients with ≥1-stage fibrosis improvement; however, improvements in ALT, AST, FIB-4, and FibroTest were also observed in OCA-treated patients whose histologic fibrosis remained stable.

CONCLUSIONS

Based on the REGENERATE Month 18 interim analysis, rapid and sustained improvements in various NITs were observed with OCA treatment. Dynamic changes in selected NITs separated histologic responders from non-responders. These results suggest that NITs may be useful in assessing histologic response to OCA therapy.

LAY SUMMARY

Nonalcoholic steatohepatitis (NASH) is a chronic, progressive liver disease that can lead to cirrhosis. To diagnose and assess liver fibrosis (scarring) in patients with NASH, noninvasive tests (NITs) are increasingly being used rather than liver biopsy, which is invasive, expensive, and can be risky. In the REGENERATE study evaluating the effects of obeticholic acid versus placebo in patients with NASH, various NITs were evaluated as well. This analysis shows that improvements in levels of certain blood components, as well as favorable results of ultrasound imaging and proprietary tests of liver function, were associated with improvements in liver fibrosis after treatment with obeticholic acid, suggesting that NITs may be useful alternatives to liver biopsy in assessing NASH patients' response to therapy.