Safety, pharmacokinetics, and antiviral effects of ABI-H0731, a hepatitis B virus core inhibitor: a randomised, placebo-controlled phase 1 trial.

Background: Therapies with novel mechanisms of action against hepatitis B virus (HBV) infection are being explored with the goal of achieving a functional cure (sustained off-treatment response) without requiring lifelong therapy. We aimed to evaluate the pharmacokinetics, safety, and antiviral activity of ABI-H0731, an investigational inhibitor of the HBV core protein. Method(s): This phase 1, randomised, placebo-controlled study was done in two parts. In part 1, healthy adults without hepatitis B aged 18-65 years at one clinical research centre in New Zealand (eight participants per dose cohort) were randomly assigned (3:1) to receive single oral doses of ABI-H0731 (100, 300, 600, or 1000 mg) or matching placebo, or once-daily or twice-daily doses of ABI-H0731 800 mg or matching placebo for 7 days. In part 2, adults aged 18-65 years at clinical research centres in New Zealand, Australia, the UK, Hong Kong, Taiwan, and South Korea with chronic HBV (12 participants per dose cohort) were randomly assigned (5:1) to receive ABI-H0731 (100, 200, 300, or 400 mg) or matching placebo once daily for 28 days. In part 2, participants were required to have HBeAg-positive or HBeAg-negative chronic HBV infection, with serum HBV DNA concentrations of at least 2 x 104 IU/mL (HBeAg-positive) or 2 x 103 IU/mL (HBeAg-negative) and serum alanine aminotransferase concentrations less than seven times the upper limit of normal. Both parts used simple randomisation, with study participants, site personnel, and study monitors masked to treatment assignments. The primary study objective was dose-related safety and tolerability of ABI-H0731 in healthy volunteers and in participants with chronic HBV infection, assessed in all treated participants. Key secondary assessments included pharmacokinetic analyses and virological responses. This study is registered with ClinicalTrials.gov, identifier NCT02908191 and is completed. Finding(s): 48 [61%] of 79 healthy volunteers were enrolled in the sing