Phase I, First-in-Human, Single and Multiple Ascending Dose- and Food-Effect Studies to Assess the Safety, Tolerability and Pharmacokinetics of a Novel Anti-hepatitis B Virus Drug, Bentysrepinine (Y101), in Healthy Chinese Subjects

Background and Objective Bentysrepinine (Y101), a derivative of repensine (a compound isolated from Dichondra repens Forst), is a novel phenylalanine dipeptide currently under development for the treatment of hepatitis B virus (HBV). The objectives of these studies were to assess the safety, tolerability and pharmacokinetics of bentysrepinine in healthy Chinese subjects. Methods Two randomised, double-blind, placebo-controlled trials evaluated a single oral dose (50-900 mg, study 01) and multiple doses (300 mg and 600 mg, study 02), and a randomised, open, crossover food-effect study (600 mg, study 03) of bentysrepinine was established. Safety and tolerability were assessed by adverse event (AE) reporting, clinical laboratory tests, physical examinations, vital sign monitoring and electrocardiogram (ECG). Plasma, urine and faecal samples were analysed using validated liquid chromatography tandem mass spectrometry (LC-MS/MS) methods to investigate the pharmacokinetics of bentysrepinine. Results Ninety-four subjects were enrolled, and bentysrepinine was well tolerated. Mild and reversible AEs occurred for single and multiple oral doses between 50 and 900 mg. The most common adverse effects were increased alanine aminotransferase (ALT) and aspartate transaminase (AST). Other clinically significant AEs included nausea and elevated urine leukocytes, urine red blood cells, transaminase, creatine kinase, total cholesterol, triglycerides, and low-density cholesterol. There were no clinically significant changes in the ECG, vital signs or laboratory assessments during the studies. The maximum tolerated dose (MTD) was not reached in the dose escalation study. Bentysrepinine was rapidly absorbed and metabolised with a mean time to reach maximum concentration (T-max) between 1-2 h and a mean terminal elimination half-life (t(1/2)) of approximately 1-3 h. In the single ascending dose study, the exposure including the area under the concentration-time curve (AUC) and the maximum plasma concentration (C-max) of bentysrepinine generally increased in a dose-dependent but not dose-proportional manner in the 50-900 mg dose range. The urinary excretion and faecal excretion of unchanged bentysrepinine were 2.98% and 4.58% of the total dose, respectively. In the multiple-dose study, no accumulation was found after repeated administration at the 300 mg and 600 mg dose levels. The food-effect study using a 600 mg single dose showed that food intake has an obvious effect on the absorption of bentysrepinine from tablets. No experimental differences were found based on sex. Conclusion Bentysrepinine exhibited acceptable safety and tolerability in healthy subjects in the dose range of 50-900 mg in both single- and multiple-dose studies. The drug did not exhibit linear pharmacokinetic characteristics. No accumulation was observed after the administration of multiple 300 and 600 mg doses. Bentysrepinine is extensively metabolised in the body. Food may increase its bioavailability.