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The objectives of this phase I study are to assess the safety, tolerability, and pharmacokinetics (PKs) of RO7049389 in healthy Chinese volunteers (HVs) and evaluate potential ethnic differences in the safety and PKs using data from this study and the first‐in‐human study (in which most of the HVs were non‐Asian). HVs randomly received a single dose of 200–600 mg of RO7049389 or a placebo in a single ascending dose (n = 28) or multiple doses of 200–400 mg of RO7049389 or a placebo in multiple ascending doses (n = 24). Safety and tolerability were monitored throughout the study. Serial blood samples were collected for PK analysis. RO7049389 was safe and well‐tolerated in the HVs. The time to maximum concentration ranged from 1.5 to 3.0 h, and terminal half‐life ranged from 3.66 to 14.6 h. A single dose of 200–600 mg and multiple doses of 200–400 mg exhibited nonlinear PKs. In general, the safety profiles were comparable between non‐Asian and Asian HVs, but the plasma exposure of RO7049389 in Chinese HVs was higher than that in non‐Asian HVs. The data generated from this study will provide guidance for future clinical studies on RO7049389 in Chinese/Asian patients with hepatitis B virus.

RO7049389, an inhibitor of hepatitis B virus (HBV) capsid assembly, is being developed for the treatment of patients with chronic HBV infection. The objectives of this first-in-human study are to assess the safety, tolerability, pharmacokinetics (PK), food effect, inhibitory effect on CYP3A, and effect on QT of RO7049389 in healthy participants. Five components, single-ascending-dose (SAD) cohorts, multiple-ascending-dose (MAD) cohorts, food effect assessment, drug-drug interaction assessment, and concentration-QT analysis were integrated in one study (five-in-one). Participants randomly received a single dose of 150 to 2,500 mg RO7049389 or placebo in SAD cohorts (n = 41), or multiple doses of 200 to 800 mg RO7049389 or placebo in MAD cohorts (n = 42). A single doses of 450 mg RO7049389 was administered under fasted and fed condition. The microdose of midazolam was administered before and after multiple dosing of RO7049389. Safety and tolerability were monitored throughout the study. Serial blood and urine samples were collected for the PK analysis. RO7049389 was safe and well tolerated in healthy participants. Absorption and elimination of RO7049389 occurred rapidly in plasma with minimal recovery in urine. Greater than dose-proportional increases in plasma exposure were observed. Exposure of RO7049389 (450 mg) increased by ∼2-fold when administered with a high-fat meal. The inhibition effect of RO7049389 on CYP3A was weak (

Materials and methods A full length HBV genome was cloned and sequenced from serum of a chronic hepatitis B (CHB) patient. The genome and sterilized Milli-Q water were transfected to HepG2 and HepG2.2.15 cells, respectively, by lipofectamine 2000. The prior cell line was named HepG29BL. The two cell lines were collected post transfection 48 hours. Differential genes were examined using Affy Human U133 2.0A gene chip; Real time polymerase chain (RT-PCR) was performed to confirm the expression of lumican in six human hepatoma carcinoma cell lines.

The reasons for adefovir dipivoxil (ADV) treatment failures appear diverse. Few studies have reported full-length hepatitis B virus (HBV) genome in patients with ADV treatment failures. The patients were from a phase III clinical trial that investigated the antiviral response to ADV in China. Seven patients had increase in HBV-DNA (1 log(10) copies/ml above on-treatment nadir) at week 52. The serum HBV-DNA levels were above 10(4)copies/ml at week 92 in four of them. Sixteen full-length HBV genomes from the four patients at four time points were sequenced using cloning sequencing method. The frequency of substitutions at week 52 was higher than at weeks 28(16 wt) and 92(80). HBV-DNA reduction was correlated negatively with the frequency of substitutions at the three time points. No published ADV-resistant mutations were detected. The mutations, including substitutions in immunogenic epitopes and conserved sites of the polymerase gene, were frequent during ADV treatment. Amino acid deletions in X gene and basal core promoter/pre-core mutations appeared before or during ADV treatment. The substitutions in immunogenic epitopes (mainly of the surface gene) and conserved sites of the polymerase gene other than ADV-resistant mutations may have influenced antiviral efficacy in the study. More potent antiviral drugs may be important to rescue individual patients and for public health safety. It is needed to study how these substitutions influence HBV replication, disease progression, and antiviral treatment efficacy.