Genotypic Resistance Remains A Concern In Chronic Hepatitis B Patients With High Viral Load After Lamivudine And Adefovir Combination Therapy.

Aims: Previous studies have shown that baseline high viral load is closely related to treatment response in chronic hepatitis B (CHB). This study was designed to evaluate the differences of treatment responses between de novo lamivudine (LAM) plus adefovir (ADV) combination therapy compared with entecavir monotherapy (ETV).

Methods: A total of 185 HBeAg-positive CHB patients with high viral load were enrolled and assigned to the LAM+ADV group (n=90) or ETV group (n=95). Clinical variables are extracted from medical records.

Results: No significant differences in baseline variables were found between the two groups before antiviral treatment. After 104 weeks of antiviral therapy, the mean HBV DNA viral load in the LAM+ADV group decreased from 8.01±0.65 log copies/mL to 0.41±1.04 log copies/mL, compared with 8.04±0.57 log copies/mL to 0.57±1.28 log copies/mL in the ETV group (P=0.35). The virological response rate of LAM+ADV group was 82.2% (74/90) at 104 weeks of treatment, and 80.0% (76/95) in the ETV group (P=0.70). For HBeAg serological responses, HBeAg loss occurred in 23.3% (21/90) and 17.9% (17/95) in the LAM+ADV group and the ETV group, respectively (P=0.36). HBeAg seroconversion was observed in 15.6% (14/90) and 15.8% (15/95) in the LAM+ADV group and ETV group, respectively (P=0.96). However, after 104 weeks of treatment, genotypic resistance was confirmed in 8 cases in the LAM+ADV group, a proportion of 8.8% (8/90), compared with an absence of genotypic resistance in the ETV group (P=0.003).

Conclusion: Both de novo combination therapy of LAM+ADV and ETV monotherapy could effectively inhibit HBV replication in patients with high viral load. However, the rate of genotypic resistance in LAM+ADV treatment remains a concern. For CHB patients with high viral load, ETV treatment may be superior.