Switching from entecavir to tenofovir alafenamide for maintaining complete virological response in chronic hepatitis B.

Background And Aim: Hepatocellular carcinoma development can be decreased by achieving and maintaining complete virological response (CVR) in chronic hepatitis B. However, it is unclear whether switching from entecavir (ETV) to tenofovir alafenamide (TAF) could achieve and maintain CVR in patients with low-level viremia (LLV; HBV DNA ≤ 3.3 log IU/mL) or occasional detectable HBV DNA during ETV treatment. Therefore, we aimed to examine whether the switching from ETV to TAF is effective in achieving CVR in patients with LLV or occasional detectable HBV DNA.

Methods: This study comprised 45 patients who switched from ETV to TAF. All patients received ETV and TAF for >2 years, and the HBV DNA levels were measured every 3 months. Maintaining undetectable HBV DNA during 2-year period is defined as CVR. The primary endpoint is the CVR rate during ETV and TAF treatment.

Results: The CVR rate for each of the 2 years of ETV and TAF therapy was 33.3% (15/45) and 68.9% (31/45,  < 0.01), respectively, and the CVR rate increased by switching from ETV to TAF. In patients with occasional detectable HBV DNA during ETV treatment (22 patients), 15 achieved CVR and 7 maintained occasional detectable HBV DNA. In patients with LLV during ETV treatment (eight patients), three achieved CVR and five had occasional detectable HBV DNA.

Conclusion: Switching from ETV to TAF increases the CVR rate in patients with LLV or occasional detectable HBV DNA and could be an alternative treatment option.