Efficacy and safety of switching from entecavir to tenofovir alafenamide in chronic hepatitis B patients with low-level viremia: a real-world 48-week extension study

ABSTRACT Chronic hepatitis B (CHB) patients receiving entecavir (ETV) treatment might develop low-level viremia (LLV), which is proven to be associated with worse clinical outcomes, such as risk of drug-related mutations, progression to cirrhosis, and even hepatocellular carcinoma. This real-world prospective study evaluated the efficacy and safety of switching from ETV to tenofovir alafenamide fumarate (TAF) in CHB patients with LLV. From August 2020 to August 2023, 351 ETV-experienced CHB patients with LLV were enrolled from eight hospitals. Patients either continued ETV or switched to TAF. The primary efficacy endpoint was the complete virological response (CVR) at week 48; the safety endpoint was the first occurrence of any clinical adverse event during the treatment; and the renal safety and change in blood lipids were also assessed. Inverse probability treatment weighting (IPTW) generated 350.9 cases in the ETV group and 351.4 cases in the TAF group. After the 48-week treatment, the CVR and ALT normalization rates in the TAF group were 75.3% and 67.8%, which were significantly higher than 11.4% and 17.1% in the ETV group ( P < 0.001). The two strategies showed comparable impact on renal function and lipid profiles, regarding low-density lipoprotein (LDL) cholesterol and the total cholesterol to high-density lipoprotein (TC/HDL) ratio. Therefore, for ETV-treated patients with LLV, switching to TAF is superior compared with continuing ETV treatment in terms of virological and biochemical response, with non-inferior renal safety and lipid profiles. CLINICAL TRIALS This study is registered with the Chinese Clinial Trial Registry as ChiCTR2400089257 .