Efficacy and Safety of Switching from Entecavir to Tenofovir Alafenamide in Chronic Hepatitis B: A Multicenter Randomized Trial in Korea

Background/Aims: Tenofovir alafenamide (TAF) has emerged as a safe and effective alternative to entecavir (ETV) in the management of chronic hepatitis B (CHB). We aimed to evaluate the efficacy and safety of switching to TAF compared with maintaining ETV in patients with CHB who had achieved virologic suppression on ETV. Methods: In this multicenter, randomized, open-label, active-controlled, noninferiority clinical trial conducted at 13 Korean centers, 196 CHB patients who had experienced virologic suppression after ≥24 weeks of ETV therapy were randomized 1:1 to switch to TAF (n=95) or continue on ETV (n=101). The primary endpoint was the proportion of patients with hepatitis B virus (HBV) DNA <29 IU/mL at week 48 (per-protocol set). Secondary endpoints included alanine aminotransferase (ALT) normalization, hepatitis B surface antigen and hepatitis B e antigen serologic responses, and safety outcomes. Results: Among 188 patients in the per-protocol set (89 TAF, 99 ETV), the HBV suppression rate at week 48 was 100.0% in the TAF group and 99.0% in the ETV group (difference, 1.03%; one-sided 97.5% confidence interval, -0.96 to infinity). ALT normalization rates at week 48 were comparable between groups (55.0% in TAF vs 38.7% in ETV; p=0.26; American Association for the Study of Liver Diseases criteria). Hepatitis B e antigen seroconversion rates were also similar at week 48 (0.0% vs 12.5%; p=0.21). Safety profiles, including renal function, did not significantly differ between the two groups. Conclusions: Switching from ETV to TAF was noninferior to continuing ETV in maintaining virologic suppression, with comparable biochemical, serologic, and safety outcomes. (ClinicalTrials. gov identifier NCT06000657).