Abstract: Objective The aim of this study was to investigate clinical efficacy of tenofovir amibufenamide (TMF) and tenofovir alafenamide fumarate (TAF) in rescue treatment of entecavir (ETV)-treated patients with chronic hepatitis B(CHB) and low-level viremia (LLV). Methods 68 patients with CHB were enrolled in our hospital between January 2022 and January 2024, the enrolled patients were all ETV-treated for at least 12 months, showing poor virological response with LLV and were randomly assigned to receive TMF or TAF for 48 weeks. Liver stiffness measurement (LSM) was evaluated by ultrasonic liver transient elastography, serum HBV markers, biochemical parameters and HBV DNA loads were routinely detected. Serum laminin(LN),collagen type Ⅳ(Ⅳ-C), precollagen-Ⅲ (PC-Ⅲ)and hyaluronic acid(HA)levels were assayed by ELISA. Results By end of 48 week treatment, LSM as well as serum HA, LN, Ⅳ-C and PCⅢ levels in TMF-treated patients were (6.8±1.2)KPa, (171.2±25.9)ng/mL, (147.5±42.3)ng/mL, (174.3±46.3)ng/mL and (56.8±12.4)ng/mL, all not significantly different as compared to [(6.9±1.2)KPa, (175.2±34.6)ng/mL, (148.2±46.3)ng/mL, (175.4±42.1)ng/mL and (55.5±19.5)ng/mL, respectively] in TAF-treated patients (P>0.05); serum bilirubin, ALT and AST levels in TMF-treated patients were (16.4±1.4)μmol/L, (40.3±4.8)U/L and (32.4±5.1)U/L, all not significantly different as compared to [(17.3±1.2)μmol/L, (41.8±4.5)U/L and (36.9±4.9)U/L, respectively] in TAF-treated patients (P>0.05); virological and biochemical response rates in the two groups were not significantly different as serum HBV DNA transferred to negative and serum ALT level returned to normal(P>0.05) in all patients. Conclusion As for patients with CHB and poor response to ETV treatment, rescue antiviral therapy with TMF or TAF is both satisfactory, with complete virological response, and the long-term efficacy should be followed-up in the future.

Key words: Hepatitis B, Entecavir, Low-level viremia, Tenofovir amibufenamide, Tenofovir alafenamide fumarate, Rescue therapy