Optimized strategy of switching to tenofovir alafenamide fumarate treatment for nucleos(t)ide analogue experienced patients with chronic hepatitis B.

Background: This study aimed to evaluate the efficacy and safety of tenofovir alafenamide fumarate (TAF) in nucleos(t)ide analogue (NA)-experienced patients with chronic hepatitis B (CHB) who exhibited partial virological response (PRT) or low-level viremia (LLV). Methods: This single-center, retrospective, real-world study enrolled NA-experienced CHB patients who were switched to TAF treatment. Patients were categorized into the PRT (HBV DNA > 2,000 IU/mL) or LLV (20 IU/ mL < HBV DNA ≤ 2,000 IU/mL) groups according to baseline HBV DNA levels. The dynamic changes in HBV DNA, HBsAg, HBeAg, ALT, and APRI were analyzed after switching to TAF. Results: A total of 91 CHB patients with prior NA treatment and detectable HBV DNA after at least 48 weeks of therapy were enrolled and subsequently switched to TAF. Among them, 24 patients had PRT, and 67 patients had LLV. The complete virological response rate (HBV DNA < 20 IU/mL) in the PRT group was 29.1% at week 24 and 75.0% at week 48; in the LLV group, it was 76.1% and 88.1%, respectively. Both groups showed a decline in HBeAg levels from baseline to week 24 and 48. In the PRT group, HBsAg levels decreased by 9.0% and 5.0% at week 24 and 48, respectively; in the LLV group, the reductions were 2.1% and 3.6%. The ALT normalization rate increased by 24.2% at week 48 compared with baseline. Additionally, eGFR levels improved after switching to TAF. No serious adverse events (SAEs) or deaths related to adverse events were observed. Conclusion: This real-world study suggests that switching to TAF is an effective and well-tolerated therapeutic strategy for NA-experienced CHB patients with PRT or LLV, offering a promising approach for treatment optimization.