Switching from tenofovir disoproxil fumarate to tenofovir alafenamide in virologically suppressed patient with chronic hepatitis B

Background and Aim: Our study evaluated the outcomes of switching from tenofovir disoproxil fumarate (TDF) to tenofovir alafenamide (TAF) in patients with chronic hepatitis B (CHB). We assessed viral and biochemical responses as well as changes in the estimated glomerular filtration rate (eGFR) and bone mineral density (BMD). Methods: This retrospective multicenter study included CHB patients who achieved virologic response (VR) (HBV DNA < 20 IU/mL) while on TDF and were subsequently switched to TAF between April 2018 and October 2021. Results: This study included 309 patients with a median age of 59 years, and 42.1% were male. The mean duration of TDF and TAF administration were 54.0 and 37.5 months, respectively. All patients maintained VR after switching to TAF. Alanine aminotransferase (ALT) normalization rate significantly increased 6 months after switching (74.8%–83.5%; P = 0.008). Adjusted eGFR significantly improved at 6 months (+5.55 ± 10.52 mL/min/1.73 m²; P < 0.001) and 12 months (+6.02 ± 10.70 mL/min/1.73 m²; P < 0.001) after switching. In the subgroup of patients with renal impairment (eGFR < 60 mL/min/1.73 m²), significant improvement in renal function was observed at 6 months (+0.6 ± 10.5 mL/min/1.73 m²; P < 0.001) and 12 months (+1.0 ± 10.7 mL/min/1.73 m²; P < 0.001) after switching to TAF. In patients with osteoporosis (n = 182), switching to TAF resulted in significant improvement in spine and hip BMD at 12 months, with increases of 9.7% (95% CI: 7.0–12.5) and 9.4% (95% CI: 7.0–11.8), respectively. Conclusion: In this real-world study, switching to TAF was effective and safe in patients, with notable improvements in ALT levels, renal function, and BMD.