Body weight changes in treated hepatitis B patients switching to tenofovir alafenamide^☆

Switching to a tenofovir alafenamide (TAF)-containing regimen has been reported to be associated with body weight gain in human immunodeficiency virus-infected subjects. We aimed to investigate the body weight change and virological, hepatic, and renal outcomes of TAF switching among chronic hepatitis B (CHB) patients.

This retrospective study included 121 CHB patients who were switched to TAF after >12 months of treatment with another nucleot(s)ide analog (NUC). All patients were monitored for 12 months.

The cohort was mostly Asian (96.7%) with a mean age of 55 years, 72% male, 14% cirrhosis, 21% HBeAg positive, and 75% with prior use of tenofovir disoproxil fumarate. At 12 months after TAF switching, their body weight significantly increased from 66.4 ± 11.8 to 67.8 ± 12.3 kg (p < 0.001), and 21.1% of the subjects had a ≥5% weight gain. Patients without diabetes or hypertension were more likely to have a body weight gain. Meanwhile, the complete viral suppression rate increased significantly from 89.3% to 96.2% (p = 0.016). The rate of alanine aminotransferase normalization also increased significantly from 71.1% to 87.6% (p < 0.001) by local criteria and from 58.7% to 70.2% (p = 0.029) by AASLD criteria. The mean eGFR (mL/min/1.73 m²) did not change (88.2 ± 18.8 vs. 87.2 ± 17.5, p = 0.28). However, for the subgroup with GFR <90 at TAF switching, there was a significant improvement in eGFR (72.9 ± 12.0 vs. 75.7 ± 14.2, p = 0.027).

In real-world NUC-experienced CHB patients, unexpected body weight gain was observed after TAF switching. The mechanism needs to be investigated in the future.