HBV relapse rates in patients who discontinue tenofovir disoproxil fumarate with or without switching to tenofovir alafenamide

Background/Aims: The incidence and relapse pattern in patients stopping tenofovir alafenamide (TAF), a prodrug of tenofovir which is more concentrated in hepatocytes, is unknown. Methods: HBeAg-negative CHB patients stopping tenofovir disoproxil fumarate (TDF) (off-TDF) or who had switched to TAF more than 3 months before discontinuation (off-TAF) were recruited. The propensity score-matching method (PSM) was used, creating a ratio of 1:3 between the off-TAF versus the off-TDF groups to adjust for associated factors. Results: After PSM, 180 off-TDF and 60 off-TAF patients were analyzed. The cumulative rates of virological and clinical relapse at 52 weeks were 75.1% and 58.5% respectively in the off-TDF group and 91.1% and 61.6% in the off-TAF group. Patients in the off-TAF group had significantly higher rates of virological relapse than those in the off-TDF group (p = 0.021), but not clinical relapse (p = 0.785). Multivariate cox regression analysis showed that off-TAF group was an independent factor for virological relapse, but not clinical relapse. Severity of clinical relapse and hepatic decompensation rate were comparable between off-TDF and off-TAF groups Conclusions: The off-TAF group had a higher virological relapse rate than the off-TDF group. The difference in clinical relapse pattern and severity was not clinically important between the two groups.