Stopping nucleot(s)ide analogues in non-cirrhotic HBeAg-negative chronic hepatitis B patients: HBsAg loss at 96 weeks is associated with low baseline HBsAg levels

Background and Aims: Current guidelines recommend long-term nucleot(s)ide analogue (NA) therapy for patients with HBeAg-negative chronic hepatitis B (CHB). However, disease remission has been described after stopping NA therapy, as well as HBsAg loss. Methods: We performed a prospective multi-centre cohort study of stopping NA therapy. Inclusion criteria were HBeAg-negative CHB, the absence of cirrhosis and HBVDNA<lower limit of quantification for ≥18 months. We assessed virological and biochemical outcomes including HBsAg loss, as well as NA restart rates, over 96 weeks. Results: In total, 110 patients [62% entecavir (ETV); 28% tenofovir (TDF), 10% other] were enrolled. Median age was 56 years, 57% were male, 85% were Asian, median baseline HBsAg level was 705 (214–2325) IU/ml. Virological reactivation occurred in 109/110 patients, median time to detection was 8 (4–12) weeks, and occurred earlier after stopping TDF versus ETV (median 4 vs. 12 weeks p < 0.001). At week 96, 77 (70%) remained off-treatment, 65 (59%) had ALT <2× ULN, 31 (28%) patients were in disease remission with HBVDNA <2000 IU/ml plus ALT <2× ULN and 7 (6%) patients had lost HBsAg. Baseline HBsAg ≤10 IU/ml was associated with HBsAg loss (6/9 vs. 1/101 p < 0.001). ALT >5× ULN occurred in 35 (32%); ALT flares were not associated with HBsAg loss. There were no unexpected safety issues. Conclusion: Virological reactivation was very common after stopping NA therapy and occurred earlier after stopping TDF versus ETV. The majority of patients had ALT <2× ULN at week 96, but only one-third achieved disease remission and HBsAg loss was rare. Very low HBsAg levels at baseline were uncommon but predicted for HBsAg loss and disease remission.