Post-treatment HBsAg loss greater with TDF vs entecavir

In patients with chronic hepatitis B (CHB) without cirrhosis, the rates of hepatitis B surface antigen (HBsAg) loss appear to be higher after discontinuation of tenofovir disoproxil fumarate (TDF) than of entecavir, and this is particularly true for patients who have not experienced relapse after treatment discontinuation, according to a study.

For the study, researchers reviewed the medical records of 891 patients who had received entecavir (n=556) or TDF (n=335) and were followed up after treatment for at least 12 months (discontinued group). A cohort of 677 patients who had continued entecavir or TDF therapy for at least 4 years were also enrolled as the continued group.

Results showed that the rates of virological and clinical relapse, as well as retreatment, were much higher among patients who discontinued TDF than among those who discontinued entecavir in both the HBeAg-positive and HBeAg-negative subgroups.

In the discontinued group, the cumulative rates of HBsAg loss at 7 years were higher among patients who had been on TDF vs entecavir (35.4 percent vs 22.6 percent). This was consistent in the overall (p=0.019) and in propensity score-matched (p=0.015) analyses, especially among patients who achieved a sustained response (p<0.001).

On Cox regression analysis, factors that were independently associated with HBsAg loss in the discontinued group were TDF treatment, longer treatment duration, and lower HBsAg levels at end of treatment were independently associated with HBsAg loss.

Propensity-score matching analysis showed that in the entire cohort, HBsAg loss occurred with significantly higher frequency in the discontinued group than in the continued group (p<0.001), including HBeAg-positive and HBeAg-negative patients.