Relapse of hepatitis B in HBeAg-negative chronic hepatitis B patients who discontinued successful entecavir treatment: The case for continuous antiviral therapy

Background/Aims: To evaluate the off-treatment durability of response in HBeAg-negative chronic hepatitis B patients who achieved a protocol-defined 'Response' (HBV-DNA < 0.7 MEq/mL and ALT < 1.25 × ULN) with entecavir at 48 weeks and the efficacy of entecavir in patients treated beyond one year. Methods: Entecavir-treated and lamivudine-treated patients who achieved a protocol-defined 'Response' were evaluated off-treatment for HBV-DNA < 300 copies/mL and ALT normalisation. Entecavir- and lamivudine-treated patients who achieved a protocol-defined 'Virological Response' (HBV-DNA < 0.7 MEq/mL but ALT ≥ 1.25 × ULN) at 48 weeks, continued blinded treatment until they achieved Response or 96 weeks, whichever came first. Results: Among 'Responders' who discontinued treatment after 48 weeks, 7/257 (3%) entecavir-treated and 10/201 (5%) lamivudine-treated patients sustained HBV-DNA below 300 copies/mL at 24-weeks off-treatment. Among the 54 patients who continued blinded treatment in the second year, 7/26 (27%) entecavir-treated and 6/28 (21%) lamivudine-treated patients normalised ALT and 22/26 (85%) entecavir-treated and 16/28 (57%) lamivudine-treated patients maintained HBV-DNA < 300 copies/mL at end-of-dosing. The safety profiles of both drugs remained comparable through a second year of treatment. Conclusions: The majority of protocol-defined Responders relapsed after 1 year when treatment was discontinued. Treatment with entecavir beyond 1 year provided continued virological and biochemical benefit.