Adding Pegylated Interferon to Entecavir for Hepatitis B e Antigen-Positive Chronic Hepatitis B: A Multicenter Randomized Trial (ARES Study)

Entecavir (ETV) is a potent inhibitor of hepatitis B viral replication, but long-term therapy may be required. We investigated whether adding on pegylated interferon (Peg-IFN) to ETV therapy enhances serological response rates. In this global investigator-initiated, open-label, multicenter, randomized trial, hepatitis B e antigen (HBeAg)-positive chronic hepatitis B (CHB) patients with compensated liver disease started on ETV monotherapy (0.5 mg/day) and were randomized in a 1:1 ratio to either Peg-IFN add-on therapy (180 mu g/week) from week 24 to 48 (n=85) or to continue ETV monotherapy (n=90). Response was defined as HBeAg loss with HBV DNA <200 IU/mL at week 48. Responders discontinued ETV at week 72. All patients were followed until week 96. Response was achieved in 16 of 85 (19%) patients allocated to the add-on arm versus 9 of 90 (10%) in the monotherapy arm (P=0.095). Adjusted for HBV DNA levels before randomized therapy, Peg-IFN add-on was significantly associated with response (odds ratio: 4.8; 95% confidence interval: 1.6-14.0; P=0.004). Eleven (13%) of the add-on-treated patients achieved disease remission after ETV cessation versus 2 of 90 (2%) of those treated with monotherapy (P=0.007), which was 79% (11 of 14) versus 25% (2 of 8) of those who discontinued ETV (P=0.014). At week 96, 22 (26%) patients assigned add-on versus 12 (13%) assigned monotherapy achieved HBeAg seroconversion (P=0.036). Peg-IFN add-on led to significantly more decline in hepatitis B surface antigen, HBeAg, and HBV DNA (all P<0.001). Combination therapy was well tolerated. Conclusion: Although the primary endpoint was not reached, 24 weeks of Peg-IFN add-on therapy led to a higher proportion of HBeAg response, compared to ETV monotherapy. Add-on therapy resulted in more viral decline and appeared to prevent relapse after stopping ETV. Hence, Peg-IFN add-on therapy may facilitate the discontinuation of nucleos(t)ide analogs. (Hepatology 2015;61:1512-1522)