Peginterferon alfa-2a results in a sustained response (SR) in a minority of patients with hepatitis B e antigen (HBeAg)-negative chronic hepatitis B (CHB). This study investigated the role of early on-treatment serum hepatitis B surface antigen (HBsAg) levels in the prediction of SR in HBeAg-negative patients receiving peginterferon alfa-2a. HBsAg (Architect from Abbott) was quantified at the baseline and during treatment (weeks 4, 8, 12, 24, 36, and 48) and follow-up (weeks 60 and 72) in the sera from 107 patients who participated in an international multicenter trial (peginterferon alfa-2a, n 5 53, versus peginterferon alfa-2a and ribavirin, n 5 54). Overall, 24 patients (22%) achieved SR [serum hepatitis B virus (HBV) DNA level < 10,000 copies/mL and normal alanine aminotransferase levels at week 72]. Baseline characteristics were comparable between sustained responders and nonresponders. From week 8 onward, serum HBsAg levels markedly decreased in sustained responders, whereas only a modest decline was observed in nonresponders. However, HBsAg declines alone were of limited value in the prediction of SR [area under the receiver operating characteristic curve (AUC) at weeks 4, 8, and 12 5 0.59, 0.56, and 0.69, respectively]. Combining the declines in HBsAg and HBV DNA allowed the best prediction of SR (AUC at week 12 5 0.74). None of the 20 patients (20% of the study population) in whom a decrease in serum HBsAg levels was absent and whose HBV DNA levels declined less than 2 log copies/mL exhibited an SR (negative predictive value 5 100%). Conclusion: At week 12 of peginterferon alfa-2a treatment for HBeAg-negative CHB, a solid stopping rule was established with a combination of declines in serum HBV DNA and HBsAg levels from the baseline. Quantitative serum HBsAg in combination with HBV DNA enables on-treatment adjustments of peginterferon therapy for HBeAg-negative CHB. (HEPATOLOGY 2010;52:454-461)

,15 for the ARES Study Group 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 mg/week) from week 24 to 48 (n 5 85) or to continue ETV monotherapy (n 5 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 5 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 5 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 5 0.007), which was 79% (11 of 14) versus 25% (2 of 8) of those who discontinued ETV (P 5 0.014). At week 96, 22 (26%) patients assigned add-on versus 12 (13%) assigned monotherapy achieved HBeAg seroconversion (P 5 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

ClinicalTrials.gov Identifier: NCT00736983.

Treatment with peginterferon alpha-2a resulted in a limited sustained response rate in HBeAg-negative chronic hepatitis B patients. Addition of ribavirin did not improve response to therapy.