Hepatitis B Surface Antigen Loss with Tenofovir Disoproxil Fumarate Plus Peginterferon Alfa-2a: Week 120 Analysis

Background and Aims: Hepatitis B surface antigen (HBsAg) loss is the ideal clinical endpoint but is achieved rarely during oral antiviral treatment. A current unmet need in CHB management is achievement of HBsAg loss with a finite course of oral antiviral therapy, thereby allowing discontinuation of treatment. Significantly higher rates of HBsAg loss at 72 weeks post-treatment have been demonstrated when tenofovir disoproxil fumarate (TDF) was combined with pegylated interferon (PEG-IFN) for 48 weeks compared with either monotherapy. This analysis provides follow-up data at week 120. Methods: In an open-label, active-controlled study, 740 patients with chronic hepatitis B were randomly assigned to receive TDF plus PEG-IFN for 48 weeks (group A), TDF plus PEG-IFN for 16 weeks followed by TDF for 32 weeks (group B), TDF for 120 weeks (group C), or PEG-IFN for 48 weeks (group D). Efficacy and safety at week 120 were assessed. Results: Rates of HBsAg loss at week 120 were significantly higher in group A (10.4%) than in group B (3.5%), group C (0%), and group D (3.5%). Rates of HBsAg loss and HBsAg seroconversion in group A were significantly higher than rates in group C (P < 0.001 for both) or group D (HBsAg loss: P = 0.002; HBsAg seroconversion: P < 0.001). Conclusions: The results of this analysis confirm the results from earlier time points which demonstrate the increased rate of HBsAg loss in patients treated with a finite course of PEG-IFN plus TDF compared with the rates in patients receiving either monotherapy.