HBsAg clearance in chronic hepatitis B patients with add-on pegylated interferon alfa-2a to ongoing tenofovir treatment: A randomized controlled study

BACKGROUND/AIMS The ideal end point of treatment for chronic hepatitis B virus (HBV) infection is sustained off-therapy hepatitis B surface antigen (HBsAg) loss with or even without seroconversion to anti-HBs. We investigated the role of adding PEGylated interferon (PEG IFN) to ongoing tenofovir treatment in chronic HBV patients for achieving HBsAg clearance. PATIENTS AND METHODS In this randomized controlled trial, chronic HBV patients who have been receiving tenofovir for >6 months with HBV viral load <2000 IU/ml were randomized into two groups. One group (add-on therapy) was given subcutaneous PEG IFN 180 mcg weekly for 12 months in addition to tenofovir. Patients in the other group received only tenofovir 300 mg orally on a daily basis. Patients in both groups were followed up for a total of two years, and patients in both groups were given tenofovir 300 mg daily indefinitely until they developed HBsAg clearance. RESULTS Twenty-three patients were allocated to the PEG IFN and tenofovir (add-on therapy) group, and another 25 patients were recruited to the tenofovir monotherapy group. Before randomization, patients had received tenofovir for 1135 mean days (range203 to 1542 days). One patient (4.3%) in add-on therapy lost HBsAg and seroconverted. Within two years, mean HBsAg decreased significantly with add-on therapy (from 4753 IU/ml to 2402; P= 0.03); and it decreased from 5957 IU/ml to 4198; P= 0.09 in tenofovir monotherapy group. More patients in the add-on group developed serious side effects, with treatment discontinuation, and dose reductions (P = 0.3). CONCLUSION PEG IFN and tenofovir add-on therapy was successful in achieving HBsAg clearance and seroconversion in 4.3% of the patients. Add-on therapy patients had a significant decrease in HBsAg levels in two years; and no significant decrease in HBsAg levels with the tenofovir monotherapy. With no significant HBsAg clearance, the utility of this combination regimen is questionable.