Add-on peginterferon alfa-2a to nucleos(t)ide analogue therapy for Caucasian patients with hepatitis B 'e' antigen-negative chronic hepatitis B genotype D

Nucleos(t)ide analogues (NAs) and peginterferon have complementary effects in chronic hepatitis B, but it is unclear whether combination therapy improves responses in genotype D-infected patients. We conducted an open-label study of peginterferon alfa-2a 180 mu g/wk added to ongoing NA therapy in hepatitis B e antigen (HBeAg)-negative, genotype D-infected patients with hepatitis B virus DNA <20 IU/mL. The primary endpoint was proportion of patients with >= 50% decline in serum HBsAg by the end of the 48-week add-on phase. Seventy patients received treatment, 11 were withdrawn at week 24 for no decrease in HBsAg, and 14 withdrew for other reasons. Response rate (per-protocol population) was 67.4% (29/43) at week 48 (95% confidence interval [CI]: 51, 81) and 50.9% (28/55) at week 96 (95% CI: 38, 66). Median serum HBsAg decreased throughout peginterferon alfa-2a treatment and was significantly lower than baseline at weeks 48, 72 and 96 (P < 0.001). Decreases in HBsAg of >= 0.5-log(10) and >= 1-log(10) were documented in 19 (44.2%) and 6 (14.0%) patients at week 48 and 6 (10.9%) and 17 (30.9%) patients at week 96. The proportion of patients with HBsAg <1000, <500, <100 and <10 IU/mL at >= 1 timepoint during treatment was 78.6% (n = 44), 57.1% (n = 32), 21.4% (n = 12) and 7.1% (n = 4). Interferon gamma-induced protein 10 increased from baseline up to week 48, with week 12 levels significantly associated with response at week 48. Addition of peginterferon alfa-2a to ongoing NA therapy significantly decreased HBsAg levels in HBeAg-negative patients with genotype D infection (ClinicalTrials.gov NCT01706575).