Rescue Monotherapy in Lamivudine-Resistant Hepatitis B e Antigen-Positive Chronic Hepatitis B: Adefovir versus Entecavir

Abstract

The efficacy of adefovir dipivoxil (ADV) or entecavir (ETV) rescue monotherapy has not been directly compared in hepatitis B e antigen (HBeAg)-positive patients with lamivudine (3TC)-resistant chronic hepatitis B (CHB). We compared the efficacy of ADV and ETV rescue monotherapy in HBeAg-positive patients with confirmed genotypic 3TC resistance. A total of 160 HBeAg-positive patients with confirmed 3TC resistance underwent switch therapy (91 ADV and 59 ETV). Parameters assessed included alanine aminotransferase (ALT) normalization, HBeAg seroconversion, undetectable serum hepatitis B virus (HBV) DNA by PCR (lower detection limit <300 copies/ml), virological breakthrough and initial virological response (IVR) at 3 (IVR-3) and 6 (IVR-6) months. Following 52 weeks of treatment in the ADV and ETV groups, serum HBV DNA became undetectable in 25 (27.5%) and 21 (35.6%; P=0.292) patients, ALT normalization occurred in 67/78 (85.9%) and 43/47 (91.5%; P=0.351), HBeAg seroconversion in 4 (4.4%) and 1 (1.7%; P=1.000), IVR-3 in 19 (20.9%) and 18 (30.5%), IVR-6 in 40 (44.0%) and 25 (42.4%) and virological breakthrough in 2 (2.2%) and 1 (1.7%; P=1.000) patients, respectively. ADV and ETV revealed comparable efficacy after 52 weeks of treatment in HBeAg-positive patients with 3TC resistance. Undetectable HBV DNA in serum following 52 weeks of treatment was predictable with IVR-3 and IVR-6 in both groups.