Background/Aims
Entecavir is a potent and selective guanosine analogue that has demonstrated a significant antiviral efficacy against hepatitis B virus (HBV). The aim of this study was to characterize the response to entecavir and to examine the factors affecting that response. Methods: We administered 0.5 mg of entecavir once daily for more than 12 months to 114 naive chronic hepatitis B (CHB) patients. We measured the levels of liver enzymes, serological markers, and serum HBV DNA at 3-month interval. Results: Normalization of serum alanine aminotransferase levels was observed in 68.5% (76/114), 74.6% (85/114), and 81.6% (62/76) of patients after 6, 12, and 24 months of therapy, respectively. HBV DNA levels of <50 copies/mL (as evaluated by polymerase chain reaction) were observed in 43.9% (50/114), 71.1% (81/114), and 85.5% (65/76) of patients after 6, 12, and 24 months, respectively. Viral breakthrough was not observed. The rates of HBeAg loss and seroconversion were 43.5% (27/62) and 14.5% (9/62), respectively, after 12 months of therapy, and 56.4% (22/39) and 15.4% (6/39) after 24 months. The independent factor associated with PCR negativity was early virologic response (EVR; HBV DNA <2,000 copies/mL after 3 months of therapy, P<0.001). The independent factors predicting HBeAg loss were found to be serum albumin levels (P=0.041) and EVR (P=0.005). Conclusions: Entecavir induced excellent biochemical and virologic responses in naive CHB patients. EVR was an independent factor for predicting HBV PCR negativity and HBeAg loss. (Korean J Hepatol 2009;15:446-453)
