['To investigate the relationship between the degree of week 24 HBV suppression and week 48 therapeutic response in entecavir-treated chronic hepatitis B patients in whom lamivudine treatment failed, so as to explore a useful predictor for efficacy of enticavir treatment.', 'Thirty-three patients with chronic hepatitis B refractory to lamivudine were enrolled to receive treatment with entecavir 1.0 mg once daily. The patients were divided into 4 groups according to serum HBV DNA levels (copies/mL) at week 24: PCR-undetectable (less than 300 copies/ml); QL- less than 3 log10 copies/ml; 3 log10(-4) log10 copies/ml; greater than 4 log10 copies/mL, and the efficacy achieved at week 48 was evaluated.', 'At week 48, mean reductions of serum HBV DNA from baseline was 4.91 log10. HBV DNA became undetectable by PCR assay in 33.3 percent patients and ALT became normal in 75.8%. The lower the HBV DNA level achieved at week 24, the higher the proportion of patients in whom HBV DNA became undetectable by PCR and ALT normalization were acquired at week 48, and viral breakthrough at week 48 also decreased.'] Is [ Week 24 suppression of HBV in entecavir-treated chronic hepatitis B patients in whom lamivudine treatment failed associated with efficacy at week 48 ]?