In that study, entecavir led to an early and superior reduction in HBV DNA levels compared with adefovir in nucleoside-nave HBeAg-positive patients with CHB (19). DNA and alanine aminotransferase levels. Mean reductions in levels of hepatitis B virus DNA at week 12 were 6.6 1.6 and 6.5 1.5 log10copies/ml for the telbivudine- and entecavir-treated patients, respectively. There were no significant differences between groups in values for mean viral clearance per day, mean loss of infected cells per day, or efficiency of blocking viral production. The safety profiles for both medications were favorable. During the first 12 weeks of treatment, telbivudine and entecavir demonstrated similar antiviral potencies, resulting in a rapid and profound suppression of serum hepatitis B E-4031 dihydrochloride virus DNA and reduction of alanine aminotransferase levels. No differences in the effects of these 2 agents on early viral kinetics were observed. Both medications were well tolerated. Chronic hepatitis B (CHB) affects approximately 350 million individuals worldwide; when left untreated, it may lead to liver-related sequelae including cirrhosis, decompensated liver disease, and hepatocellular carcinoma (2,5,21). Clinical experience has shown that the early and profound suppression of hepatitis B virus (HBV) DNA replication is the primary goal of treatment and that the sustained suppression of serum hepatitis B virus (HBV) DNA levels below the limit of detection is associated with improved long-term virological and biochemical E-4031 dihydrochloride response rates (21,24,40). Therapeutic options for the treatment of patients with CHB have expanded with the licensure of several potent oral nucleoside (nucleotide) analogs (NAs), including entecavir, telbivudine, and tenofovir, that induce a rapid and profound suppression of serum HBV DNA levels. These agents have established superior efficacy over lamivudine and adefovir in large registrational trials (4,15,27); however, limited head-to-head comparative data exist for the more potent NAs in current clinical use (32). An analysis of viral kinetics using established mathematical models during the first few weeks of antiviral therapy is useful for summarizing important features of the early response and provides valuable information by efficient comparisons of different treatment regimens even when relatively small samples are involved (11,31,34). Characterization of early viral kinetics during oral NA treatment can be used to predict E-4031 dihydrochloride E-4031 dihydrochloride subsequent virological responses, allowing clinicians to choose the most appropriate drugs and optimize the patient response to therapy (1,6,14). Data from studies of oral NAs have revealed different patterns of viral kinetics with these agents during the early phase of treatment (16-18,20,28,34). Initial clinical trials of telbivudine have demonstrated profound (>2 log10copies/ml) reductions in serum HBV DNA levels at as early as 1 week of treatment (17). Similar findings were reported for a phase II, 24-week, double-blind study of entecavir in patients with hepatitis B e antigen (HBeAg)-positive CHB (18). The present randomized, open-label, parallel-group, multicenter, phase IIIb trial was conducted to characterize the early viral kinetics, efficacy, Rabbit Polyclonal to MARCH3 and safety of telbivudine and entecavir in treatment-nave patients with HBeAg-positive compensated CHB. The primary objective of this study was to assess reductions in serum HBV DNA levels and changes in other parameters of viral kinetics during 12 weeks of treatment. == MATERIALS AND METHODS == == Study design and patients. == Eligible patients were aged 18 years and had HBeAg-positive CHB with a clinically confirmed diagnosis of compensated liver function (a total serum bilirubin level of 2.5 mg/dl, a prothrombin time 3 s longer than normal or an international normalized ratio of 1 1.5, a serum albumin level of 3 g/dl, and no history of variceal bleeding or hepatic encephalopathy). Eligible patients also had detectable hepatitis B surface antigen (HBsAg) for 24 weeks prior to screening. Other inclusion criteria at screening were serum HBV DNA levels of 7 log10copies/ml, as determined by a Cobas Amplicor DNA PCR-based assay (Roche Molecular Diagnostics, Branchburg, NJ), a E-4031 dihydrochloride serum alanine aminotransferase (ALT) level 1.3 to 10.0 the upper limit of normal (ULN), and evidence of chronic liver inflammation documented upon previous liver biopsy within 24 months of the study or by a history of elevated serum ALT levels on 2 occasions within a 6-month period. Exclusion criteria included coinfection.