A 24-Week, Parallel-Group, Open-Label, Randomized Clinical Trial Comparing the Early Antiviral Efficacy of Telbivudine and Entecavir in the Treatment of Hepatitis B e Antigen-Positive Chronic Hepatitis B Virus Infection in Adult Chinese Patients

Background: Because drug-resistant strains of hepatitis B virus (HBV) have developed, and because serum HBV-DNA levels may rebound in patients who receive treatment with nucleoside/nucleotide analogues for up to 2 years, there remains a largely unmet clinical need for agents to induce potent virologic suppression in the initial stage of the disease course of HBV infection. Objective: The aim of this work was to compare the early antiviral effectiveness of telbivudine and entecavir in the treatment of patients with hepatitis B e antigen (HBeAg)-positive HBV. Methods: In this parallel-group, open-label trial, adult Chinese patients with previously untreated HBeAg-positive HBV (HBV-DNA concentration: >= 6 log(10) copies/mL; alanine aminotransferase [ALT] level: >= 2 times the upper limit of normal) were randomized to receive telbivudine 600 mg or entecavir 0.5 mg daily for 24 weeks. Blood samples were collected at the baseline and at 12 and 24 weeks after the treatment. The primary end point was the mean reduction from baseline in serum HBV-DNA concentration at week 24. Secondary end points included mean reduction from baseline in serum HBV-DNA concentration at week 12, the absence of serum HBV-DNA, absence of serum HBeAg, HBeAg seroconversion at week 24, the normalization of serum ALT at week 24, and occurrence of adverse events through week 24. Results: A total of 131 patients were enrolled in the study: 91 men and 40 women, with a mean (SD) age of 32.5 (8.9) years. All patients were ethnic Han Chinese. The baseline demographic characteristics and serum HBV-DNA concentrations in the 2 treatment groups were well matched. Sixty-five patients were randomized to receive telbivudine and 66 to receive entecavir. The mean reductions from baseline in serum HBV-DNA were 4.99 and 4.69 log(10) copies/mL at week 12, respectively, and 6.00 and 5.80 log(10) copies/mL at week 24 (both time points, P = NS between groups). At week 12, HBV-DNA was undetectable in 43.1% (28/65) of the telbivudine group and 34.8% (23/66) of the entecavir group (P = NS); at week 24, it was undetectable in 67.7% (44/65) of the telbivudine group and 57.6% (38/66) of the entecavir group (P = NS). At week 12, HBeAg absence and seroconversion rates were significantly greater in the telbivudine group than the entecavir group (absence: 20.0% [13/65] vs 3.0% [2/66], respectively [P = 0.002]; seroconversion: 13.8% [9/65] vs 3.0% [2/66] [P = 0.030]). However, at week 24, HBeAg absence and seroconversion rates were comparable between the telbivudine and entecavir groups (absence: 36.9% [24/65] vs 28.8% [19/66] [P = NS]; seroconversion: 24.6% [16/65] vs 13.6% [9/66] [P = NS]). In addition, the normalization of ALT levels was observed in 78.5% (51/65) and 74.2% (49/66) of patients treated with telbivudine and entecavir, respectively, at week 24 (P = NS). The adverse events were upper respiratory tract infection (12.3% of telbivudine patients vs 9.1% of entecavir patients), fatigue (6.2% vs 7.6%), diarrhea (1.5% vs 3.0%), and coughing (0% vs 1.5%), most of which were mild to moderate. Elevated creatinine phosphokinase was noted in 8 telbivudine-treated patients (12.3%). There were no statistically significant differences in rates of adverse events between groups except for creatinine phosphokinase. Conclusion: In this study of ethnic Han Chinese adults with previously untreated HBeAg-positive HBV infection, there were no statistically significant differences in effectiveness or tolerability between telbivudine 600 mg and entecavir 0.5 mg at the end of 24 weeks of treatment. ChiCTR.org identifier: ChiCTR-TRC-00000341. (Clin Ther. 2010;32:649-658) (C) 2010 Excerpta Medica Inc.