One hundred and ninety-two weeks treatment of entecavir maleate for Chinese chronic hepatitis B predominantly genotyped B or C

Abstract

Background: Entecavir (ETV) is a potent and selective nucleotide analog with significant activity against hepatitis B virus (HBV). ETV maleate is a derivative compound of ETV and was reported to have an efficacy and safety profile that is comparable to ETV (Baraclude) when used in Chinese patients with chronic hepatitis B (CHB) in phase III clinical trials (Clinical Trials.gov number, NCT01926288) at weeks 48, 96, and 144.

Aim: To investigate the antiviral potency and safety of ETV maleate at week 192 in Chinese CHB patients predominantly genotyped B or C.

Methods: In this double-blind study, we randomly assigned patients to receive 0.5 mg/d ETV (Group A) or ETV maleate (Group B) (ratio, 1:1), each with a placebo tablet for 48 wk. Then, all patients received open-label treatment with 0.5 mg/d ETV maleate starting at week 49. The primary efficacy endpoint was the reduction in HBV DNA levels from baseline. Secondary endpoints included the proportion of patients with undetectable HBV DNA (< 20 IU/mL), serologic response, serum alanine aminotransferase (ALT) normalization and development of resistance mutations.

Results: Two hundred eighteen patients who were hepatitis B e antigen (HBeAg) positive and 57 who were HBeAg negative were analyzed and predominantly presented with genotype B (49.82%) or C (48.73%). For the HBeAg-positive CHB patients, the mean HBV DNA level decrease (6.61 Log₁₀ IU/mL vs 6.69 Log₁₀ IU/mL, P > 0.05), viral suppression with HBV DNA < 20 IU/mL (83.33% vs 79.17%, P > 0.05) and HBeAg seroconversion (28.77% vs 20.00%, P > 0.05) occurred similarly between Groups A and B at week 192. However, there was a significant difference in the proportion of patients with normal ALT levels (91.14% vs 78.38%, P < 0.05). For the HBeAg-negative CHB patients, no significant difference was found between Groups A and B at week 192 in terms of reductions in HBV DNA levels from baseline (6.05 Log₁₀ IU/mL vs 6.03 Log₁₀ IU/mL, P > 0.05), percentages of patients who achieved undetectable HBV DNA (100% vs 100%, P > 0.05) and rates of ALT normalization (95.65% vs 100.00%, P > 0.05). Safety and adverse event profiles were similar between Groups A and B. Two HBeAg-positive patients in Group A and 5 in Group B developed genotypic resistance to ETV.

Conclusion: Long-term ETV maleate treatment for up to 192 wk is effective and safe in Chinese CHB patients predominantly genotyped as B or C.

Keywords: Chronic hepatitis B; Entecavir maleate; Genotype; Mutation; Randomized controlled trial; Treatment outcome.