Randomized prospective study showing the non-inferiority of tenofovir to entecavir in treatment-naïve chronic hepatitis B patients

Aim: The study aimed to evaluate the efficacy and safety of tenofovir disoproxil fumarate (TDF) and entecavir hydrate (ETV) in nucleos(t)ide analog (NA)-naïve Japanese chronic hepatitis B (CHB) patients.

Methods: This multicenter, randomized, double-blinded study assessing the efficacy and safety of TDF 300 mg and ETV 0.5 mg in NA-naïve CHB subjects was carried out from November 2011 to November 2014, and funded by GlaxoSmithKline. The subjects were assigned to the TDF arm or ETV arm in a 2:1 ratio. The primary efficacy endpoint was the non-inferiority of TDF to ETV at week 24.

Results: A total of 166 subjects (TDF arm, 110; ETV arm, 56) were enrolled. The change (mean ± SE) in serum hepatitis B virus (HBV)-DNA levels from baseline to week 24 was -4.63 ± 0.044 and -4.50 ± 0.063 log₁₀ copies/mL in the TDF and ETV arms, respectively, indicating the non-inferiority of TDF to ETV (P < 0.0001). The proportion of subjects with undetectable HBV-DNA increased from 54 to 77% and 39 to 66% in the TDF and ETV arms with continuation of the treatment from week 24 to 48, respectively. Reduction in hepatitis B surface antigen level was greater in subjects with hepatitis B envelope antigen (+) and high alanine aminotransferase levels (≥80 IU/L). Prevalence of drug-related adverse events at week 48 was 20% and 18% in the TDF and ETV arms, respectively.

Conclusions: The study is the first to report that TDF has non-inferiority to ETV in treatment effectiveness (lowering of serum HBV-DNA level) at week 24. ClinicalTrials.gov trial registration nos. NCT01480284 and GSK LOC115409.