Objective: To evaluate the efficacy and safety of tenofovir disoproxil fumarate (TDF) in patients with chronic hepatitis B (CHB) after failure of nucleoside-analogues (NAs).
Methods: A total of 30 CHB patients who had been previously treated with NAs and had subsequently completed a 48-week course of TDF were retrospectively investigated. Patients' data of HBV DNA level (log10 copies/ml) and rate of undetectable HBV DNA at treatment weeks 0 (baseline), 4, 12, 24, 36 and 48 were collected for evaluation. The lower limit of HBV DNA detection was 100 IU/ml. The serum alanine aminotransferase (ALT) normalization rate, hepatitis B e antigen (HBeAg) seroconversion rate, viral breakthrough (VBT) rate, viral response (VR) rate, and adverse events were determined upon treatment completion. Statistical analyses were carried out using the Student's t-test, the x² test or the Kaplan-Meier method.
Results: Over the 48-week treatment period, HBV DNA levels declined significantly from baseline (week 4:(2.11 ± 0.38) log10 IU/ml, t =5.582; week 12:(0.93 ± 0.31) log10 IU/ ml, t =9.303; week 24:(0.75 ± 0.20) log10 IU/ml, t =3.123; week 36:(0.16 ± 0.19) log10 IU/ml, t =10.759; week 48:(0.14 ± 0.25) log10 IU/ml, t =12.202) (all P less than 0.01). However, the rates of HBV DNA reduction and of cumulative reduction were comparable at weeks 24, 36 and 48 (all P more than 0.05). The most robust decline in HBV DNA levels was observed at week 4 ((2.11 ± 0.38) log10 IU/ml) and the highest cumulative HBV DNA reduction was observed at week 24 ((3.79 ± 0.37) log10 IU/ml). The rate of undetectable HBV DNA at week 4 (26.7%) was significantly lower than that at weeks 24 (87.5%, P less than 0.01), 36 (80.0%, P=0.007), and 48 (88.9%, P=0.001). The median time to achieving undetectable HBV DNA was 10.4 weeks (range:3.43-34.0 weeks). At week 48, the rates of VR, HBeAg seroconversion, and VBT were 88.9% ,6.7%, and 0% respectively. During treatment, the levels of creatine kinase were more than two times the upper limit normal in 9.2% of the patients, and were comparable at each time point examined (all P more than 0.05). All patients showed a normal level of serum creatinine throughout the treatment period.
Conclusion: For CHB patients with non-response to NAs, TDF can suppress HBV DNA replication very quickly and achieve a high rate of ALT normalization with a low rate of adverse events.