Long-term virological outcome in chronic hepatitis B patients with a partial virological response to entecavir

The clinical outcome of patients with a partial virological response (PVR) to entecavir (ETV), in particular nucloes(t)ide analogue (NA)-experienced patients, has not been thoroughly investigated. The aim of the present study was to assess long-term outcomes in NA-naive and NA-experienced chronic hepatitis B patients with a PVR to ETV.

Chronic hepatitis B patients treated with ETV (0.5 mg/day) for at least 1 year were enrolled retrospectively. PVR was defined as a decrease in hepatitis B virus (HBV) DNA titer of more than 2 log10 IU/mL, yet with residual serum HBV DNA, as determined by real time-polymerase chain reaction, at week 48 of ETV therapy.

A total of 202 patients (127 NA-naive and 75 NA-experienced, male 70.8%, antigen positive 53.2%, baseline serum HBV DNA 6.2 ± 1.5 log10 IU/mL) were analyzed. Twenty-eight patients demonstrated a PVR. The PVR was associated with a high serum HBV DNA titer at baseline and at week 24. Virological response (< 60 IU/mL) was achieved in 46.2%, 61.5%, 77.6%, and 85% of patients with PVR at week 72, 96, 144, and 192, respectively. Resistance to antivirals developed in two NA-experienced patients. Failure of virological response (VR) in patients with PVR was associated with high levels of serum HBV DNA at week 48.

Patients with PVR to ETV had favorable long-term virological outcomes. The low serum level of HBV DNA (< 200 IU/mL) at week 48 was associated with subsequent development of a VR in patients with PVR to ETV.