Two randomised controlled studies of PEG IFN in patients with HBeAg-positive and HBeAg-negative chronic hepatitis B have confirmed its efficacy with 36 and 43% of 24-week post-treatment response, respectively [35,36]. Interestingly, relatively high rates of HBsAg loss, which are associated with complete and sustained remission of the disease, were observed in both studies
[3% (HBeAg-positive) and 4% (HBeAg-negative)] as compared with < 1% in patients treated with lamivudine.
Recently, follow-up data of this trial reported responses at 3 years post treatment [38]. Biochemical and virologic responses at 3 years post treatment were stable following treatment with either PEG IFN monotherapy or in combination
with lamivudine. In addition, at 3 and 4 years post treatment, an increase in HBsAg loss was observed in 8 and 11% of patients, respectively.
Tenofovir
Two multi-centre, randomised,
double-blind, Phase III clinical trials evaluated the safety and efficacy of 300 mg tenofovir versus 10 mg adefovir at 48 weeks in subjects with HBeAg-positive (n = 266) and HBeAg-negative (n = 375) chronic HBV [57,58]. In HBeAg-positive, chronic HBV patients, tenofovir clearly demonstrated superior efficacy to adefovir through 48 weeks as illustrated by the higher percentage of undetectable HBV DNA levels [74% (tenofovir) versus 12% (adefovir)] and normalisation of ALT levels [69% (tenofovir) versus 54% (adefovir)]. Interestingly, HBsAg loss was observed in 3% of patients after 48 weeks of tenofovir therapy. Similar results were observed in HBeAg-negative chronic HBV patients: tenofovir showed a higher antiviral efficacy than adefovir after 48 weeks of therapy.
