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BackgroundThe glycosphingolipid α-galactosylceramide (α-GalCer) is known to stimulate invariant natural killer T-cells (iNKTs) and is able to induce powerful antiviral immune responses. The present dose-escalating randomized placebo-controlled Phase I/II trial aimed to investigate antiviral activity and safety of α-GalCer as a novel class of treatment for chronic hepatitis B patients.MethodsPatients were randomly assigned to 0.1 μg/kg ( n=8), 1 μg/kg ( n=6) or 10 μg/kg ( n=6) α-GalCer or placebo ( n=7) treatment.ResultsAlmost all α-GalCer-treated patients showed a rapid and strong decrease in natural killer T-cell (NKT) numbers. Patients with high baseline NKT numbers showed immune activation, including natural killer cell activation, increased serum tumour necrosis factor-α and interleukin-6 levels, and development of fever. Three patients demonstrated a transient decrease in hepatitis B virus (HBV) DNA. Only one α-GalCer-treated patient had a sustained decrease in HBV DNA at the end of follow-up. Four patients discontinued therapy because of fever shortly after drug administration. No significant side effects were observed.Conclusionsα-GalCer (0.1–10 μg/kg) used as mono-therapy for chronic hepatitis B infection resulted in a strong decrease of NKTs, but did not clearly affect HBV DNA and alanine aminotransferase levels. α-GalCer was poorly tolerated and is unlikely to be suitable as an alternative monotherapy to the current treatment regimen.

Background Pegylated interferon α2b (PEG-IFN-α2b) is effective for the treatment of hepatitis B e antigen (HBeAg)-positive chronic hepatitis B, although its mechanism of action remains unclear. HBeAg loss is achieved in 36% of patients after one year of PEG-IFN-α2b treatment and combination therapy with lamivudine is not superior to PEG-IFN-α2b monotherapy. Methods Early pharmacokinetics and viral kinetics were analysed in patients treated for 52 weeks with PEG-IFN-α2b with or without lamivudine. Results After 4 weeks of treatment, there was a median viral decline of 2.94 log10 copies/ml in those treated with PEG-IFN-α2b and lamivudine and only 0.45 log10 copies/ml in the PEG-IFN-α2b monotherapy group. Peak PEG-IFN-α2b levels were reached approximately one day after administration and subsequently declined exponentially, consistent with a viral load rebound near to baseline levels at the end of the dosing period in most patients receiving PEG-IFN-α2b monotherapy. Modelling of pharmacokinetics and viral kinetics data in this group revealed that viral load was minimal 3.6 days after PEG-IFN-α2b administration, the mean maximal and mean antiviral effectiveness was 70% and 48% with a mean infected cell loss rate of 0.07 per day, while no significant biphasic decline was observed. Conclusions PEG-IFN-α2b induces a sustained response in a considerable number of patients despite limited direct antiviral activity during the first weeks of antiviral therapy.

Pegylated interferon alpha2b (PEG-IFN-alpha(2b) is effective for the treatment of hepatitis B e antigen (HBeAg)-positive chronic hepatitis B, although its mechanism of action remains unclear. HBeAg loss is achieved in 36% of patients after one year of PEG-IFN-alpha2b treatment and combination therapy with lamivudine is not superior to PEG-IFN-alpha2b monotherapy.Early pharmacokinetics and viral kinetics were analysed in patients treated for 52 weeks with PEG-IFN-alpha2b with or without lamivudine.After 4 weeks of treatment, there was a median viral decline of 2.94 log10 copies/ml in those treated with PEG-IFN-alpha2b and lamivudine and only 0.45 log10 copies/ml in the PEG-IFN-alpha2b monotherapy group. Peak PEG-IFN-alpha2b levels were reached approximately one day after administration and subsequently declined exponentially, consistent with a viral load rebound near to baseline levels at the end of the dosing period in most patients receiving PEG-IFN-alpha2b monotherapy. Modelling of pharmacokinetics and viral kinetics data in this group revealed that viral load was minimal 3.6 days after PEG-IFN-alpha2b administration, the mean maximal and mean antiviral effectiveness was 70% and 48% with a mean infected cell loss rate of 0.07 per day, while no significant biphasic decline was observed.PEG-IFN-alpha2b induces a sustained response in a considerable number of patients despite limited direct antiviral activity during the first weeks of antiviral therapy.