Recombinant human gamma-interferon in patients with chronic active hepatitis B: pharmacokinetics, tolerance and biological effects

Pharmacokinetics, tolerance and biological effects of human recombinant gamma-interferon were studied in 12 patients with chronic active hepatitis B. Serum concentrations of gamma-interferon were measured by radioimmunoassay in four patients after a subcutaneous injection of 10 million U (0.5 mg); the peak serum concentration of gamma-interferon (29 +/- 7 U/ml) was reached after 5 to 8 hr and gamma-interferon remained detectable for 24 to 36 hr. Twelve patients received recombinant gamma-interferon, 2.5 to 10 million U daily, for 4 mo. All suffered from a dose-dependent, flulike syndrome similar to that induced by alpha-interferon. Recombinant gamma-interferon induced a marked increase of serum ALT and a significant decrease of serum hepatitis B virus-DNA. Serum hepatitis B virus-DNA disappeared in one patient during administration of recombinant gamma-interferon. Serum hepatitis B virus-DNA disappeared in four additional patients, and HBeAg disappeared in two patients during the 12 mo after administration of recombinant gamma-interferon. These results indicate that subcutaneous injection is suitable for administration of recombinant gamma-interferon and that recombinant gamma-interferon has an antiviral effect in patients with chronic active hepatitis B.