A controlled study to determine the optimal dose regimen of interferon-alpha 2b in chronic hepatitis C

The efficacy of three different dose treatments of interferon (IFN) was evaluated in patients with chronic hepatitis C (HCV).

Ninety-one patients with chronic hepatitis C were allocated to receive 3, 6, or 10 U of recombinant IFN-alpha 2b three times weekly for 24 wk. The number of patients was 26, 35, and 30 in the low, middle, and high dose groups, respectively. Treatment was discontinued, however, in four patients (one in the middle dose group and three in the high dose group) because of depression occurring 1-3 months after therapy began. A total of 87 patients, therefore, was analysed and was comprised of 26 patients in the low dose group, 34 in the middle dose group, and 27 in the high dose group.

At the end of treatment, serum levels of ALT were normal in 50% (13/26) of patients in the low dose group, 70% (24/34) in the middle dose group, and 74% (20/27) in the high dose group. Patients with persistent normalization of ALT for 12 months of follow-up were defined as sustained responders. Twelve months after treatment cessation, the percentage of sustained responders was 23% (6/23) in the low dose group, 44% (15/34) in the middle dose group, and 41% (11/27) in the high dose group. Including the four patients who required discontinuation of IFN administration, the percentage of sustained responders was 43 and 37% in the middle and high dose groups, respectively. The clearance of HCV RNA was 40% in the middle dose group and 33% in the high dose group. This decrease in the clearance of HCV RNA was prominent in the high dose group. The percentage tended to be higher in the middle dose group, but the differences were not significant.

The results suggest that a regimen of recombinant IFN-alpha 2b in a dose of 6 U three times weekly for 24 wk may be appropriate for the treatment of chronic HCV.