Virologic Response To Pegasys With Genotype 4 in Small Study Group

Morris Sherman from Toronto General Hospital reported at I think AASLD November, 2000 response to Pegasys and regular Interferon a-2a for individuals with chronic HCV and genotype 4.

It has been reported that treatment with standard IFN is less effective in patients with genotypes 1 and 4 than in patients with genotypes 2 and 3. The purpose of this retrospective analysis was to compare the effectiveness of Pegasys (40 kDa) IFN a-2a once weekly with IFN a-2a taken 3 times weekly in patients chronically infected with hepatitis C with the difficult to treat genotype 4. The investigators looked at a database consisting of 1208 patients from large randomized phase II and III studies comparing three times weekly injections of IFN a-2a (3 MIU or 6 MIU) to treatment with once weekly Pegasys IFN a-2a (180 ug). Effectiveness was evaluated in a subset of patients infected with genotype 4.

Sixteen patients were found to have genotype 4. Five patients received treatment with IFN a-2a three times weekly and 11 were treated with 180 ug Pegasys IFN a-2a once weekly for up to 48 weeks. Patients were predominantly male (63%), with baseline viral loads ranging from 8,000 to >12 million copies/ml (COBAS Amplicor Monitor HCV, version 2.0). Four patients (25%) had cirrhosis. End-of-treatment (week 48) virologic responses (COBAS Amplicor HCV Test version 2.0 with lower limit of detection of 100 copies/ml) were 0% in the standard IFN a-2a patients and 73% in the Pegasys group. Sustained virologic response (week 72) was obtained on 0% of patients receiving standard IFN and 45% in Pegasys treated patients. All patients that were sustained virologic responders were also sustained biochemical responders. Paired biopsies (pre and post treatment) were obtained for 8 patients treated with Pegasys and histologic response (improved liver condition) measured by a >2 point decrease in Histology Activity Index (HAI) was found in 5 of these patients (63%). Histologic response was observed in 2/3 patiented with paired biopsies and treated with standard IFN.

The authors concluded that the number of patients with genotype 4 found to respond well to Pegasys was small, but the data are encoraging and indicate that further larger studies should be conducted in genotype 4 patients.