Consensus Interferon in Combination with Gamma Interferon and/or Ribavirin Results in a Significant Virologic Response in Hepatitis C Genotype 1 Patients

Although sustained response rates of about 50% are seen in chronic HCV patients using peginterferon plus ribavirin, the response is lower among genotype 1 HCV patients.

A pilot study of consensus interferon (Infergen) plus gamma interferon has demonstrated increase efficacy over peginterferon alone in treatment with pegylated interferon alfa and ribavirin has demonstrated increased efficacy in nonresponders to peginterferon.

In the present study, researchers in Germany evaluated the efficacy of daily dosing with either gamma interferon and/or ribavirin in 60 treatment-naïve patients with genotype 1 chronic hepatitis C.

Study participants received consensus interferon 9 micrograms daily for 48 weeks. Treatment was supplemented with gamma IFN at 50 microgram TIW   and/or weight-based RBV with 11 mg/kg BW.

Results

• At 48 weeks therapy (ETR) an undetectable HCV-RNA was observed in 74% of the CIFN/RBV group, in 71% of the CIFN/gamma IFN group and 81% of the CIFN/RBV/gamma IFN group.
  
  
• Due to side effects CIFN had to be dose reduced in 7% and discontinued in 3% of all patients.
  
  
• RBV had to be dose reduced in 11% of all patients, while gamma IFN was not dose reduced.
  
  
• When viral response rates were related to the initial viral load, in the genotype 1 / low viral load group, SVR rates of 59, 52, and 64% were obtained for the CIFN/RBV, CIFN/gamma IFN and CIFN/RBV/gamma IFN groups, respectively (p=n.s. in all comp.).
  
  
• In contrast, genotype 1 / high viral load patients showed response rates for the CIFN/RBV, CIFN/gamma IFN and CIFN/RBV/gamma IFN groups of 46, 48 and 57%, respectively.
  
  
• 5 patients in treatment arms with gamma IFN experienced grade III neutropenias, while no grade IV neutropenias or thrombocytopenias were observed.
  
  
• In contrast, no significant hemoglobin drop was noted in the CIFN/gamma IFN arm. The overall tolerability was comparable to a standard therapy with pegylated interferon and RBV, while the tolerability of the three treatment arms was best in the CIFN/gamma IFN arm.

The authors conclude “CIFN daily dosing therapy in combination with gamma IFN and/or RBV thus shows significant response rates in genotype 1 patients.

“The response rates for CIFN and gamma RBV are as high as with CIFN and RBV, while triple therapy leads to even higher response rates by lowering the relapse rate.”

“These data suggest that gamma IFN may be an effective supplement for RBV or additive in alpha IFN / RBV therapy especially for difficult-to-treat genotype 1 / high viral load patients or patients with bad tolerability or contraindications for RBV.

11/14/05

Reference
S Kaiser and others. Consensus Interferon in combination with Gamma Interferon and/or Ribavirin leads to a significant response in treatment-naive Hepatitis C Genotype 1 patients. Abstract 66839. 56^th annual meeting of the American Association for the Study of Liver Diseases (56^th AASLD). November 11-15, 2005. San Francisco, CA.