Consensus Interferon Produces Sustained Response in Some Non-responders and Relapsers to Prior Interferon-based Therapy

About half of chronic hepatitis C patients who receive the current standard therapy of pegylated interferon alfa plus ribavirin do not achieve sustained virological response, or continued undetectable HCV viral load 24 weeks after completing treatment.

There is currently no FDA-approved treatment for prior non-responders or relapsers to pegylated interferon plus ribavirin, but several new therapies are under study. One of these, consensus interferon (Infergen), has yielded mixed results in clinical trials. Consensus interferon is a recombinant molecule that combines the most common amino acids in various subtypes of interferon alfa.

As reported at the recent 58th Annual Meeting of the American Association for the Study of Liver Diseases (AASLD 2007) in Boston (November 2-6, 2007), researchers conducted a retrospective review of use of consensus interferon (with or without ribavirin) in "real world" clinical practice within the Veterans Administration (VA) healthcare system between 2003 and 2006.

Results

• 776 patients were prescribed consensus interferon, almost all (>99%) in combination with ribavirin.

• Patients were predominantly male (95%), with a mean age of about 55 years; about 40% were Caucasian, 26% were African American, 4% were Hispanic, and 30% were of "other/unknown" race/ethnicity.

• The majority who received consensus interferon were prior non-responders or relapsers to pegylated interferon plus ribavirin, with an average 9-month duration of prior pegylated interferon use.

• Out of 134 VA medical facilities, 73 (55%) did not prescribe consensus interferon at all.

• In the remaining 61 prescribing facilities, there was a 15-fold difference in patients receiving consensus interferon between the lowest and highest quartiles of prescribers.

• More than half (57%) of patients discontinued consensus interferon within 3 months, yielding an average treatment duration of 3.1 months.

• Among patients with available virological response data, 12% had undetectable HCV RNA ? 3 months after completion of treatment.

• Sustained response rates were higher for prior non-responders/relapsers, at 24%.

Conclusion

"[C]onsensus interferon is being used frequently, primarily in combination with ribavirin, in prior non-responders to peginterferon plus ribavirin," the researchers concluded. "These data, from diverse clinical practice settings, are encouraging results for patients who are non-responders/relapsers to peginterferon plus ribavirin. Further study is required to examine factors associated with treatment outcomes and consensus interferon with or without ribavirin use such as dosing, length of treatment and other practice variations."

Gastroenterology, Department of Veterans Affairs Medical Center, San Francisco, CA, USA; University of California, San Francisco, CA, USA; Pharmacy Benefits Management Strategic Healthcare Group, Hines, IL, USA.

11/13/07

Reference
HS Yee, K Tortorice, S Chapman, and others. Hepatitis C Virus (HCV) Treatment Outcomes with Consensus Interferon with or without Ribavirin in Peginterferon/Ribavirin Non-responders/ Relapsers: Results from National Clinical Practice Settings. 58th Annual Meeting of the American Association for the Study of Liver Diseases (AASLD 2007). Boston, MA. November 2-6, 2007. Abstract 355.