Use of granulocyte macrophage colony stimulating factor alone or in combination with interferon-alpha-2b for treatment of chronic hepatitis C.

Background/aims: We have evaluated the effect of granulocyte macrophage colony-stimulating factor (GM-CSF) when utilized either alone or in combination with interferon for treatment of chronic hepatitis C virus (HCV).

Methods: A total of 71 patients with chronic HCV, elevated alanine aminotransferase and normal hepatic function were enrolled into these studies. Nineteen patients who had previously failed to achieve both biochemical and virologic response during interferon therapy were treated with increasing doses of GM-CSF alone (65-250 microg/m2 three times weekly) for 6 months. Another 52 patients who had not been previously treated with interferon entered a randomized controlled trial; 25 were treated with interferon alone (3 mU three times weekly) and 27 with a combination of interferon+GM-CSF (3 mU+250 microg/m2 three times weekly). All patients were treated for 6 months. Both groups were well matched for age, sex, race, serum alanine aminotransferase, HCV-RNA titer, liver histology score and cirrhosis.

Results: None of the patients treated with GM-CSF alone developed either biochemical or virologic response at any of the treatment dosages and mean HCV-RNA titer remained unchanged from baseline during this therapy. For patients in the randomized controlled trial, biochemical and virologic responses were observed in 54% of interferon-treated patients compared to 31.8% for those treated with interferon+GM-CSF. Long-term sustained virologic response was observed in only one patient in each group. No significant differences were observed in HCV-RNA titer during the course of treatment. GM-CSF treatment was associated with a significant increase in total white blood cell count and absolute eosinophil count, which peaked within the first month of therapy and declined spontaneously during the remaining 5 months.

Conclusion: GM-CSF either alone or in combination with interferon does not appear to be effective for treatment of chronic HCV.