Comparison among Different Types, Dosages and Duration of Interferon Therapy in Chronic Hepatitis C

In an attempt to determine the best therapeutic protocol for the treatment of chronic hepatitis C with interferon (IFN), we reported our experience comparing the efficacy of IFN at the usual dose and duration, i.e. 3 million units (MU) three times weekly for 6 months, with the immediate and long-term effects of different types, dosages and duration of IFN therapy. 300 patients with chronic hepatitis C were randomly assigned to five groups of 60 subjects each and treated as follows: group A - recombinant IFN alpha (rIFNalpha) 3MU three times weekly for 6 months; group B - rIFNalpha 6MU three times weekly for 6 months; group C - rIFNalpha 3MU 3 times weekly for 12 months; group D - lymphoblastoid IFN (L-IFN) 6MU three times weekly for 6 months; group E - L-IFN 3MU three times weekly for 12 months. The diagnosis of hepatitis was based on clinical, serological and histological data in all patients. A 'biochemical response' was defined as the normalisation of alanine aminotransferase (ALT) values, and a 'complete response' as the normalisation of ALT with disappearance of serum hepatitis C virus (HCV)-RNA. A 'sustained response' was defined as the persistence of ALT normalisation and undetectable viraemia 2 years after the end of treatment. The five groups were homogeneous. The incidence of dropouts was 8%, and IFN treatment was interrupted for adverse effects in 11% of the patients. In group A, 55% of the patients showed a 'biochemical response' and 31% of the subjects demonstrated a 'complete response'. In group B, a 'biochemical response' was observed in 61% and a 'complete response' in 36% of the cases. In group C, 77% of the subjects showed a 'biochemical response', with a 'complete response' seen in 40%. In group D, we observed a 'biochemical response' in 55% of the patients and a 'complete response' in 33%. In group E, 79% of the subjects had a 'biochemical response', and a 'complete response' was seen in 38%. At the end of the treatment-free follow-up the percentage of patients with a sustained response was 24% in group A, 28% in group B, 35% in group C, 27% in group D and 33% in group E. Therefore, a longer period of IFN treatment seems to provide higher percentages of sustained response than the usual 6-month duration, independently of the type of IFN. Moreover, the patients treated with a higher dosage (6MU 3 times weekly) for 6 months showed a slightly better sustained response rate compared with the usual dose. In conclusion, even if the differences among the response rates in the five groups were not statistically significant, we recommend a 12-month regimen, possibly using higher dosages at least in the first 4 to 6 months of treatment.