Efficacy of natural BALL-1 interferon-α treatment for patients with chronic hepatitis C and a possible enhancing effect of a twice-daily starting regimen with interferon-β

Background/Aims: Two distinct natural interferon-α (BALL-1 and Namalwa) are available for patients with chronic hepatitis C in Japan, but the efficacy has not been well documented. We investigated two studies using a natural BALL-1 interferon-α treatment for chronic hepatitis C and assessed its efficacy. Methodology: In interferon-α monotherapy (Study I), 42 patients with chronic hepatitis C received 10 mega units of BALL-1 interferon-α intramuscularly consecutively for an initial 2 weeks followed by three times a week for 6 months totally. In a combination therapy of natural interferon-α and interferon-β (Study II), 24 patients received intravenous 3 mega units of interferon-α twice daily for the initial 2 weeks followed by 10 mega units of natural BALL-1 interferon-α consecutively for 2 weeks and three times a week for 6 months totally. Efficacy and predictive factors for sustained viral response was investigated. Results: Study II included significant younger patients than study I. Sustained virological response was obtained in 31.0% in Study I and 56.5% in Study II by intention-to-treat analysis. Sustained viral response in the group of genotype 1b and viral load more than 100 KIU/mL was 3/23 (13.0%) and 8/18 (44.4%) in Study I and II, respectively. The response rate in Study II was higher than that of Study I especially among the patients with high pretreatment viral load or genotype 1b (p<0.05). Multivariate analysis showed that pre-treatment HCV-RNA levels, HCV-genotype, and histological staging before the interferon treatment were significant predictive factors of sustained viral response. Conclusions: These studies suggest that natural BALL-1 interferon-α is useful for inducing sustained viral response in patients with chronic hepatitis C, even in those possessing genotype 1b and high viral load. In addition, the combination therapy with a starting regimen with twice-daily interferon-β administration for 2 weeks may be more effective than monotherapy.