Hepatitis C virus genotype 4 therapy: progress and challenges.

The hepatitis C virus genotype 4 (HCV-4) is prevalent in Egypt, the Middle East and Africa. Recently, the epidemiology of HCV-4 has changed and this genotype has begun to cross borders and spread to several regions in Europe through immigration and injection drug use. HCV-4 has been considered a difficult-to-treat genotype based on the low sustained virological response (SVR) rates obtained with conventional interferon (IFN)-based regimens. Pegylated interferons (PEG-IFN) plus ribavirin therapy for chronic HCV-4 has been associated with increased SVR rates of more than 60%. Shorter treatment of chronic HCV-4 patients with rapid and early virological responses has been associated with high SVR rates, better compliance, fewer adverse events and lower costs. Despite this progress, the treatment of HCV-4 non-responders, injection drug users, patients coinfected with human immunodeficiency virus, thalassaemic patients, patients on haemodialysis and patients with HCV-4 recurrence after liver transplantation still represents a significant therapeutic challenge. Treatment of HCV-4 has markedly improved, with higher sustained response rates and the possibility of shorter regimens. Despite the recent progress in the treatment of HCV-4, more research is required to optimize current therapy and include genotype 4 patients in clinical trials on emerging therapies such as specifically targeted antiviral therapy for HCV with protease and/or polymerase inhibitors.