Personalized therapy for chronic viral hepatitis C in the naive patient: How can we optimize treatment duration as a function of viral genotype?

Pegylated interferon plus ribavirin is the standard treatment for chronic hepatitis C (CHC). It yields sustained virological response (SVR) rates of 42-52% for genotype 1, 66-72% for genotype 4, and 76-80% for genotypes 2 and 3. Hence, the patient's genotype appears to be a determining predictive factor for the SVR. We have reviewed the literature in order to determine whether a genotype-specific treatment duration should be envisaged. The largest study to date of patients infected with HCV genotype 2 or 3 confirmed the value of the standard treatment duration of 24 weeks. Shorter treatments exposed the patients to a greater risk of relapse. For genotype 1, it was possible to offer a shorter, 24-week course of treatment to the 35% of patients with an initial viral load below 600,000 IU/mL and an early virological response (EVR) at week 4 (negative PCR), resulting in an SVR of 89%. For the remaining two-thirds of genotype 1 patients with a high viral load, the treatment duration should remain at 48 weeks. A subgroup of patients - the "slow virological responders" (positive PCR at week 12 but with less than 6000 IU/mL; negative PCR at week 24) - benefited from the extension of the treatment to 72 weeks, with an SVR of 88%. For patients infected with genotype 4 virus, combination therapy should feature a ribavirin dose of more than 1000 mg/day for an optimal duration of 48 weeks.