Lower-than-standard dose peg-IFN alfa-2a for chronic hepatitis C caused by genotype 2 and 3 is sufficient when given in combination with weight-based ribavirin.

Mono-therapy with pegylated interferon (peg-IFN) has shown that a lower-than-standard dose yields the same sustained viral response (SVR) rates as standard doses for chronic hepatitis C virus (HCV) infection caused by genotypes 2 or 3. Our aim was to see if a fixed, lower-than-standard dose of peg-IFN alfa-2a (135 microg weekly) in combination with ribavirin 11 mg/kg daily for 24 weeks yields sufficient SVR rates for genotypes 2 or 3. Hundred consecutive patients with a mean age of 44 years (range 20-69 years), 59 with genotype 3 and 41 with genotype 2, were studied. Rapid viral response (RVR) with HCV-RNA <15 IU/mL at treatment week 4 and SVR were calculated. RVR was achieved by 28/40 (70%) patients with genotype 2 and 41/58 (71%) with genotype 3. Significantly more genotype 2 patients with RVR achieved SVR 27/28 (96%) than genotype 2 patients who failed to achieve RVR, 8/12 (66%), P = 0.009. The corresponding figures for genotype 3 patients were 39/41 (95%) vs 11/17 (65%), respectively, P = 0.002. In total, SVR was achieved by 35/41 (85%) patients with genotype 2 and 51/59 (86%) patients with genotype 3, respectively. We found that 135 microg peg-IFN alfa-2a weekly was sufficient for treatment of genotype 2 and 3 chronic hepatitis C when combined with RBV dosed daily according to body weight. This combination yielded high SVR rates (85-86%) and may be cost-saving.