Background: We have shown that 12-14 weeks treatment is effective in HCV-2 or -3 patients with undetectable HCV-RNA after 4 weeks of therapy (rapid virologic response).
Patients: To identify predictors of sustained virologic response, rapid virologic response and relapse following short treatment, we pooled data from the original Italian and Norwegian studies. Four hundreds and three patients were treated with PegIFN alpha-2b (1.0, n=281 or 1.5 microg/kg, n=122) and ribavirin (800-1200 mg) for 12-14 or 24 weeks, depending on negative or positive HCV-RNA at week 4.
Results: Sustained virologic response differed between cases with and without rapid virologic response (85% versus 62%, P<0.0001), mild and severe fibrosis (83% versus 67%, P=0.004), and HCV-2 and -3 (81% versus 73%, P=0.05). In a regression model, RVR (odds ratio 3.49, confidence interval 1.73-5.36) and mild fibrosis (odds ratio 2.91, confidence interval 1.57-5.38) independently predicted sustained virologic response. Rapid virologic response was obtained in 274 (68%) patients, 163/242 (67%) HCV-2, and 111/161 (69%) HCV-3. Patients with RVR had more frequently mild fibrosis (70% versus 54%, P=0.03), and high PegIFN dose (78% versus 64%, P=0.005). In a regression model, mild fibrosis independently predicted rapid virologic response (odds ratio 1.87, confidence interval 1.10-3.16). In rapid virologic response patients, sustained virologic response was achieved in 85% of both HCV-2 and -3. Virologic relapse was observed in 10.6% rapid virologic response patients and was more frequent among those with low ALT (14% versus 2%, P=0.04).
Conclusion: In HCV-2 or -3, the HCV-RNA status after 4 weeks of therapy may guide treatment duration. HCV-2 and HCV-3 patients with severe fibrosis are less likely to experience both rapid virologic response and sustained virologic response, and more frequently relapse after a 12 or 14 weeks duration of antiviral therapy.