Hepatitis C virus genotype 5: prospective evaluation of peginterferon/ribavirin treatment efficacy and predictive value of on-treatment virological responses for sustained virological response.

ABSTRACT

GOALS To examine the treatment efficacy of a combination of pegylated interferon α (PegIFNa) plus ribavirin in patients chronically infected with hepatitis C virus genotype 5 (HCV-5) and to assess the on-treatment virological responses as predictors of sustained virological response (SVR). BACKGROUND: HCV-5 is uncommonly reported, and little therapeutic data is available regarding previous retrospective studies yielding contradictory results. STUDY In a prospective, open-label, single-center study, 27 treatment-naive HCV-5 patients, treated for 48 weeks with PegIFNa-2a/ribavirin, were evaluated. Rapid viral response (RVR), early viral response (EVR), 24-week viral response (24-wVR), end-of-treatment response (ETR), and SVR were assessed, defined as negative viral load at weeks 4, 12, 24, 48, and 72 after treatment initiation, respectively. RESULTS: Attainment of SVR was observed in 17 of the 27 (63%) patients. RVR, EVR, and 24-wVR occurred in 16 (59.3%), 25 (92.6%), and 24 (88.9%) patients, respectively. All but 1 patient achieving 24-wVR went on to achieve ETR (rate 85.2%), but 6 patients subsequently relapsed (relapse rate 26.1%). The positive/negative predictive values on SVR were 93.8%/81.8% for RVR, 68%/100% for EVR, and 66.7%/66.7% for 24-wVR. CONCLUSIONS: Patients with HCV-5 showed an overall good response to a 48-week combined antiviral treatment (SVR 63%). Albeit the ETR was high (85.2%), attainment of SVR remained affected by a substantial relapse rate, in our setting 26.1%. The predictive value of early viral dynamics on SVR merits adequate consideration in larger clinical trials targeting to optimize treatment for patients infected with HCV-5.