Background:  Relapses after successful anti-hepatitis C virus (HCV) treatment considerably reduce sustained virological response rates. The effect of extended therapy to diminish HCV relapses in HIV-co-infected patients is unknown.

Methods:  PRESCO was a multi-center, prospective trial conducted in Spain that evaluated the efficacy and safety of pegylated interferon-alpha2a (pegIFN-a2a) 180 µg/week plus ribavirin (RBV) 1000 to 1200 mg/day as treatment of chronic hepatitis C in HIV⁺ subjects. Only patients achieving >2 log drop in HCV RNA at week 12 were allowed to continue on therapy. It lasted for 6 or 12 months in HCV genotypes 2 and 3, and 12 or 18 months in HCV-1 and -4.

Results:  A total of 389 patients were included in the trial, of whom 191 (49%) were infected by HCV-1, 152 (39%) by HCV-2/3, and 46 (12%) by HCV-4; 74% were on HAART, with 67% having HCV RNA ³500,000 IU/mL. Median  age was 40 and median CD4, 546 cells/mm³. In an intent-to-treat analysis, sustained virological response was achieved in 193 (49.6%):  HCV-1, 68 (35%); HCV-2/3, 110 (72%); and HCV-4, 15 (33%). A high drop-out rate (63%), mainly due to voluntary withdrawal, penalized the extended treatment arms; only 46 patients infected with HCV-2/3 and 9 with HCV-1 completed the planned extended course of therapy. In multivariate analysis, HCV RNA ³500,000 IU/mL (OR 4.54, 95%CI 1.45 to 14.22, p = 0.009) and detectable HCV RNA at week 4 (OR 2.86, 95%CI 1.21 to 6.76, p = 0.02) were identified as independent predictors of relapse. Extended treatment did not result in a lower relapse rate, regardless of HCV genotype (see the table). Among patients with detectable HCV RNA at weeks 4 or 12, relapses were comparable between shorter and extended treatment arms. 

Conclusions:  Higher baseline HCV RNA levels and detectable HCV RNA at week 4 of therapy were predictors of relapse following a course of pegIFN+RBV in HIV/HCV-co-infected patients. No benefit was seen with extended treatment durations, regardless of HCV genotype.