The dose-response relationship of peginterferon alfa-2a and ribavirin in the treatment of patients coinfected with HIV-HCV.

PURPOSE: The relationship between peginterferon/ribavirin exposure and the probability of achieving a sustained virologic response (SVR) in HIV-HCV coinfected patients is not well described. We conducted a retrospective analysis of HIV-HCV coinfected patients randomized to 48 weeks of treatment with peginterferon alfa-2a (40 kD) 180 µg/week and ribavirin 800 mg/day in the multinational APRICOT study to define optimal exposure thresholds. METHOD: Actual drug exposure was estimated in 287 patients, taking into consideration dose reductions for adverse events or laboratory abnormalities. RESULTS: SVR overall and SVR in those completing treatment was, respectively, 29% and 37% among HCV genotype-1 patients and 59% and 68% among genotype non-1 patients. No patients with ≤40% exposure to ribavirin achieved an SVR. Receiver operating characteristic analysis identified that threshold exposures to both drugs of >75% (genotype-1) and >60% (genotype non-1) are associated with SVR. An existing generalized additive model populated with data from HCV monoinfected patients was updated to predict an overall SVR of 37% if genotype-1 patients received ribavirin 1000 or 1200 mg/day but at the cost of a higher incidence of anemia (23%). CONCLUSION: Completion of scheduled treatment and exceeding certain thresholds for exposure to peginterferon alfa 2a (40 kD) and ribavirin is associated with higher SVR rates.

Eligibility for and outcome of hepatitis C treatment of HIV-coinfected individuals in clinical practice: the Swiss HIV cohort study.

BACKGROUND: Morbidity and mortality of individuals co-infected with HIV and hepatitis C virus (HCV) is often determined by the course of their HCV infection. Only a selected proportion of those in need of HCV treatment are studied in randomized controlled trials (RCTs). We analysed the prevalence of HCV infection in a large cohort, the number of individuals requiring treatment, the eligibility for HCV treatment, and the outcome of the combination therapy with pegylated interferon-a and ribavirin in routine practice. METHODS: We analysed prescription patterns of HCV treatment and treatment outcomes among participants from the Swiss HIV Cohort Study with detectable hepatitis C viraemia (between January 2001 and October 2004). Efficacy was measured by the number of patients with undetectable HCV RNA at the end of therapy (EOTR) and at 6 months after treatment termination (SVR). Intention-to-continue-treatment principles were used. RESULTS: A total of 2150 of 7048 (30.5%) participants were coinfected with HCV; HCV RNA was detected in 60%, and not assessed in 26% of HCV-antibody-positive individuals. One hundred and sixty (12.5%) of HCV-RNA-positive patients started treatment. In patients infected with HCV genotypes 1/4 or 2/3, EOTR was achieved in 43.3% and 81.2% of patients, respectively, and SVR rates were 28.4% and 51.8%, respectively. More than 50% of the HCV-treated patients would have been excluded from two large published RCTs due to demographic, clinical and laboratory criteria. CONCLUSIONS: Despite clinical and psychosocial obstacles encountered in clinical practice, HCV treatment in HIV-coinfected individuals is feasible with results similar to those obtained in RCTs.

Effect of baseline CD4 cell count on the efficacy and safety of peginterferon Alfa-2a (40KD) plus ribavirin in patients with HIV/hepatitis C virus coinfection.

OBJECTIVE: The impact of baseline CD4 status on hepatitis C virus (HCV) treatment response among patients with HIV/HCV coinfection was investigated using data from a randomized study of peginterferon alfa-2a (40KD) + ribavirin (Peg-IFN/RBV). METHODS: Of 860 patients treated with conventional interferon alfa-2a + ribavirin (IFN/RBV), peginterferon alfa-2a (40KD) + placebo (Peg-IFN), or Peg-IFN/RBV for 48 weeks, 857 patients had baseline CD4 data available and were included in the analysis. Efficacy and safety were analyzed according to baseline CD4 status as absolute cell count and proportion of total lymphocytes. RESULTS: Sustained virologic response (SVR) rates were highest with Peg-IFN/RBV across all CD4 strata. With Peg-IFN/RBV, SVR rates were independent of baseline CD4 in genotype 2/3 patients, but in genotype 1 patients, they tended to be higher with higher CD4 or CD4%. Frequencies of adverse events (AEs) and serious AEs were similar among treatment arms and CD4 strata. Withdrawal and dose reduction rates attributable to safety were highest with CD4 <200 cells/muL. CONCLUSIONS: Peg-IFN/RBV could be effective and well tolerated in HIV/HCV-coinfected individuals with stable HIV. With Peg-IFN/RBV, response tended to increase with higher CD4 counts in genotype 1; however, because of the paucity of patients with CD4 <200 cells/muL, these data require corroboration.