The Dose-Response Relationship of Peginterferon Alfa-2a and Ribavirin in the Treatment of Patients Coinfected with HIV-HCV

Center of Internal Medicine, Hirslanden Clinic Aarau, Aarau, Switzerland.
HIV Clinical Trials (Impact Factor: 2.14). 01/2012; 13(1):33-45. DOI: 10.1310/hct1301-033
Source: PubMed

ABSTRACT 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.
Actual drug exposure was estimated in 287 patients, taking into consideration dose reductions for adverse events or laboratory abnormalities.
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%).
Completion of scheduled treatment and exceeding certain thresholds for exposure to peginterferon alfa 2a (40 kD) and ribavirin is associated with higher SVR rates.

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