Pilot study of low-dose interleukin-2, pegylated interferon-α2b, and ribavirin for the treatment of hepatitis C virus infection in patients with HIV infection

Background. Patients infected with hepatitis C virus (HCV) and human immunodeficiency virus have a diminished HCV virologic response to standard interferon (IFN)-based therapies. We explored the strategy of initial immunostimulatory therapy with interleukin (IL)-2, followed by the addition of specific anti-HCV therapy, as a possible synergistic approach to treatment. Methods. Coinfected subjects (n = 23) with CD4 cell counts 1300 cells/muL received low-dose IL-2 daily for 12 weeks, followed by pegylated IFN-alpha2b and ribavirin for an additional 48 weeks. The primary end point was permanent discontinuation of treatment before week 24 due to toxicity or intolerance. Results. Six subjects (26.1%) discontinued treatment before week 24, and 11 (47.8%) discontinued treatment before week 60. Overall, 4 subjects discontinued because of adverse events. Four of 23 (17%; 95% confidence interval [CI], 5%-39%) had sustained virologic responses. Of 17 subjects with increased levels of alanine aminotransferase at baseline, 13 had follow-up measurements at week 60, of which 6 (46%) were normal. Conclusions. Low-dose IL-2 plus PEG-IFN and ribavirin was associated with a high discontinuation rate. Although the study was not powered for efficacy, CIs surrounding the treatment response rate suggest that this strategy should not be pursued in larger trials.