Virologic and immunologic activity of PegIntron in HIV disease.

Objective: The primary objectives of this study were to evaluate the safety, tolerability, and antiviral activity of pegylated interferon-α (Peglntron) in HIV-1 treatment-experienced patients failing their current antiretroviral regimen. Design: This was a phase II, multicenter, randomized, double-blind, placebo-controlled study. Methods: Patients were randomized to receive either weekly subcutaneous Peglntron 0.5, 1.0, 1.5, or 3 μg/kg or placebo added to their failing antiretroviral regimen for the first 4 weeks of study. Individuals who achieved more than 0.5 log 10 reduction in HIV RNA at week 4 were allowed to continue study medication with optimization of their antiretroviral therapy for an additional 24 weeks. Results: In the 259 patients included in the intent-to-treat analysis, changes in plasma HIV RNA from baseline to week 4 were -0.25 (P>0.5), -0.46 (P=0.024), ―0.39 (P= 0.008), ―0.53 (P 0.5) log 10 copies/ml in the 0.5, 1.0, 1.5, and 3.0 μg/kg and placebo arms, respectively. No significant changes were seen in CD4 T-cell parameters in any of the treatment or control arms. Adverse events (most commonly fever, flu-like symptoms, other constitutional symptoms, and psychiatric symptoms) resulted in discontinuation of study medication in 13, 17, 16, 28, and 2% of patients in the 0.5, 1.0, 1.5, 3.0 μg/kg, and placebo group, respectively. Conclusion: The demonstration of significant antiviral activity in a heavily pretreated patient population with acceptable toxicity and only weekly dosing makes PegIntron a potentially valuable therapy for patients with HIV infection that warrants further investigation in a broader population of patients.