A Phase II Study of Recombinant Human Interferon-α_2a and Zidovudine in Patients with AIDS-Related Kaposi's Sarcoma

To assess safety, antitumor response, and immunological and virological activity of interferon-α_2a and zidovudine combination therapy in patients with AIDS-related Kaposi's sarcoma, we conducted an open-label, Phase II, multicenter study. Sixty-three patients with biopsy-proven Kaposi's sarcoma and no previous interferon-α therapy received zidovudine 600 mg/day and interferon-α_2a 18 × 10⁶ U/day. The median duration of follow-up was 49 weeks. Of 62 evaluable patients, 25 (40%; 95% confidence interval, 0.28-0.52) showed a complete (26%) or partial (15%) antitumor response. Eight of 30 patients (27%) with <100 CD4 cells/mm³ and 17 of 32 patients (53%) with ≥100 CD4 cells/mm³ had a response. The median time to response was 36 weeks. Of the 25 patients with a response, four developed tumor progression. The median duration of response was 22.4 weeks. Eight patients (13%) developed another AIDS-defining event and 13 (21%) died. The major toxicities included anemia (16%), neutropenia (27%), elevated serum transaminases (16%), weight loss (16%), malaise (14%), fatigue (14%), fever (10%), and headache (6%). Therapy with intermediate-dose interferon-α_2a and zidovudine resulted in tumor regression in patients with AIDS-related Kaposi's sarcoma who had a wide range of CD4 cell counts; this therapy was relatively well tolerated.