Effects of interferon-α in patients with aids-associated Kaposi's sarcoma are related to blood interferon levels and dose

Definition of improved therapeutic regimens of interferon-α (IFN-α) for the treatment of Kaposi's sarcoma (KS) would be useful since currently recommended doses are sometimes associated with unacceptable toxicity. IFN concentrations were measured in serum samples from men with AIDS-associated KS who were enrolled in a trial of IFN-α alone (16 patients) or a trial of IFN-α combined with zidovudine (25 patients). Analyses were done to examine the relationship between the dose of IFN-α, blood level of IFN, and the patient's clinical response to treatment. There was no correlation between dose of zidovudine given and response. As expected, there was a high correlation between dose of IFN-α and blood level in both studies (p < 0.001). Furthermore, we found relationships between clinical response and both dose of IFN-α and blood level achieved. In the two studies combined, among men with >200 CD4 + cells/mm 3 of blood at baseline on average daily doses of >10 million international units (MIU) of IFN-α, 13 19 (68%) responded compared to 6 17 (35%) on