IFN-B has demonstrated a dose-dependent ability to suppress the replication of HIV in the test tube. In addition, previous studies have shown AZT to be an effective inhibitor of HIV reverse transcriptase; Phase I and II study benefits of AZT treatment include increased objective clinical improvement, decreased mortality rate, and decreased incidence of opportunistic infections. Long-term AZT use, however, presents possible limitations secondary to intolerance. This study, therefore, will investigate the potential antiviral activities of a combination of IFN-B and AZT to determine the safety and efficacy of such treatment in patients with AIDS related Kaposi's sarcoma. It is believed that combination drug therapy consisting of low doses of each drug will reduce the potential of toxicity, treatment failures, and disease recurrences resulting from drug-resistant virus mutants.

Patients undergo evaluations to determine the extent of their disease and the status of their immune system. Patients then receive IFN-B subcutaneously once a day at one of three different dose levels. Patients also take AZT at 1 of 2 doses. The first 12 patients are treated with the lower dose of AZT. The first 4 patients are entered at level 1 of IFN-B. If no dose-limiting toxicity is seen in these 4 patients after 2 weeks of therapy, 4 patients are then enrolled at level 2 of IFN-B. The study proceeds in this manner until the highest tolerated dose or level 3 is reached. If both drugs are tolerated, patients then remain on both medications as long as they continue to tolerate the medications and show some improvement in either antiviral response, immune response, or clinical response for as long as 24 weeks. The initial three doses of IFN-B are given to each patient at the study site during which time the patient is trained to self-administer the IFN-B. Patients are then seen weekly for 4 months and every 2 weeks thereafter.