Beta-interferon therapy in patients with poor-prognosis Kaposi sarcoma related to the acquired immunodeficiency syndrome (AIDS)

Interferons are factors produced by cells of the immune system that are involved in the stimulation and development of an immune response. A 20 to 40 percent response rate has been reported with alpha-interferon therapy in patients with Kaposi's sarcoma, a malignant disease that is related to early-stage acquired immunodeficiency syndrome (AIDS). Patients with Kaposi's sarcoma who were treated with alpha-interferon had lower levels of infection, and some activity against human immunodeficiency virus (HIV, which causes AIDS) has been shown. However, alpha-interferon can only be given at certain doses because the drug can be toxic to blood cells and cause liver complications. Blood cell toxicity has also been noted with the drug zidovudine, which is used to treat AIDS. When alpha-interferon and zidovudine are used together in a combined therapy, the maximum dose that can be used to prevent toxicity is one half of the dose of each drug when it is used alone. However, beta-interferon, which has many of the same immunological effects as alpha-interferon, including antiviral activity, can be used at higher doses before toxicity develops. The efficacy of high doses of beta-interferon was examined in 38 patients with AIDS-related Kaposi's sarcoma. The majority of the patients, however, were in the later stages of AIDS and had clinical or laboratory conditions which predicted a poor response to interferon treatment. AIDS and Kaposi's sarcoma remained stable in 40 percent of the patients for more than 26 weeks. However, only 16 percent of the patients showed a favorable response to the beta-interferon treatment. Some antiviral activity was seen with the use of beta-interferon, and there was a decrease in the number of infections that would be expected in a similar group of patients. Minimal toxicity was primarily localized to the skin. Therefore, the response of patients with Kaposi's sarcoma to beta-interferon, as with alpha-interferon, is minimal at advanced stages of AIDS. (Consumer Summary produced by Reliance Medical Information, Inc.)