Interleukin-4 in the treatment of AIDS-related Kaposi's sarcoma

To define the safety and toxicity of interleukin-4 (IL-4) when administered subcutaneously in patients with AIDS-related Kaposi's sarcoma (AIDS-KS); to evaluate the effect of IL-4 on immunologic and virologic parameters; and to preliminarily assess the response rate of IL-4 in AIDS-KS.

Eighteen patients with mucocutaneous, non-visceral AIDS-KS were treated with IL-4 at a dose of 1 mcg/kg subcutaneously, daily until unacceptable toxicity or for a maximum period of six months. Twelve (66%) patients had extensive mucocutaneous disease with over 25 lesions. Ten patients had received prior systemic chemotherapy. Seventeen had CD4+ lymphocyte counts less than 200/mm3.

The most common adverse effects included headache in 78%, fever in 56%, chills in 44%, and edema in 44%. Hematologic toxicities consisted of grade 4 neutropenia (less than 500/mm3) in 33%, mild anemia in 22%. Transient elevation of liver enzymes was noted in 17%. A transient elevation in CD4+ lymphocyte counts occurred during the first two weeks of therapy. Four of eleven patients tested showed marked decline in plasma HIV RNA after four weeks. Partial remission was observed in one patient, lasting six months. Three other patients (17%) had stable disease: 7 weeks in one patient, and 10 weeks in each of the two other patients.

Grade 4 neutropenia (absolute neutrophil count < 500/mm3) was the most common hematologic adverse effect with IL-4 in patients with AIDS-KS. In contrast to in vitro findings, there was a decrease in plasma HIV RNA after four weeks of IL-4 therapy in the majority of patients tested. IL-4 produced minimal anti-tumor effects in AIDS-KS with one partial remission in a patient with CD4 lymphocyte counts over 200/mm3. Further studies of IL-4 in AIDS-KS may be considered in patients with better immune status.