Purpose: To define the safety and toxicity of interleukin-4 (IL-4) whe
n administered subcutaneously in patients with AIDS-related Kaposi's s
arcoma (AIDS-KS); to evaluate the effect of IL-4 on immunologic and vi
rologic parameters; and to preliminarily assess the response rate of I
L-4 in AIDS-KS. Patients and methods: Eighteen patients with mucocutan
eous, non-visceral AIDS-KS were treated with IL-4 at a dose of 1 mcg/k
g subcutaneously, daily until unacceptable toxicity or for a maximum p
eriod of six months. Twelve (66%) patients had extensive mucocutaneous
disease with over 25 lesions. Ten patients had received prior systemi
c chemotherapy. Seventeen had CD4+ lymphocyte counts less than 200/mm(
3). Results: 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/mm(3)) in 33%, mild a
nemia in 22%. Transient elevation of liver enzymes was noted in 17%. A
transient elevation in CD4+ lymphocyte counts occurred during the fir
st two weeks of therapy. Four of eleven patients tested showed marked
decline in plasma HIV RNA after four weeks. Partial remission was obse
rved in one patient, lasting six months. Three other patients (17%) ha
d stable disease: 7 weeks in one patient, and 10 weeks in each of the
two other patients. Conclusion. Grade 4 neutropenia (absolute neutroph
il count < 500/mm(3)) was the most common hematologic adverse effect w
ith IL-4 in patients with AIDS-KS. In contrast to in vitro findings, t
here 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 ly
mphocyte counts over 200/mm(3). Further studies of IL-4 in AIDS-KS may
be considered in patients with better immune status.