Phase I Trial with the Interferon Inducer Poly I:C/Poly-L-Lysine (Poly ICL)

Abstract

Poly I:C/poly-L-lysine (poly ICL) was previously shown to be a potent inducer of interferon (IFN) production in nonhuman primates. In this limited trial in five patients with advanced cancer, poly ICL stimulated primarily leukocyte interferon (IFN-α) with peak titers of 40 to 160 units/ml, usually at 24 hours after poly ICL administration. Treatments were regularly followed by fever, usually maximum at 5-7 after drug administration. Other side effects included chills, fatigue, malaise, and headache. Hypotension did not occur. One patient experienced bronchospasm and another developed urticaria immediately following poly ICL injection. These two patients and a third patient (who did not experience any allergic reactions) were found to have developed serum antibodies reactive with poly ICL. In addition, two patients treated with poly ICL using carbomethylcellulose (CMC) as a solubilzing agent (poly ICLC) without allergic reactions in a previous study were also found to have such antibodies. The relationship between apparent allergic reactions and the observed antibody responses remains uncertain. There were no clear therapeutic responses observed.