Overview of interleukin‐2 as an immunotherapeutic agent

Abstract Interleukin‐2 (IL‐2) is a lymphokine which has a variety of in vivo immunomodulatory effects. The administration of IL‐2 can mediate enhancement of cellular immune responses, induction of lymphocyte proliferation, production of cytokines, and regression of established tumor in animal models. The availability of large quantities of recombinant IL‐2 has enabled investigators to examine its therapeutic potential in the treatment of human cancer. Several studies have documented the ability of IL‐2 administration to cause durable tumor regression in patients with advanced melanoma and renal cell cancer. Toxicity of therapy is dose related and is mediated by a vascular capillary leak syndrome, lymphocytic infiltration, and the release of cytokines secreted in response to IL‐2 administration. The side effects are completely reversible upon cessation of therapy. Future efforts are aimed at increasing the antitumor efficacy and decreasing the toxicity of IL‐2 administration.