Beschreibung:
<jats:p><jats:bold>A<jats:sc>bstract</jats:sc>: </jats:bold> The interleukin (IL)‐2 receptor has proved an attractive target for T cell‐directed therapies. Agents including monoclonal antibodies, single‐chain antibody immunoconjugates, radioimmunoconjugates, and, most recently, ligand fusion toxins have demonstrated activity <jats:italic>in vitro</jats:italic> and in clinical trials in both hematologic malignancies and diseases characterized by proliferation of activated T cells, such as graft‐versus‐host disease. DAB<jats:sub>389</jats:sub>IL‐2 (ONTAK) is a ligand fusion toxin consisting of the full‐length sequence of the IL‐2 gene genetically fused to the enzymatically active and translocating domains of diphtheria toxin. DAB<jats:sub>389</jats:sub>IL‐2 and its predecessor, DAB<jats:sub>486</jats:sub>IL‐2, have demonstrated activity in a variety of diseases, including cutaneous T cell lymphoma (CTCL), psoriasis, rheumatoid arthritis, and HIV infection. Further clinical development of IL‐2 fusion toxins in CTCL and other hematopoietic malignancies is predicated on identification of the high‐affinity IL‐2 receptor complex on the malignant cells and on a better understanding of the biological determinants of cytotoxicity of these molecules <jats:italic>in vivo</jats:italic>.</jats:p>