IL-3 in the clinic

Since the cloning of human interleukin 3 (IL-3) in 1986 [1] and the demonstration of its proliferative effects on multiple hematopoietic progenitor cells, IL-3 has been widely studied to treat different states of bone marrow failure or hematologic malignancies, to mobilize or expand hematopoietic progenitor cells for transplantation, and to support engraftment after bone marrow transplantation. However, no condition for the clinical use of IL-3 has been established so far despite its theoretical advantages as an early-acting cytokine and in contrast to erythropoietin (EPO), G-CSF, or GM-CSF all of which have already been approved for several clinical modalities, Here we shortly review our current knowledge about the effects of IL-3 on the molecular and cellular level, summarize recent clinical studies with IL-3, and discuss further perspectives for use of this cytokine.