Immunotoxin therapy for hematologic malignancies: where are we heading?

•The review describes recent advances in immunotoxin therapy in leukemias.•The review focuses overview of immunotoxins classified by target surface molecule.•The review centers more on immunotoxins related to clinical trials. The identification of numerous unique targets in recent years has led to the development of various immunotoxins (ITs) for treating hematological malignancies. Some of these ITs have advanced to clinical trials and have resulted in a high response rate against leukemia. Newer targets with improve specificity are also being identified for targeting several leukemias. Currently, several modified versions of ITs with increased efficacy are being constructed and evaluated for cytotoxicity in vitro as well as in vivo. Here, we summarize recent advances in preclinical and clinical studies of recombinant ITs targeting diverse surface receptors.