CD22 and acute lymphoblastic leukemia: Moxetumomab pasudotox (Lumoxiti®, AstraZeneca, Cambridge, England, UK) is a recombinant anti-CD22 immunotoxin that has been recently evaluated in pediatric patients with r/r B-ALL and a respective phase I study has reported severe neutropenia in 17% and febrile neutropenia in 16% of treated patients [79].