The U.S. Food and Drug Administration today approved Lumoxiti (moxetumomab pasudotox-tdfk) injection for intravenous use for the treatment of adult patients with relapsed or refractory hairy cell leukemia (HCL) who have received at least two prior systemic therapies, including treatment with a purine nucleoside analog. Lumoxiti is a CD22-directed cytotoxin and is the first of this type of treatment for patients with HCL.