Moxetumomab pasudotox connects anti-CD22 to PE38, a fragment of Pseudomonas exotoxin A, and induces apoptosis through the inhibition of protein synthesis.62,63 A phase 1 study (NCT00462189) demonstrated an ORR of 86% in hairy cell leukemia (HCL) patients with no dose-limiting toxicity.64 Moreover, a pivotal phase 3 study (NCT01829711) for relapsed or refractory HCL obtained an ORR of 75%, with a CR rate of 41%.65 The FDA approved moxetumomab pasudotox (Lumoxiti) for the treatment of adult patients with relapsed or refractory HCL. The gene discussed is CD22; the disease is hairy cell leukemia.