CD22 and acute lymphoblastic leukemia: In 2017, Inotuzumab ozogamicin (InO) gained FDA approval for treatment of relapsed or refractory CD22+ acute lymphoblastic leukaemia (ALL), based on phase III clinical trial INO-VATE ALL, that showed significant improvement in mPFS (5.0 vs. 1.8 months, HR 0.45, 95% CI 0.34–0.61; p < 0.001) and mOS (7.7 vs. 6.7 months, HR 0.77, 95% CI 0.58–1.03, p = 0.04) with InO as compared to investigator’s choice standard intensive chemotherapy [37].