CD22 and acute lymphoblastic leukemia: In 2017, blinatumomab (bispecific anti-CD3/CD19 monoclonal antibody) and inotuzumab ozogamicin (InO; calicheamicin-based antibody–drug conjugate targeting CD22) received full approval from the Food and Drug Administration for R/R precursor B-ALL (Ph+ and Ph−) in adults based on promising results from phase II and phase III clinical trials (37–42).