Old rivals become new friends

In this issue of Blood, Jabbour et al report on the use of inotuzumab ozogamicin (InO) in the setting of measurable residual disease (MRD) in patients with B-cell acute lymphoblastic leukemia (ALL).1 InO (Besponsa) is an antibody-drug conjugate approved for the treatment of relapsed/refractory B-cell ALL (R/R B -ALL) in adults.2 InO consists of a CD22-targeting immunoglobulin G4 humanized monoclonal antibody conjugated to calicheamicin, similar to the anti-CD33 antibody-drug conjugate gemtuzumab ozogamicin (GO, Mylotarg).