Inotuzumab ozogamicin versus FLAG-Ida in the treatment of relapsed or refractory B-cell acute lymphoblastic leukemia - real-world resource use data In June 2017, Inotuzumab ozogamicin (IO), a humanized anti-CD22 monoclonal antibody conjugated to a cytotoxic antibiotic agent calicheamicin [[1]], was approved by the European Medicines Agency (EMA) for treating adults with Philadelphia chromosome positive and negative relapsed or refractory CD22-positive B-cell acute lymphoblastic leukemia (ALL). Patient characteristics, including disease status at the time of treatment, number of previous lines of therapy and number of IO or FLAG-Ida cycles received were recorded. The IO group had also received more prior lines of therapy than the FLAG-Ida group, with 7 of 17 (41%) being on their third or fourth line of therapy whereas no FLAG-Ida recipient had received more than two prior lines of therapy, but these differences were not statistically significant. [Extracted from the article]