CD22 and acute lymphoblastic leukemia: Preclinical studies showed that calicheamicin conjugated to an anti-CD22 antibody resulted in potent cytotoxicity leading to regression of B-cell lymphoma and prevention of xenograft establishment at picomolar concentrations.86 Phase 1 studies in non-hodgkin lymphoma (NHL) established a maximum tolerated dose of 1.8 mg/m2 InO given intravenously every 3 to 4 weeks.87 Subsequently, InO was studied in adults with relapsed/refractory ALL.88 In this phase 2 trial, 90 patients were treated with either a single infusion every 3 to 4 weeks or weekly InO infusions.