Inotuzumab Ozogamicin for Children With MRD Positive CD22+ Lymphoblastic Leukemia

This trial is a limited multi-center, Phase II study to evaluate inotuzumab ozogamicin (Besponsa) in pediatric patients with MRD positive CD22-positive B-lymphoblastic leukemia (B-ALL). Some patients with newly diagnosed ALL maintain low levels of MRD, despite achieving complete remission with less than 5% blasts in the bone marrow. Others experience re-emergence of low level MRD or increasing levels of MRD on therapy or post-transplant. New approaches are needed to achieve undetectable MRD in these high-risk patients. Inotuzumab ozogamicin is an antibody-drug conjugate composed of a humanized IgG subtype 4 monoclonal CD22-targeted antibody linked to calicheamicin, a potent anti-tumor antibiotic. CD22 is expressed in more than 90% of patients with B-cell ALL, making it an attractive target in this patient population. Inotuzumab ozogamicin has demonstrated exceptional activity in adults with relapsed or refractory B-ALL. Primary Objective * Assess the efficacy of inotuzumab ozogamicin in patients with MRD positive CD22+ B-ALL with 0.1 - 4.99% blasts in bone marrow. Secondary Objectives * Study the safety of inotuzumab ozogamicin when used in patients with MRD - positive CD22+ B-ALL with \< 5 % blasts in bone marrow. * Estimate the incidence, severity, and outcome of hepatotoxicity and sinusoidal obstruction syndrome/veno-occlusive disease (SOS/VOD) in patients during inotuzumab ozogamicin and following subsequent treatment, including hematopoietic stem cell transplant (HSCT).