A Phase 3 Randomized Trial of Inotuzumab Ozogamicin for Newly Diagnosed High-Risk B-ALL: Safety Phase Results from Children's Oncology Group Protocol AALL1732

Background: The CD22-directed antibody-drug conjugate inotuzumab ozogamicin (InO) is FDA-approved for adults with relapsed/refractory (R/R) CD22+ B-ALL and highly active in children with multiply R/R CD22+ B-ALL. Notable toxicities include cytopenias and hepatic toxicity, including sinusoidal obstruction syndrome (SOS) occurring primarily after subsequent hematopoietic stem cell transplantation (HSCT). The incorporation of InO into frontline ALL therapy for patients (pts) with CD22+ high-risk B-ALL who are not anticipated to require HSCT in first remission may optimize use of this effective agent without incurring significant SOS risk by minimizing relapse and therefore potential need for future HSCT.