Multicenter phase II trial of inotuzumab ozogamicin for R/R B-ALL in children and adolescents

Effective and safe therapies that bridge to potentially curative HSCT or CAR T-cell therapy are critical to improving outcomes for patients with relapsed or refractory B-cell acute lymphoblastic leukemia. Although inotuzumab ozogamicin (InO) is effective in adults, studies in children are limited. The multicenter phase II AALL1621 trial by the Children’s Oncology Group evaluated InO for R/R CD22-positive B-ALL. The study showed that InO was well tolerated and effective with high response rates and minimal residual disease <0.01% in two thirds of responders. A significant proportion of responding patients proceeded to HSCT and/or CAR T-cell therapy. For patients proceeding to HSCT after InO, sinusoidal obstruction syndrome was a significant toxicity.