Inotuzumab ozogamicin in pediatric relapsed/refractory B-cell precursor acute lymphoblastic leukemia

Abstract

Inotuzumab ozogamicin (InO) was approved in Japan in March 2024 to treat pediatric patients with CD22-positive relapsed/refractory B-cell precursor acute lymphoblastic leukemia (R/R BCP-ALL). In this study, we investigated the efficacy and safety of InO in nine patients with R/R BCP-ALL. Eight patients in non-remission and one patient in remission received InO as bridging therapy. Of the eight patients, five achieved complete remission (CR), whereas three were refractory. Of the five patients with CR, the disease eventually relapsed in four; however, InO was re-administered in two of these patients, and both patients achieved CR again. Nonhematologic toxicities of common terminology criteria for adverse events grade ≥3 included febrile neutropenia, infusion reaction, elevated aspartate transaminase/alanine aminotransferase, and sinusoidal obstruction syndrome in one patient. InO is an effective treatment option for remission induction therapy in patients with CD22-positive R/R BCP-ALL. Re-administration of InO may be effective, particularly in patients with prior InO administration.