Inotuzumab-Ozogamicin-B1931036

This prospective, randomized, multicenter, open-label Phase 2 study is designed to evaluate the superiority of inotuzumab ozogamicin (InO) monotherapy compared with ALLR3 therapy following one cycle of induction treatment in pediatric participants (aged 1 to <18 years) with a first high-risk bone marrow relapse of CD22-positive B-cell precursor acute lymphoblastic leukemia (BCP-ALL). The study will also assess the safety and tolerability, pharmacokinetics (PK), and long-term efficacy of the treatment. Study treatment ends after completion of induction therapy; however, follow-up for efficacy and safety will continue for up to 5 years after randomization.

The end of treatment is defined as either the completion of one cycle of study therapy (Day 28 ± 2 days) or the day before initiation of a new anticancer therapy, whichever occurs first.

Approximately 100 participants will be randomized in a 2:1 ratio to receive either one cycle of InO monotherapy or ALLR3 therapy (Block 1) during the induction phase.

Following completion of induction therapy (i.e., the study treatment), most participants who respond to treatment are expected to proceed directly to consolidation therapy. Participants who do not respond to induction therapy may receive further treatment at the discretion of the treating study team. For participants who respond to induction therapy, transition to standard-of-care (SOC) consolidation therapy is expected after recovery of blood counts, but no earlier than 7 days after the last dose of study treatment.

All participants, including both responders and non-responders, will continue to be followed long term as part of this study. Any subsequent anticancer therapies will be determined by the treating physician.