This prospective, randomized, multicenter, open-label Phase 2 study is designed to evaluate the superiority of InO monotherapy vs ALLR3 after 1 cycle of induction treatment in paediatric participants (between 1 and \<18 years) with High Risk (HR) or very high risk (VHR) first bone marrow relapse CD22-positive BCP ALL, and to evaluate the safety and tolerability, PK and long-term efficacy. Treatment with study intervention will end after induction therapy; follow-up will continue for up to 5 years from randomization.
Male or female participants between 1 and <18 years of age.
Morphologically confirmed diagnosis of first relapse HR or VHR BCP ALL; HR first relapse is defined as relapse occurring within 18 to 30 months of original diagnosis of ALL or within 6 months of completion of primary therapy, and lacking any identified very high-risk genetic abnormalities (Groeneveld-Krentz et al, 2019) (ie, KMT2A::AFF1 fusion [t(4;11)(q21;q23)], TCF3-HLF fusion [t(17;19)(q22;p13)], TCF3-PBX1 fusion [t(1;19)(q23;p13.3)], hypodiploidy [<40 chromosomes] or masked low hypodiploidy (Molina et al, 2021), TP53 alteration). VHR first relapse is defined as relapse within 18 months of original diagnosis of ALL and/or with any of the following genetic abnormalities at original diagnosis or at relapse (Groeneveld-Krentz et al, 2019) (ie, KMT2A::AFF1 fusion [t(4;11)(q21;q23)], TCF3-HLF fusion [t(17;19)(q22;p13)], TCF3-PBX1 fusion [t(1;19)(q23;p13.3)], hypodiploidy [<40 chromosomes] or masked low hypodiploidy (Molina et al, 2021), TP53 alteration).
CD22-positive ALL as defined by local institution;
Bone marrow involvement of ≥ 5% leukemic blasts (≥ M2 status).
Any history of prior or ongoing hepatic SOS or prior liver failure [defined as severe acute liver injury with encephalopathy and impaired synthetic function (INR of ≥1.5)].
Prior allo-HSCT or CAR T-cell therapy.
Isolated extramedullary leukemia.
Philadelphia-chromosome positive ALL, ie. BCR-ABL/t(9;22) present.