Inclusion Criteria:

        Age

          -  Participants must be < 22 years of age.

        Diagnosis

          -  Participants must have B-ALL with persistent or rising MRD between 0.1 and 4.99%
             without extramedullary disease following at least two prior induction attempts,
             relapse or after hematopoietic stem cell transplant

          -  Leukemia blasts demonstrating surface expression of CD22

        Performance Level

          -  Karnofsky or Lansky performance score ≥ 50% (corresponding to ECOG Score of ≥ 2). The
             Lansky performance score should be used for participants < 16 years and the Karnofsky
             performance score for participants ≥ 16 years.

        Prior Therapy

          -  Patients must have fully recovered from the acute toxic effects of all prior
             anticancer therapy, defined as resolution of all such toxicities to ≤ Grade 2 or lower
             per the inclusion/exclusion criteria prior to entering this study.

          -  At least 14 days must have elapsed since the completion of cytotoxic therapy, with the
             exception of standard maintenance therapy and steroids.

          -  At least 7 days must have elapsed since completion of therapy with a biologic agent.
             For agents that have known adverse events occurring beyond 7 days after
             administration, this period prior to enrollment must be extended beyond the time
             during which adverse events are known to occur.

          -  At least 3 half-lives must have elapsed since prior therapy that included a monoclonal
             antibody with the exception of blinatumomab. Patients must have been off blinatumomab
             infusion for at least 7 days and all drug related toxicity must have resolved to Grade
             2 or lower as outlined in the inclusion/exclusion criteria.

          -  At least 42 days must have elapsed since CAR-T cell therapy.

          -  Participant has received ≤ 1 prior bone marrow transplant.

          -  At least 90 days have elapsed since bone marrow transplant and participant is off
             immune suppression for ≥ 2 weeks, if applicable with no evidence of active GVHD.

          -  At least 2 weeks must have elapsed since local XRT (small port); ≥ 3 months must have
             elapsed if prior cranial or craniospinal XRT was received, if ≥ 50% of the pelvis was
             irradiated, or if TBI was received; ≥ 6 weeks must have elapsed if other substantial
             bone marrow irradiation was given.

        Organ Function Requirements

          -  Adequate renal function defined as glomerular filtration rate ≥ 60 cc/min/1.73m2 or
             serum creatinine based on age as follows:

               -  Age: <6 months; maximum serum creatinine (mg/dL): 0.4 (male, female); Age: 6
                  months to <1 year; maximum serum creatinine (mg/dL): 0.5 (male, female); Age: 1
                  to < 2 years; maximum serum creatinine (mg/dL): 0.6 (male, female); Age: 2 to < 6
                  years; maximum serum creatinine (mg/dL): 0.8 (male, female); Age: 6 to <10 years;
                  maximum serum creatinine (mg/ dL): 1 (male, female); Age: 10 to <13 years;
                  maximum serum creatinine (mg/dL): 1.2 (male, female); Age: 13 to <16 years;
                  maximum serum creatinine (mg/dL): 1.5 (male), 1.4 (female); Age: ≥ 16 years;
                  maximum serum creatinine (mg/dL): 1.7 (male), 1.4 (female)

          -  Adequate hepatic function defined as:

               -  Direct bilirubin ≤ 1.4 mg/dL (if total bilirubin > 1.4 mg/dL) and

               -  AST or ALT ≤ 3 x ULN for age.

          -  Adequate cardiac function defined as shortening fraction of ≥ 27% or ejection fraction
             ≥ 45%.

        Exclusion Criteria:

          -  History of sinusoidal obstruction syndrome/veno-occlusive disease (SOS/VOD) of any
             severity.

          -  Concurrent chemotherapy or targeted anti-cancer agents, other than intrathecal
             therapy.

          -  Patient with concurrent severe and/or uncontrolled medical conditions that, in the
             opinion of the investigator, may impair participation in the study or the evaluation
             of safety and/or efficacy.

          -  Known HIV infection or active hepatitis B (defined as hepatitis B surface
             antigen-positive) or C (defined as hepatitis C antibody-positive).

          -  Pregnant or lactating (female participant of childbearing potential must have negative
             serum or urine pregnancy test required within 7 days prior to start of treatment).

          -  Male or female participant of reproductive potential must agree to use appropriate
             methods of contraception for the duration of study treatment and for at least 30 days
             after last dose of protocol treatment.

          -  Inability or unwillingness of research participant or legal guardian/representative to
             give written informed consent.