Inclusion criteria:

          -  Participant must be 28 days to less than 18 years of age, at the time of signing the
             informed consent.

          -  Participants must have a confirmed diagnosis of relapsed Acute Lymphoblastic Leukemia
             (ALL) of T- or B-cell origin including T-lymphoblastic lymphoma (LBL), or relapsed
             Acute Myeloblastic Leukemia (AML) including participants with history of
             myelodysplasia.

          -  Participants must be previously treated for their disease and have relapsed or are
             refractory to most recent treatment. Participants in first or second relapse will be
             eligible regardless of the remission duration.

          -  Participants with no more than 1 prior salvage therapy.

          -  WBC counts below 20 x109/L on Day 1 before isatuximab administration

        Exclusion criteria:

          -  Any serious active disease or co-morbid condition which, in the opinion of the
             Investigator, may interfere with the safety of the study treatment or the compliance
             with the study protocol.

          -  Participants must have been off prior treatment with immunotherapy/investigational
             agents and chemotherapy for >2 weeks and must have recovered from acute toxicity
             before the first study treatment administration. Exceptions are participants who need
             to receive cytoreductive chemotherapy in order to decrease tumor burden (the study
             treatment may start earlier if necessitated by the patient's medical condition (eg,
             rapidly progressive disease) following discussion with the Sponsor).

          -  Prior stem cell transplant within 3 months and/or evidence of active systemic Graft
             versus Host Disease (GVHD) and/or immunosuppressive therapy for GVHD within 1 week
             before the first study treatment administration.

          -  Participants with LBL with bone marrow blasts <5%.

          -  Participants with Burkitt-type ALL.

          -  Acute leukemia with testicular or central nerve system involvement alone.

          -  Participants who have developed therapy related acute leukemia.

          -  Live vaccine(s) within 30 days prior to the first IMP administration or plans to
             receive such vaccines during the study until 90 days after the last IMP
             administration.

          -  Participants with white blood cell count > 50 x109/L at the time of screening visit.

          -  Participants who have been exposed to anti-CD38 therapies within 6 months prior to
             Day-1.

        The above information is not intended to contain all considerations relevant to a patient's
        potential participation in a clinical trial.