Study of Blinatumomab Administration in Chinese Pediatric Participants With Relapsed/Refractory B Precursor Acute Lymphoblastic Leukemia (R/R B-ALL)

Inclusion Criteria:

• Participant's parent or legally authorized representative has provided informedconsent when the participant is legally too young to provide informed consent andthe participant has provided written assent based on local regulations and/orguidelines prior to any study-specific activities/procedures being initiated

• Pediatric participants aged > 1 month and < 18 years at the time of informed consent

• Relapsed or/refractory precursor B-cell acute lymphoblastic leukemia (ALL) disease,defined as ≥5% bone marrow blasts with at least one of the following:

• Second or later bone marrow relapse;

• Any marrow relapse after allogeneic hematopoietic stem cell transplant (alloHSCT);

• Refractory to other treatments:

• For participants in first relapse: failure to achieve a complete remission (CR)following a full standard reinduction chemotherapy regimen

• For participants who have not achieved a first remission, failure to achieveremission following a full standard induction regimen

• Karnofsky performance status ≥ 50% for participants ≥ 16 years

• Lansky performance status ≥ 50% for participants < 16 years

Exclusion Criteria:

• Evidence of current central nervous system (CNS) involvement by ALL. Participants with CNS disease at the time of relapse are eligible if CNS is successfully treated prior to enrollment.

Other Medical Conditions

• Clinically relevant CNS pathology requiring treatment (eg, unstable epilepsy).

• Isolated extramedullary (EM) disease.

• Active malignancy other than ALL.

• Burkitt's leukemia according to the World Health Organization (WHO) 2016 criteria.

• Abnormal renal or hepatic function at screening as defined below:

• Abnormal serum creatinine based on age/gender as described by Threshold CreatinineValues

• Direct bilirubin > 1.5 mg/dl (25.6 μmol/L) at screening (unless related to Gilbert'sor Meulengracht disease).

• Symptoms and/or clinical signs and/or radiological and/or sonographic signs thatindicate an acute or uncontrolled chronic infection, any other concurrent disease ormedical condition that could be exacerbated by the treatment or would seriouslycomplicate compliance with the protocol.

• Known infection with human immunodeficiency virus (HIV) or chronic infection withhepatitis B virus (hepatitis B surface antigen [HBsAg] positive) or hepatitis Cvirus (HCV) (anti-HCV positive).

• Known hypersensitivity to blinatumomab or any of the products or components of theblinatumomab formulation.

Prior/Concomitant Therapy

• AlloHSCT within 12 weeks prior to start of protocol-specified therapy.

• Active acute or chronic Graft-versus-Host-Disease (GvHD) requiring systemictreatment with immunosuppressive medication.

• Radiotherapy within 2 weeks prior to start of protocol-specified therapy.

• Immunotherapy (eg, rituximab) within 4 weeks prior to start of protocol-specifiedtherapy. Prior failed cluster of differentiation 19 (CD19) directed therapy such asprior blinatumomab or CD19 chimeric antigen receptor T cells (CAR T cell) will beallowed (with demonstrated continued CD19+ expression) if treatment ended > 4 weeksprior to start of protocol-specified therapy.

• Cancer chemotherapy within 2 weeks before the start of protocol-specified therapy.With the exception of intrathecal chemotherapy and/or low dose maintenance therapyfor example vinca alkaloids, mercaptopurine, methotrexate, or hydroxyurea orpre-phase chemotherapy and/or dexamethasone. Any low dose chemotherapy as statedabove must be discontinued before starting pre-phase.

Prior/Concurrent Clinical Study Experience

• Currently receiving treatment in another investigational device or drug study, or less than 4 weeks since ending treatment on another investigational device or drug study(ies). Other investigational procedures while participating in this study are excluded.

Other Exclusions

• Female participants of childbearing potential with a positive pregnancy testassessed at Screening by a highly sensitive urine or serum pregnancy test.

• Female participants who are breastfeeding or who plan to breastfeed while on studythrough 12 months after the last dose of protocol-required treatment with highestteratogenic risk.

• Female participants of childbearing potential unwilling to use protocol-specifiedmethod of contraception during treatment and for an additional 12 months after thelast dose of protocol-required treatment with highest teratogenic risk.

• Male participants with a female partner of childbearing potential who are unwillingto practice sexual abstinence (refrain from heterosexual intercourse) or usecontraception during treatment and for an additional 6 months after the last dose ofprotocol-required therapy with highest teratogenic risk.

• Participant likely to not be available to complete all protocol-required studyvisits or procedures, and/or to comply with all required study procedures to thebest of the participant and investigator's knowledge.

• Female participants planning to become pregnant while on study through 12 monthsafter the last dose of protocol-required treatment with highest teratogenic risk.

• Male participants unwilling to abstain from donating sperm during treatment and foran additional 6 months after the last dose of protocol-required treatment withhighest teratogenic risk.