The Phase I part of the study aims to evaluate the safety, efficacy, and tolerability of subcutaneous (SC) blinatumomab for treatment of Relapsed or Refractory B cell Precursor Acute Lymphoblastic Leukemia (R/R B-ALL), to determine the maximum tolerated dose (MTD), and recommended phase 2 dose(s) (RP2D) of SC administered blinatumomab.

The Phase II part of the study will evaluate the safety, efficacy, and tolerability of SC blinatumomab for treatment of R/R B-ALL and Minimum Residual Disease Positive (MRD+) B-ALL in participants 12 years old and greater. It will also conduct a clinical pharmacokinetic (PK) evaluation of SC1 and SC2 blinatumomab formulations.

Inclusion Criteria:

• Ph-IIC, Dose Escalation and Dose Expansion: Aged 18 years or older (or same or greater than legal age within the country if it is older than 18 years).

• Ph-IIRa and Ph-IIMa: Aged ≥ 17 years at time of informed consent.

• Ph-IIRb and Ph-IIMb: Age ≥ 12 years and < 17 years at time of informed consent.

• Ph-IIR, Ph-IIC, Dose escalation, Dose Expansion: Participants with R/R B-precursor ALL.

• Relapsed or Refractory B-precursor ALL at any time after first salvage therapy.

• Relapsed B-precursor ALL at any time after allogenic hematopoietic stem cell transplant (HSCT).

• Ph-IIR, Ph-IIC, Dose escalation, Dose expansion: Greater than or equal to 5% blasts in the Bone Marrow per local assessment.

• Ph-IIM: B-precursor ALL and bone marrow blasts (BMB) ≥ 0.01% and < 5% per local assessment.

• Ph-IIM: Availability of an appropriate archival BM specimen from initial or relapse diagnosis and the screening BM sample.

• Participants aged ≥ 18 years: Eastern Cooperative Oncology Group (ECOG) Performance Status less than or equal to 2.

• Participants aged 16 to < 18 years old: Karnofsky Performance Score ≥ 50%.

• Participants aged < 16 years old: Lansky Performance Score ≥ 50%.

• Any Ph+ participant intolerant or refractory to prior tyrosine kinase inhibitors (TKIs) are eligible.

• Ph-IIM: BM function as follows:

  • Absolute Neutrophil Count (ANC) ≥ 500/μL
  • Platelet count ≥ 50 000/μL (transfusion permitted)
  • Hemoglobin level ≥ 9 g/dL (transfusion permitted)

The above is a summary, other inclusion criteria details may apply.

Exclusion Criteria:

• Active ALL in the central nervous system (CNS). Presence of greater than 5 white blood cells per cubic millimeter in cerebrospinal fluid (CSF) with lymphoblasts present and/or clinical signs of CNS leukemia. If CSF leukemia is present subjects will have to receive intrathecal therapy and have documented negative CSF prior to enrolling.
• History or presence of clinically relevant CNS pathology (excluding headache) such as epilepsy, childhood or adult seizure, paresis, aphasia, stroke, severe brain injuries, dementia, Parkinson's disease, cerebellar disease, organic brain syndrome, psychosis or severe (≥ grade 3) CNS events including immune effector cell-associated neurotoxicity syndrome (ICANS) from prior chimeric antigen receptor T-cell (CAR T) or other T cell engager therapies.
• Isolated Extramedullary (EM) Disease.
• For Ph-IIM only: Current EM disease or presence of circulating leukemia blasts.
• Current autoimmune disease or history of autoimmune disease with potential CNS involvement.
• Active acute or chronic graft versus host disease requiring systemic treatment with immunosuppressive medication.
• Symptoms and/or signs that indicate an acute or uncontrolled chronic infection, any other disease or condition that could be exacerbated by the treatment or would complicate protocol compliance.
• Testicular leukemia.
• History of malignancy (with certain exceptions) other than ALL within 3 years prior to start of protocol-specified therapy.
• Allogeneic HSCT within 12 weeks before the start of protocol-specified therapy.
• Cancer chemotherapy within 2 weeks before the start of protocol-specified therapy (with certain exceptions).
• Immunotherapy within 4 weeks before start of protocol-specified therapy.
• Prior failed cluster of differentiation (CD19) directed therapy such as prior blinatumomab or CD19 CAR T cells will be allowed (with demonstrated continued CD19+ expression), if treatment ended more than 4 weeks prior to start of protocol therapy and no prior CNS complications.
• Currently receiving treatment in or less than 30 days or 5 half-lives since ending treatment on another investigational study(ies).
• Abnormal screening laboratory parameters.
• Female participant: Pregnant or breastfeeding or planning to become pregnant or donate eggs, or expected to breastfeed during treatment and for 96 hours after the last dose of investigational product (SC blinatumomab).

The above is a summary, other exclusion criteria details may apply.

De-identified individual patient data for variables necessary to address the specific research question in an approved data sharing request.

Data sharing requests relating to this study will be considered beginning 18 months after the study has ended and either 1) the product and indication have been granted marketing authorization in both the US and Europe or 2) clinical development for the product and/or indication discontinues and the data will not be submitted to regulatory authorities. There is no end date for eligibility to submit a data sharing request for this study.

Qualified researchers may submit a request containing the research objectives, the Amgen product(s) and Amgen study/studies in scope, endpoints/outcomes of interest, statistical analysis plan, data requirements, publication plan, and qualifications of the researcher(s). In general, Amgen does not grant external requests for individual patient data for the purpose of re-evaluating safety and efficacy issues already addressed in the product labelling. Requests are reviewed by a committee of internal advisors. If not approved, a Data Sharing Independent Review Panel will arbitrate and make the final decision. Upon approval, information necessary to address the research question will be provided under the terms of a data sharing agreement. This may include anonymized individual patient data and/or available supporting documents, containing fragments of analysis code where provided in analysis specifications. Further details are available at the URL below.