AALL1821: A Phase 2 Study of Blinatumomab (NSC# 765986, IND# 125462) in Combination with Nivolumab (NSC# 748726, IND# 125462), a Checkpoint Inhibitor of PD-1, in B-ALL Patients Aged >/=1 to <31 Years Old with First Relapse

This is a study looking at how well the combination treatment of Blinatumomab and Nivolumab works in patients with first relapse of B-cell Acute Lymphoblastic Leukemia (B-ALL) as compared to treatment with only Blinatumomab. In addition, it is looking at what effects, good and/or bad the treatment has. First relapse means that B-ALL has come back after the initial treatment a patient received for B-ALL. All patients will receive treatment with Blinatumomab, an antibody (protein) that targets a marker on B-ALL cells and then uses your immune system to kill the B-ALL cell. Some patients will also receive Nivolumab. Nivolumab is a medicine that boosts a person's immune system. The treatment a patient receives on this study is decided upon by randomization, which is a process that decides something by chance, similar to flipping a coin. In this study, the randomization will be done by a computer.

Are you Eligible? (Inclusion Criteria)

• Patient must be at least 1 year and < 31 years of age
• Patient must be in first relapse of B-ALL
• Patient must also meet all other eligibility criteria as outlined in the study protocol