In May 2019, the U.S. Food and Drug Administration (FDA) added new clarifications to its risk evaluation and mitigation strategy (REMS) and black box warnings for blinatumomab (Blincyto®). Blinatumomab is a bispecific, CD19-directed CD3 T-cell engager indicated for the treatment of adults and children with (a) B-cell precursor acute lymphoblastic leukemia (ALL) in first or second complete remission with minimal residual disease (MRD) greater than or equal to 0.1% or (b) relapsed or refractory B-cell precursor ALL.