CD19 and acute lymphoblastic leukemia: The BiTE blinatumomab is the first of the above agents to be approved beyond off-label use and is indicated as monotherapy for the treatment of children aged one year or older with Philadelphia chromosome negative (Ph−) CD19+ B-precursor acute lymphoblastic leukemia (ALL) which is refractory or in relapse (r/r) after receiving at least two prior therapies or in relapse after receiving prior allogeneic hematopoietic stem cell transplantation (AHSCT) [8].