Blinatumomab is a CD19- and CD3-targeting (CD19 × CD3) BsAb that the FDA approved in 2014 for the treatment of relapsed/refractory B-ALL [20], and is currently undergoing phase I/II clinical trials in other hematological malignancies such as diffuse large B-cell lymphoma and NHL [57]. Here, CD19 is linked to precursor B-cell acute lymphoblastic leukemia.