The use of novel monoclonal antibodies in the treatment of acute lymphoblastic leukemia.

Regardless of age, patients with relapsed or refractory acute lymphoblastic leukemia (ALL) have extremely poor outcomes. The success of reinduction chemotherapy remains dismal, because complete remission rates are low and seldom durable. Clearly, new and novel strategies are needed to improve the outcome of patients with relapsed or refractory ALL. Patients with early relapse, especially those still receiving chemotherapy, tend to have a much poorer outcome and are often chemotherapy resistant. Although high-dose approaches may overcome chemotherapy resistance, long-term disease-free and overall survival remains limited. Several approaches have been used to target antigens, including cluster of differentiation (CD) 19, CD20, CD22, and CD52, on the surface of the malignant lymphoblast with striking efficacy. This review will focus on the clinical application of the major classes of antibodies, including naked antibodies, drug-antibody conjugates, immunotoxins, and T cell-engaging bispecific antibodies. Hopefully, these novel monoclonal antibodies will result in a significant improvement in the outcome of patients with relapsed or refractory ALL.