CD19 chimeric antigen receptor T cell therapy for the treatment of B cell lineage acute lymphoblastic leukemia

Relapsed and refractory acute lymphoblastic leukemia (ALL) remains difficult to treat, with minimal improvement in outcomes despite advances in upfront therapy and improved survival for de novo ALL. Targeted immunotherapy for cancer represents a promising new treatment and utilizing the immune system to target and eradicate malignant cells in the body has emerged as a potent therapy. Administration of cytotoxic T cells genetically engineered to express a chimeric antigen receptor (CAR) recognizing CD19 have been shown to induce complete responses in patients with B-cell lineage ALL. So far, six clinical trials including 79 ALL patients treated with CD19-CAR T cells have been published, and the results from these trials are exciting with impressive clinical responses. Thus, CAR T cell therapy represents a potential useful tool to ALL. However, the majority of CAR cell studies have observed severe therapy associated toxicities, which needs attention. In this review, we mainly focus on CD19-CAR T cells, clinical trials for ALL as well as toxicities and challenges for CD19-CAR T therapy.