Immunotherapy for relapsed pediatric leukemia treatment is now more common [inotuzimab, blinatumomab, CAR-T]. Leading child leukemia and precision medicine expert discusses progress in child cancer treatment and lessons learned from immunology. Many children are now being cured of leukemia. Dr. Anton Titov, MD. But, unfortunately, in some children, leukemia returns. There is a relapse of leukemia. You specialize in therapy of treatment- resistant leukemia and relapsed leukemia. Dr. Anton Titov, MD. What is new in treatment of relapsed leukemia? Dr. Shai Izraeli, MD. In the field of acute lymphoblastic leukemia (ALL), we are in a very exciting time. The exciting time comes from the development of cancer immunotherapy. Currently cancer immunotherapy exists only for the most common subtype of acute lymphoblastic leukemia (ALL). It is a B cell acute leukemia. It constitutes 85% of all acute lymphoblastic leukemia. Dr. Shai Izraeli, MD. We learned a long time ago that it is a hereditary disease. It's called Bruton agammaglobulinemia. Patients with Bruton agammaglobulinemia have no B cells. It used to be lethal. But now we have cancer medications that are called immunoglobulins. These are the antibodies. Dr. Anton Titov, MD. Children with Bruton agammaglobulinemia can grow and be adults after therapy with immunoglobulins. We learned from Bruton agammaglobulinemia therapy that you can give immunoglobulins, antibodies. Then B cells are not essential for survival of patients. This really opened the door for treatment against surface antigens on the surface of the immune cells. This is cancer immunotherapy that kills B cells. It kills both the normal and the leukemic cancer cells. Dr. Shai Izraeli, MD. But we can get over the loss of normal cells by giving immunoglobulins. There are actually three types of cancer immunotherapy. All of them are now quite effective in the clinical trials. I believe they will enter therapy of relapsed leukemia. Immunotherapy will be used in high risk leukemias as a first-line treatment. Dr. Anton Titov, MD. One type of cancer immunotherapy are antibodies that are conjugated to toxins. The antibodies recognize the leukemic cells. Leukemia cells swallow the antibody. But this antibody is like a trojan horse. Immunotherapy cancer medication also carries a toxin. This toxin is released inside the leukemia cells. Toxin kills cancer cells. That's one example. The name of medication is inotuzumab [Besponsa]. It is an example of leukemia treatment with cancer immunotherapy antibody. There are other type of leukemia treatment antibodies. These are called bi-specific antibodies. This is an antibody that has two heads. One head targets the leukemia antigen. The other head targets T cell. This child leukemia therapeutic antibody brings T cells to the leukemic cells. These are the patient's T cells. T cells are a type of immune cells. Dr. Shai Izraeli, MD. Antibody brings T cells to the vicinity of the leukemia cell. Then the T cell eats the leukemic cell. An example of such leukemia cancer immunotherapy antibody is blinatumomab (Blincyto). This is an unbelievable development of genetic engineering. T cells are called CAR T-cells. This leukemia therapy is very important. Maybe the Nobel Prize will be given for CAR T-cell therapy. That this was invented by an Israeli scientist. His name is Dr. Zelig Eshhar. He developed them in the 1980s. He called them T-bodies. In CAR T-cell therapy, immune T cells are harvested from the patient's body. Dr. Anton Titov, MD. Then in cell culture in the laboratory they are engineered. An antibody against B-cells is put into these T-cells. Then these T-cells are injected back to a patient. Then these T-cells are coming and finding the leukemia cells, and they kill cancer cells. Dr. Shai Izraeli, MD. These are the incredibly exciting new cancer treatments that we have now against relapsed child leukemia.