195. Allogeneic CD19-CART Therapy to the Rescue of a Pediatric Patient with Relapsed and Refractory Acute B Lymphoblastic Leukemia

Acute B lymphoblastic leukemia (B-ALL) is a common hematological malignancy in children. Using a fourth generation, safety-switch inserted, chimeric antigen receptor (4SCAR) technology, we have treated more than 200 patients with B-ALL in China, with an overall complete remission rate of more than 80% (ASH 2015). Here we report the case of a 7-year-old girl with a high load of refractory B-ALL, who was heavily pretreated with chemotherapy but relapsed with u003e80 leukemic blasts in her bone marrow. The patient received CD19-4SCAR T cells generated from her motheru0027s peripheral blood T cells (allo-4SCAR19) for three times at total of 0.76 x106 CART/kg on day 0, 4, and 7, followed by an infusion of autologous 4SCAR19 (auto-4SCAR19) at total of 0.16 x106 CART/kg on day 56, which was derived from the patientu0027s own T cells after her immune recovery. Complete remission was achieved as revealed by bone marrow examination on day 77. Graft versus host disease signs were not observed throughout the days following the infusions, and the syndrome of suspected cytokine storm was generally mild. The only adverse responses were intermittent fever and skin rashes following allo-4SCAR19 infusions which lasted for about 20 days. The outcome of this case suggests that allo-4SCAR19 may be a safe approach in treating B-ALL patients who could not provide their own T cells for CART engineering, and allo-4SCAR19 combined with auto-4SCAR19 is a novel strategy that may rescue chemo-refractory, high-risk and highly immune suppressed leukemia patients.