Abstract CT041: The clinical study on CD19-directed chimeric antigen receptor-modified T cells in patient with Richter Syndrome

Abstract

Abstract Richter syndrome (RS) indicates the transformation of chronic lymphocytic leukemia (CLL) into an aggressive lymphoma (mostly DLBCL). RS is a rare complication with unfavorable clinical outcome. There is no effective treatment for it currently. As a new type of cell-based immune therapy, chimeric antigen receptor modified T (CAR-T) cell treatment is now widely used in treating hematological malignancies, especially in CD19+ B cell malignancy. Therefore, CD19-directed chimeric antigen receptor modified T cells (CART-19) treatment is worthwhile to be developed as a new method for Richter Syndrome’s patients. In this study, the patient with Richter Syndrome expressing high level of CD19 was enrolled in a clinical trial. The patient had received a series of standard treatments with no therapeutic effect before 4.55 x 108 autologous CART-19 cells were infused, of which approximately 50% were transduced with the CAR. After CART-19 infusion, the main side effects were repeated fever, pancytopenia and significant rises of serum cytokines, including IFN-γ, IL-6 and IL-10. However, before discharge, the level of cytokines reduced to normal level. In addition, we detected K+, Ca2+, creatinine and glutamic-pyruvic transaminase, and found all of these were normal, which suggested that there was no significant tumor necrosis after treatment. The treatment included two courses. During the first course, the patient was infused with 4 x 107 CART-19 cells twice, followed by 1 x 108 cells in the 3rd infusion and then 1x106 cells in the 4th infusion. After these infusions, the proportion of B cells in the patient’s peripheral blood decreased from 72% to 40%, accompanied by reduced size of cervical, mediastinal and axillary lymph nodes. Eighteen days later, the patient was infused in the second course with 3.7x107 CART-19 cells twice, followed by 1x108 cells twice. After the second course, the proportion of B cells maintained at approximate 85%, and the lymph nodes enlargement was observed as disease progression. Based on the recent therapeutic landscape for hematological malignancies including B cell lymphomas, CD19-CAR T cell therapy may offer a new therapeutic option for RS, which aims to reduce the patients’ tumor burden, prolong their survival time, and provide opportunities for combined therapy with chemotherapy and bone marrow transplantation. Note: This abstract was not presented at the meeting. Citation Format: Leiming Xia, Qian Chen, Qiao Li, Tan Li, Yi Wang, Yangyi Bao. The clinical study on CD19-directed chimeric antigen receptor-modified T cells in patient with Richter Syndrome [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2017; 2017 Apr 1-5; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2017;77(13 Suppl):Abstract nr CT041. doi:10.1158/1538-7445.AM2017-CT041