Abstract 1631: T cell dysfunction in pediatric cancer patients at diagnosis and after chemotherapy can limit chimeric antigen receptor potential

Cellular therapy using engineered T cells has demonstrated clinical efficacy in the treatment of hematologic malignancies. Many patients, however, have T cells that result in a poor clinical product that either fails manufacture or does not proliferate in the patient. We have prospectively characterized peripheral blood T cells from 157 pediatric cancer patients and identified key metabolic changes associated with CAR T cell potential. We collected peripheral blood samples from 157 pediatric patients with acute lymphoblastic leukemia (ALL), non-Hodgkin Lymphomas (NHL) , neuroblastoma, osteosarcoma, rhabdomyosarcoma, Wilms, Hodgkins, chronic myelogenous leukemia and Ewings sarcoma at diagnosis and after each cycle of chemotherapy. We depleted the adherent cells from this collection, quantified the CD3+ population using flow cytometry, and expanded these T cells using CD3/CD28 stimulatory beads as in CAR T cell manufacturing. We noted very poor CAR T cell potential in all tumor types ( Citation Format: Rajat K. Das, Julie Storm, David M. Barrett. T cell dysfunction in pediatric cancer patients at diagnosis and after chemotherapy can limit chimeric antigen receptor potential [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2018; 2018 Apr 14-18; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2018;78(13 Suppl):Abstract nr 1631.