Abstract Introduction: KTE-C19 is an autologous anti-CD19 CAR T cell product that is being studied in a phase 2 multicenter trial (ZUMA-1, NCT02348216). We developed a robust and efficient manufacturing process to support this trial, and compared the characteristics of the starting lymphocytes to resultant CAR T cells. Methods: After apheresis and PBMC enrichment, cells were activated with anti-CD3 antibody and cultured in serum free medium. T cells were transduced with a retroviral vector encoding the CAR gene, expanded to achieve a target dose and cryopreserved. The product CAR T cells and the starting PBMCs were evaluated by flow cytometry. Results: 7 subjects were dosed in the phase 1 portion of the trial. KTE-C19 was successfully manufactured at a dose of 2 × 106/kg (minimum 1 × 106/kg) for all subjects. All lots contained mainly CD3+ T cells (median 97%; 94-99%). While there was inter-subject variability in PBMC and CAR T cell product characteristics, the CD8/CD4 T cell ratios in PBMC and corresponding CAR product were similar (Table 1). T cells in PBMC from patients with NHL contained a majority of effector memory (36%) and effector T cells (27%), however, T cells in KTE-C19 contained a majority of central memory (37%) and effector memory (42%) CAR+ T cells. These CAR T cells were active and objective responses occurred in 5/7 patients. Conclusions: A KTE-C19 dose was successfully produced for all subjects. The optimized manufacturing process generated clinically active CAR T cells with a less differentiated phenotype than T cells in the starting PBMC population. Less differentiated cells likely confer preferred product characteristics based on preclinical studies. This manufacturing process is robust and well suited for multicenter clinical trials. Table 1.Comparative analysis of T cells from KTE-C19 and PBMC from patients with refractory aggressive NHL.IDSampleNaïve (%)Central Memory (%)Effector Memory (%)Effector (%)CD8/CD4 ratioSubject 1KTE-C1911583014.6PBMC161246272.3Subject 2KTE-C1914473540.37PBMC26303490.27Subject 3KTE-C196345642.3PBMC4536552.9Subject 4KTE-C19111552222.0PBMC1224721.8Subject 5KTE-C1915403871.0PBMC91550261.1Subject 6KTE-C1919344252.3PBMC101359192.0Subject 7KTE-C19152645140.5PBMC121336390.5Median (Range)KTE-C1913 (6-15)37 (15-58)42 (30-56)5 (1-22)1.9 (0.4-4.6)PBMC10 (1-26)13 (2-30)36 (24-59)27 (9-72)1.9 (0.3-2.9) Citation Format: Marc Better, Vijay Chiruvolu, James Oliver, Maryam Sorkhabi, Jeff S. Aycock, Emily Lowe, Edmund Chang, Arianne Perez, Lynn Navale, John M. Rossi, Adrian Bot. Manufacturing and characterization of KTE-C19 in a multicenter trial of subjects with refractory aggressive non-Hodgkin's lymphoma (NHL) (ZUMA-1). [abstract]. In: Proceedings of the 107th Annual Meeting of the American Association for Cancer Research; 2016 Apr 16-20; New Orleans, LA. Philadelphia (PA): AACR; Cancer Res 2016;76(14 Suppl):Abstract nr 2308.