Post-Marketing Use Outcomes of an Anti-CD19 Chimeric Antigen Receptor (CAR) T Cell Therapy, Axicabtagene Ciloleucel (Axi-Cel), for the Treatment of Large B Cell Lymphoma (LBCL) in the United States (US)

Introduction Axi-cel is approved in the US for the treatment of adult patients with relapsed or refractory large B cell lymphoma after 2 or more lines of systemic therapy. A post-marketing study is ongoing in the US utilizing the infrastructure created by the Center for International Blood and Marrow Transplant (CIBMTR) for post-approval safety and efficacy assessment and to follow these patients for 15 years through the established cellular therapy registry. This is the first year analysis of this study. Methods From October 18, 2017 to May 1, 2019, 453 axi-cel recipients were voluntarily reported to the CIBMTR. Of these, 295 patients from 43 US centers that have at least the first follow-up assessment submitted at 3 months were included in this analysis. Median follow-up was 6 months (range, 1-14 months). Results The median age overall was 61 years, 101 (34%) patients were ≥ 65 years, and 197 (67%) patients were male (Table 1). Baseline clinical characteristics included Eastern Cooperative Oncology Group (ECOG) performance score 0-1 (77%), transformed lymphoma (27%), double-hit lymphoma (36%), prior autologous transplant (34%), and chemotherapy-resistant disease (66%) prior to axi-cel. The median time from diagnosis to axi-cel infusion was 18 months (range 2-274 months). Overall response rate (ORR) was 70% (complete response [CR] 52% and partial response [PR] 18%). Patients ≥ 65 years were generally comparable vs younger patients with a slightly better CR rate (62% vs 46%, p=0.03) but similar overall response rate (CR+PR, 75% vs 67%, p=0.26). Cytokine release syndrome (CRS) of any grade was reported in 83% of patients. Incidence of Grades ≥ 3 CRS according to Lee et al 2014 was 11%, and was 14% according to American Society for Transplantation and Cellular Therapy (ASTCT) Consensus Grading (Table 2). Two patients died due to CRS. Median time to any grade CRS was 3 days (range, 1-17 days), and 94% of CRS cases resolved with a median duration of 7 days (range, 1-121 days). Among patients with CRS, tocilizumab, corticosteroids and siltuximab were used in 70%, 26% and 1% of cases, respectively. Neurologic adverse events (AEs) of any grade occurring after axi-cel infusion were reported in 181 (61%) patients. One patient was reported to die from cerebral edema. Additional information on neurologic AE severity will be presented. The median time to onset of any grade neurologic AEs was 6 days (range, 1-82 days), and 88% resolved by time of data submission with a