Outcomes of Patients Requiring ICU Admission after CD19 Directed CAR T-Cells
Authors: Lin Erica , Jeong Ah-Reum , Hurley Michael , Owens Robert L , Tzachanis Dimitrios , Goodman Aaron M 
Published: November 2020

Introduction:Chimeric antigen receptor (CAR) T-cells are engineered T-cells that target specific antigens on tumor cell surfaces. CD19 directed CAR T-cells have demonstrated efficacy in B-cell lymphomas and B-cell acute lymphoblastic leukemia (B-ALL); however, patients are at risk for life-threatening complications including cytokine release syndrome (CRS) and immune effector cell-associated neurotoxicity syndrome (ICANS). Grade 3 ICANS and higher have been reported in 12-28% and Grade 3 CRS and higher in 1-23% in pivotal studies for B-cell lymphoma.1 The majority, if not all, patients with Grade 3 ICANS and CRS require intensive care unit (ICU) admission. The long-term outcomes of patients requiring ICU admission after CD19 directed CAR T-cells are unknown.
Methods:Clinical data were retrospectively reviewed from consecutive patients with relapsed or refractory B-cell lymphomas and B-ALL treated with axicabtagene ciloleucel or tisagenlecleucel at a single institution from January 1, 2016 to July 1, 2020. Diagnosis of CRS and ICANS was based on the American Society for Transplantation and Cellular Therapy consensus grading.2 Demographics, medical co-morbidities, therapeutic interventions, relapse rate, and all-cause mortality were assessed.
Results:Thirty-seven patients received CAR T-cells. Sixty-seven percent (n=25) of patients were male with a median age of 55 years (range 23 - 77). Eighty-nine percent of patients had large B cell lymphoma. Patients received a median of 3 prior therapies (range 1 - 6). The median IPI and ECOG scores at time of CAR T-cells administration were 3 and 1, respectively. Forty-three percent (n=16) of patients required ICU admission. The median length of ICU stay was 3.5 days (range 1 - 18). The median CRS and ICANS grades in patients requiring ICU admission were 2 and 3, compared to 2 and 0 in patients not requiring ICU admission, respectively. Thirty-one percent of ICU admitted patients had CRS grade 3 or above, and 61% had ICANS grade 3 or above. All 4 patients with B-ALL experienced grade 3 or above CRS and required ICU admission. Only 1 of the 37 patients (2.7%) patients died from CRS. Fifty-six percent of ICU patients experienced disease progression during follow-up, compared to 33% of non-ICU patients (OR 2.50, p = 0.20, 95% CI 0.55-12.11). Over a median follow up of 399 days, 56% of ICU patients died compared to 14% of non-ICU patients (OR 7.23, p = 0.01, 95% CI 1.32-54.27). The majority of deaths (58%) were due to disease progression.
Conclusions:A significant number of patients who receive CD-19 direct CAR T-cells require ICU admission. Patients requiring ICU admission after CAR T-cell have a worse outcome and overall survival, compared to non-ICU patients. The mortality rate of ICU admitted patients is primarily driven by death from disease.

Disclosures
Tzachanis: MS:Research Funding;EUSA Pharma:Consultancy;Fate:Research Funding;Genetech:Research Funding;Gilead Sciences:Consultancy, Research Funding, Speakers Bureau;Incyte:Research Funding;Jazz Pharmaceuticals:Consultancy;Kyowa Kirin:Consultancy;Magenta:Consultancy;Takeda:Consultancy, Speakers Bureau.Goodman:Seattle Genetics:Consultancy;EUSA Pharma:Consultancy.