Outpatient Administration of CAR T-cell Therapies Using a Strategy of No Remote Monitoring and Early CRS Intervention

Recent studies demonstrating the feasibility of outpatient chimeric antigen receptor (CAR)-modified T-cell therapy administration are either restricted to CARs with 41BB costimulatory domains or use intensive at-home monitoring. We report outcomes of outpatient administration of all commercially available CD19- and B-cell maturation antigen (BCMA)-directed CAR T-cell therapy using a strategy of no remote at-home monitoring and an early cytokine release syndrome (CRS) intervention strategy. Patients with hematologic malignancies who received CAR T-cell therapy in the outpatient setting during 2022 to 2023 were included. Patients were seen daily in the cancer center day hospital for the first 7 to 10 days and then twice weekly through day 30. The primary end point was to determine 3-, 7-, and 30-day post-CAR T-cell infusion hospitalizations. Early CRS intervention involved administering tocilizumab as an outpatient for grade ≥1 CRS. Fifty-eight patients received outpatient CAR T-cell infusion (33 myeloma, 24 lymphoma, and 1 acute lymphoblastic leukemia). Of these, 17 (41%), 16 (38%), and 9 patients (21%) were admitted between days 0 to 3, 4 to 7, and 8 to 30 after CAR T-cell infusion, respectively. The most common reason for admission was CAR T-cell-related toxicities (33/42). Hospitalization was prevented in 15 of 35 patients who received tocilizumab for CRS as an outpatient. The nonrelapse mortality rates were 1.7% at 1 month and 3.4% at 6 months. In conclusion, we demonstrate that the administration of commercial CAR T-cell therapies in an outpatient setting is safe and feasible without intensive remote monitoring using an early CRS intervention strategy.