1994. Infections following Chimeric Antigen Receptor (CAR) – T cell Therapy: 2018-2022

Abstract Background Chimeric Antigen Receptor (CAR) T-cell therapy is an emerging therapeutic modality for relapsing and refractory haematological malignancies. We describe the infectious complications following CAR T-cell therapy. Methods This is a retrospective analysis of data on patients who received CAR-T cell therapy between April 2018 and December 2022 at Karmanos Cancer Institute, Detroit, Michigan. Patients’ data were collected up to their last known clinic or inpatient follow-up visit. An infectious episode was defined as any microbiologically proven or documented infection. Statistical analysis was performed using SPSS software version 28.0. Results Seventy-six patients received therapy with FDA-approved CAR-T cell products. Thirty-three patients (43.4%) had at least one infection with a range of 1 to 4 infectious episodes per patient. There were 61 infectious episodes during a median follow-up of 184 (96-340) days. The median duration for the onset of infection was 59 (22-209) days. Bacterial and viral infections occurred in 42.6% and 41% of the infectious episodes respectively. COVID-19 was the most common infectious complication (14.8%). Time-to-event analysis showed that most of the infections occurred within the first 100 days (Figure 2). Empirical antibiotic use in Cytokine Release Syndrome (CRS)/ Immune effector Cell-Associated Neurotoxicity Syndrome (ICANS) in the absence of documented infection was reported in 85.7% of patients. Clostridioides difficile (C.difficile) accounted for 11.5% of all infections. Out of 6 patients with C.difficile infection 5 patients had CRS and antibiotic use. There were four documented deaths during the study period. Two deaths occurred in patients who had an infection. Conclusion The mortality rate among patients who had an infection was 6.5%. Most of the infections occurred within the first 100 days. COVID-19 and C. difficile infection were the most common infections following CAR-T cell therapy. The rate of C. difficile infection was high in patients with CRS receiving empiric antibiotics in the absence of any documented infection, thus providing an opportunity for antibiotic stewardship in this population. Disclosures All Authors: No reported disclosures