Patients with aggressive B‐cell lymphoma receiving CAR T‐cell therapy have a low rate of severe infections despite lack of universal antibacterial and antifungal prophylaxis

Abstract Objectives Our aim was to describe the frequency and severity of infectious complications after chimeric antigen receptor (CAR) T‐cell therapy in patients with large B‐cell lymphoma (LBCL). Methods We retrospectively reviewed clinical records of LBCL patients treated with CD19‐targeted CAR T‐cell therapy from July/2018 to December/2021 at our institution, and identified all infectious episodes from CAR T‐cell infusion until disease progression, death or last follow‐up. Results Overall, 137 patients were included. Thirty six percent had received ≥3 previous lines of therapy and 26% an autologous hematopoietic cell transplantation (auto‐HCT). Cytokine release syndrome occurred in 87 (64%) patients. Antibacterial prophylaxis was not used in any patient; only 38% received antifungal prophylaxis. Sixty three infectious events were observed in 41 (30%) patients. Fifty two (83%) of the infectious events had at least one pathogen identified (bacteria n = 38, virus n = 11, and fungi n = 3). Most of the infectious events occurred during hospitalization for CAR‐T treatment. Infection‐related mortality was observed in two patients. Independent risk factors for infection included male gender, previous auto‐HCT, ≥3 lines of treatment and pre‐lymphodepletion neutropenia. Conclusions Infections after CAR T‐cell therapy in patients with lymphoma are frequent but generally not severe. A conservative and tailored antimicrobial prophylaxis seems to be a safe approach.