Fever Characteristics and Impact on Safety and Efficacy of Chimeric Antigen Receptor T-Cell Therapy.

Background: Fever is a hallmark symptom of cytokine release syndrome (CRS) after chimeric antigen receptor (CAR) T-cell therapy. Fever characteristics and the impact of fever on safety and efficacy post CAR T are not well understood. We sought to explore the impact of fever and its characteristics on safety and efficacy post CAR T-cell therapy.

Patients And Methods: We reviewed 40 patients with various hematologic malignancies (non-Hodgkin lymphoma, acute lymphoblastic leukemia, multiple myeloma) treated with CAR T-cell therapy between March 2019 and March 2022. We evaluated all patients who developed fever after CAR T infusion and analyzed the association of fever with toxicity (CRS and neurotoxicity) and efficacy (overall response (ORR) and complete response (CR) at day +90 post CAR T infusion). Fever was defined as per Lee criteria (equal to or greater than 38°C). CRS and immune-effector cell associated neurotoxicity syndrome (ICANS) were graded using American Society for Transplantation and Cellular Therapy grading system.

Results: Fever occurred in 75% (30/40) of patients. Rates of all grade and grade 3+ CRS and ICANS were 75%, 2%, 33% and 10%, respectively. Fever occurred within 24 and 72 hours after CAR T infusion in 40% and 53% of patients, respectively. Fifty percent of patients received tocilizumab (toci) for CRS. After the first dose of toci, fever recurred in 38% of the patients, of which 67% had recurrence within 24 hours. Day +90 CR rates were 43% and 10% in patients with and without fever, respectively (Table 3).

Conclusion: While fever is common after CAR T-cell therapy, early-onset and higher magnitude do not appear to affect safety or efficacy of CAR T. Absence of fever may affect response to CAR T.