Abstract: Objective To analyze the adverse effects (AEs) of CD19 chimeric antigen receptor T (CAR⁃T) cell drugs on the market , so as to provide evidence for clinical treatment. Methods The United States Food and Drug Administration's adverse event reporting system (FAERS) database was used to obtain the baseline data and the AE results of four marketed CD19 CAR⁃T drugs from the first quarter of 2017 to the fourth quarter of 2023 after data retrieval, screening, deduplication, collation and analysis. The reporting odds ratio (ROR) and proportional ADR reporting ratio (PRR) were used to analyze and compare the AE results. Results A total of 5, 335 reports of 4 marketed CD19 CAR⁃T drugs included Axicabtagene ciloleucel (Axi⁃cel）, Tisagenleucel (Tisa⁃cel）, Brexucabtagene autoleucel (Brexu⁃cel) and Lisocabtagene maraleucel (Liso⁃cel) were obtained from the FAERS database. The proportion of the four CD19 CAR⁃T drugs in males was higher than that in females; the age distribution was above 18 years old; and the body weight was mostly concentrated in 50-100 kg. CD19 CAR⁃T drugs were involved in 23 types of system organ classification (SOC）, mainly focusing on neurological diseases and immune system diseases, among which cytokine release syndrome (CRS) and immune effector cell⁃associated neurotoxicity syndrome (ICANS) were the most common. In addition, some AEs not listed in the label were also found in this study, such as myelodysplastic syndromes (MDS）, acute kidney injury (AKI）, and sepsis. Conclusions In clinical practice, attention should also be paid to the possible unlisted AEs, such as MDS, AKI and sepsis, in addition to the AEs mentioned in the drug label. 

Key words: CD19 CAR-T drugs, Adverse effects, FAERS database, Data mining