Abstract Anaphylactic reactions at the time of chimeric antigen receptor T (CAR‐T) cell infusion are adverse events that have not been reported in pivotal clinical trials or in real‐world series. We report the case of patient with severe anaphylaxis with cardiac arrest after tisagenlecleucel injection for Diffuse Large B cell Lymphoma, who recovered after resuscitation and intensive care treatment; we also conducted a Food and Drug Administration Adverse Event Reporting System database analysis and found several cases of severe anaphlyaxis after CAR‐T cell injection. Although not reported in pivotal CAR‐T cell studies, anaphylaxis can occur after CAR‐T cell injection, highlighting the need to include anaphylaxis as a possible side effect in future studies.
