Do CARs need a driver's license? Adoptive cell therapy with chimeric antigen receptor-redirected T cells caused serious adverse events

Adoptive transfer of genetically retargeted T cells provides promise in the therapy of malignant diseases; two severe adverse events, however, due to "on-targeted" activation of modified T cells occurred in recent trials. We here discuss the challenge to balance targeted anti-tumor responses whilst avoiding destruction of healthy tissues and the need of continued and carefully designed pre-clinical and clinical evaluations