An in-depth analysis of tissue biopsies from patients with multiple myeloma and CAR T cell therapy-associated immune-related adverse events (CirAEs) after treatment with commercial BCMA-targeted CAR T cell therapy shows that CD4+ CAR T cells mediate off-tumor toxicities and that high CD4:CD8 ratio at apheresis, robust early CAR T cell expansion, ICANS and ciltacabtagene autoleuce treatment are independently associated with the development of CirAEs.
- Matthew Ho
- Luca Paruzzo
- Joseph A. Fraietta