NSG mice: distribution to lungs, blood, bone marrow, liver, spleen; biphasic peaks Days 2/11 blood, 8/15 tissues
“A biphasic peak expansion of bb2121 cells was observed on Days 2 and 11 in the peripheral blood and Days 8 and 15 in analyzed tissues in tumor-bearing mice.”
✓ VerifiedFDA pharmacology/toxicology review, p. 2Source ↗
Modality-specific risk
Insertional mutagenesis from lentiviral integration; tumorigenic transformation
“A tailored safety evaluation was conducted which focused on the investigation of the risk of insertional mutagenesis due to lentiviral integration in the genome of ide-cel CAR T cells”
Not reported in the public reviews. Reviewers summarise selectively, so this usually means it wasn't discussed publicly, not that it wasn't studied.
Anti-drug antibodies: patients
Treatment-induced anti-CAR antibodies 53%; pre-infusion 2.6%; no clinically significant impact
“In the clinical studies, 2.6% of patients (9/349) tested positive for pre-infusion anti-CAR antibodies and treatment-induced anti-CAR antibodies were detected in 53% (186/349) of the patients.”