CarcinogenicityAcceptedBeyond the letter
No traditional carcinogenicity studies; insertional mutagenesis assessed by in vitro immortalization assay and integration site analysis
Why: Acceptable based on the product type · Other reason
“Carcinogenicity Studies: No traditional carcinogenicity studies were conducted with lovo-cel which is acceptable based on the product type.”
✓ VerifiedFDA pharmacology/toxicology review, p. 26Source ↗ DARTAcceptedBeyond the letter
No developmental and reproductive toxicity studies
Why: No adverse findings in reproductive tissues of mice; not warranted given product characteristics and safety profile · Weight of evidence · Other reason
“Developmental and Reproductive Toxicology Studies: Per the applicant, developmental and reproductive toxicology studies were not conducted because there were no adverse findings in the male and female reproductive tissues of mice administered mBMCs transduced with BB305 LVV”
✓ VerifiedFDA pharmacology/toxicology review, p. 22Source ↗ “Carcinogenicity and developmental and reproductive toxicity studies were not conducted with LYFGENIA™. These studies are not warranted based on the product characteristics and safety profile.”
✓ VerifiedFDA pharmacology/toxicology review, p. 3Source ↗ Efficacy modelVerdict not stated
Proof-of-concept in SCD mice used a related vector (βA-T87Q LVV) encoding the same transgene, not BB305
Why: Related vector encodes the same transgene
“In vivo POC studies were also conducted using transgenic mouse models of SCD, where murine bone marrow cells (mBMCs) were transduced with the βA-T87Q LVV, a related vector encoding the same transgene, and showed expression of βA-T87Q and correction of the sickling phenotype through 3 months post-transplantation.”
✓ VerifiedFDA summary basis for approval, p. 11Source ↗