“There were no pro-inflammatory T cell responses (IFN-γ) to the AAV2 capsid, except for one NHP previously exposed to AAV2 vector that developed a CD4+ T cell response.”
✓ VerifiedFDA pharmacology/toxicology review, p. 3Source ↗
Biodistribution & persistence
Vector DNA mainly in intraocular fluids; low in optic nerve, spleen, liver; none in gonads; shedding not studied in animals
“The highest levels of vector DNA were detected primarily in the intraocular fluids (anterior chamber fluid and vitreous) of vector-injected eyes.”
✓ VerifiedFDA pharmacology/toxicology review, p. 2Source ↗
Modality-specific risk
Immune-mediated ocular inflammation and retinal degeneration at high vector dose; surgical procedure trauma; re-administration immunity
“Subretinal injection of 1.5 x 1012 vg/eye of a precursor AAV2-hRPE65v2 vector product in normal-sighted dogs resulted in ocular inflammation and retinal degeneration histologically in regions exposed to the vector.”
✓ VerifiedFDA pharmacology/toxicology review, p. 2Source ↗
Anti-drug antibodies: animals
Anti-AAV2 capsid antibodies in dogs and AAV2-pre-exposed NHPs (not naive NHPs); transient anti-RPE65 antibodies in isolated cases
“Antibodies to the AAV2 capsid were present in the anterior chamber fluid and/or serum of normal-sighted and RPE65 mutant dogs. Antibodies to the AAV2 capsid were not detected in naïve NHPs, but were detected in NHPs previously exposed to AAV2 vector.”
✓ VerifiedFDA pharmacology/toxicology review, p. 3Source ↗
Anti-drug antibodies: patients
Immune reactions mild; no clinically significant cytotoxic T-cell response to AAV2 or RPE65 (with corticosteroid cover)
“No subject had a clinically significant cytotoxic T-cell response to either AAV2 or RPE65. Subjects received systemic corticosteroids before and after subretinal injection of LUXTURNA to each eye.”