CarcinogenicityAccepted with a conditionBeyond the letter
No genotoxicity or carcinogenicity/tumorigenicity studies; tumorigenicity risk to be assessed in a postmarketing study
Why: Limited vector distribution beyond the inner ear; no clinical evidence of carcinogenesis from recombinant AAV vectors · Class precedent · Pharmacology or kinetics · Human data
“No carcinogenicity studies have been conducted with DB-OTO. These were considered not warranted based on a review of the animal toxicology studies, data from biodistribution studies showing limited DB-OTO vector distribution beyond the local compartment of the inner ear, and a lack of clinical evidence of carcinogenesis attributable to recombinant AAV vectors.”
✓ VerifiedFDA pharmacology/toxicology review, p. 17Source ↗ “The potential risk of tumorigenicity will be assessed in a PMC study.”
✓ VerifiedFDA summary basis for approval, p. 20Source ↗ DARTAcceptedBeyond the letter
No developmental and reproductive toxicity studies
Why: Intracochlear route, limited systemic exposure, target patient population and no safety concerns in toxicology studies · Pharmacology or kinetics
“Developmental and reproductive toxicity, genotoxicity, and carcinogenicity studies were not conducted with DB-OTO. These studies were not warranted based on the intracochlear route of administration, limited systemic exposure, target patient population, and absence of safety concerns in the toxicology studies.”
✓ VerifiedFDA summary basis for approval, p. 15Source ↗ SpeciesVerdict not stated
Single-dose toxicology run in the Otof-Q828X deafness mouse model (plus cynomolgus monkey) rather than healthy rodents
“Single-dose toxicology studies were conducted in Otof-Q828X hom mice and cynomolgus monkeys.”
✓ VerifiedFDA pharmacology/toxicology review, p. 3Source ↗