CarcinogenicityAcceptedBeyond the letter
No rodent carcinogenicity studies for a chronically used intranasal drug
Why: Intermittent dosing, no pharmacology- or toxicology-based concern, technical challenges of long-term intranasal rodent dosing · Pharmacology or kinetics · Other reason
“Considering the intermittent clinical dosing and exposure profile, lack of obvious pharmacology- and toxicology-based concerns, and the technical challenges of conducting long-term studies in rodents with the intended nasal route of administration, the Division agreed that rodent carcinogenicity studies are not warranted for the proposed clinical indication and dosing regimen”
✓ VerifiedFDA integrated review, p. 132Source ↗ SpeciesAcceptedBeyond the letter
Chronic toxicity in one species (cynomolgus monkey); no chronic rodent study
Why: Technical challenge of long-term intranasal dosing in rodents, rapid biotransformation, intermittent clinical treatment · Pharmacology or kinetics · Other reason
“Considering the technical challenge of long-term administration via intranasal route in rodents, the rapid biotransformation of etripamil, and the intended intermittent clinical treatment (potentially 36 dosing occasions per year over a lifetime), a chronic toxicity study in one species (cynomolgus monkeys) was considered acceptable.”
✓ VerifiedFDA integrated review, p. 121Source ↗ DARTVerdict not stated
All pivotal reproductive toxicity studies dosed intravenously instead of by the clinical intranasal route
Why: Achieve adequate exposures during the critical organogenesis period · Pharmacology or kinetics
“The Applicant has conducted all the pivotal reproductive toxicity studies (embryo-fetal development in rats and rabbits, fertility and early embryonic development, and pre- and postnatal development in rats) via intravenous route of administration QD, as opposed to the intranasal route to achieve adequate exposures during critical organogenesis period.”
✓ VerifiedFDA integrated review, p. 132Source ↗ Safety marginVerdict not stated
Embryo-fetal studies: high doses limited by maternal toxicity, giving exposure multiples below 1 at the MRHD
Why: High doses limited by maternal toxicities (mortalities, clinical signs) in rats and rabbits
“Although no fetal toxicities were noted at any dose levels in both rat and rabbit embryo-fetal development studies, the high doses tested were limited due to maternal toxicities (mortalities, transient clinical signs) observed in both rats and rabbits. This resulted in low exposure multiples (<1) when compared to the exposure at the MRHD (see Table 53 below) given that the high doses were limited.”
✓ VerifiedFDA integrated review, p. 132Source ↗