Juvenile toxAccepted with a conditionBeyond the letter
Juvenile rat toxicity and neonatal neurotoxicity studies deferred to postmarketing requirements
Why: Needed only before clinical studies in pediatric patients from birth to under 3 years · Other reason
“Conduct a juvenile animal study in rats to support the initiation of clinical studies in pediatric patients from birth to less than 3 years of age.”
✓ VerifiedFDA multi-discipline review, p. 203Source ↗ “From a nonclinical pharmacology toxicology perspective, NDA 220482 may be approved with Pediatric Research Equity Act (PREA) postmarketing requirements.”
✓ VerifiedFDA multi-discipline review, p. 35Source ↗ Impurity or metaboliteAccepted
No safety characterization of the major human O-glucuronide metabolite M4, poorly covered in rats
Why: Non-acyl glucuronide conjugate, pharmacologically inactive · Within the guideline · Pharmacology or kinetics
“M4 is a non-acyl-glucuronic acid metabolite confirmed by the CMC Reviewer and demonstrated to not be pharmacologically active. No additional safety characterization was conducted for M4, which was deemed acceptable by the Division during drug development.”
✓ VerifiedFDA multi-discipline review, p. 38Source ↗ OtherAcceptedBeyond the letter
Repeat-dose general toxicology studies dosed every other day rather than daily
“The Division acknowledged the Applicant’s justification for dosing animals every other day in the repeat-dose general toxicology studies.”
✓ VerifiedFDA multi-discipline review, p. 224Source ↗ OtherCriticised but acceptedBeyond the letter
Local tolerance histopathology done on Day 3 or 4 after dosing; no acute local assessment
Why: Clinical data can be leveraged for the local safety assessment · Human data
“Note that the assessment of histopathology was conducted on Day 3 or Day 4 after the final dose; therefore, the acute assessment of the local effects was not adequate, although clinical observation on the dosing site was conducted at several more acute time points after dosing.”
✓ VerifiedFDA multi-discipline review, p. 203Source ↗ “The lack of acute local histopathological assessment of the dosing site is not considered an approval issue, given that clinical data can be leveraged for the local safety assessment.”
✓ VerifiedFDA multi-discipline review, p. 203Source ↗