Dog study 20099163 at 10 mg/kg/day: 7.4-fold human AUC (6.0-fold Cmax); axonal dystrophy still seen at this dose
“According to the applicant, the margins between the clinical exposure and the exposures in the lowest dose group at which ritlecitinib-related axonal dystrophies were observed (rostral cerebellar vermis at 10 mg/kg/day, study 20099163) are only 6.0-fold in terms of Cmax and 7.4-fold in terms of AUC24.”
NOAEL 5 mg/kg/day: brainstem findings at ≥20 mg/kg/day; immunosuppression and hearing effects at high dose
“The NOAEL was 5 mg/kg/day based on microscopic findings in the brainstem at doses ≥20 mg/kg/day and adverse immunosuppressive effects and effects on hearing at the HD.”
✓ VerifiedFDA multi-discipline review, p. 39Source ↗