Safety marginAcceptedBeyond the letter
Safety margins below 1 at all dose levels in rat and dog toxicity studies versus human exposure at 125 mg QD
Why: Greater sensitivity of nonclinical species to FGFR inhibition; mechanism-related findings monitorable and manageable in patients · Pharmacology or kinetics · Serious disease
“The safety margins at all dose levels was <1 based on a comparison of Cmax or AUC values in rat and dog toxicity studies to the human exposure (6284 ng*hr/mL; Cycle 1, Day 15) at the recommended dose of 125 mg QD, reflecting the greater sensitivity of the nonclinical species in the toxicology program to the pharmacologic effects (ie, inhibition of FGFR1‐3) of infigratinib.”
✓ VerifiedFDA multi-discipline review, p. 51Source ↗ “The overall toxicity profile of infigratinib includes mechanism‐related findings that can be monitored and/or are considered clinically manageable in the intended patient population. The FDA’s Assessment: FDA generally agrees with the Applicant’s position.”
✓ VerifiedFDA multi-discipline review, p. 51Source ↗ Safety marginVerdict not stated
Rat developmental toxicity NOAEL could not be determined (<1 mg/kg/day)
“The NOAEL for developmental toxicity could not be determined (<1 mg/kg/day).”
✓ VerifiedFDA multi-discipline review, p. 67Source ↗