CarcinogenicityVerdict not stated
No carcinogenicity studies
Why: Limited duration of intended use for VVC · Within the guideline
“Carcinogenicity studies were not performed for ibrexafungerp due to the limited duration of its intended use for the treatment of VVC.”
✓ VerifiedFDA multi-discipline review, p. 43Source ↗ Safety marginAccepted with a conditionBeyond the letter
Rabbit embryo-fetal NOAEL only about 2-fold, LOAEL about 5-fold, clinical AUC with severe malformations
Why: Contraindication in pregnancy, pregnancy verification and contraception advice in labeling
“The plasma AUC values associated with the No-Observed-Adverse-Effect Level (NOAEL) and Lowest-Observed-Adverse-Effect Level (LOAEL) doses in rabbits are approximately 2- and 5-times respectively the plasma AUC exposures expected for fed patients.”
✓ VerifiedFDA multi-discipline review, p. 43Source ↗ “A contraindication for use in pregnancy will be included in the labeling. Providers will be advised to verify pregnancy status for females of reproductive potential prior to oral ibrexafungerp treatment and recommend use of effective contraception during treatment and for 4 days after the last dose.”
✓ VerifiedFDA multi-discipline review, p. 153Source ↗ Safety pharmacologyAcceptedBeyond the letter
hERG IC50 only 1.4-fold the clinical Cmax
Why: No QTc prolongation at high exposures in a clinical study · Human data
“Results from an in vitro hERG assay indicated that the ibrexafungerp IC50 for hERG inhibition was 1.4-fold higher than the plasma Cmax value associated with the recommended clinical dose of 600 mg/day ibrexafungerp in fed patients.”
✓ VerifiedFDA multi-discipline review, p. 42Source ↗ “A potential for QTc prolongation revealed in an assessment of ibrexafungerp inhibition of hERG activity is not expected to be a clinical concern based on the lack of QTc prolongation with high ibrexafungerp exposures in a Phase 1 study.”
✓ VerifiedFDA multi-discipline review, p. 44Source ↗