Safety marginAccepted with a conditionBeyond the letter
No exposure margin for teratogenicity: rat and rabbit embryo-fetal NOAELs at exposures similar to or below the clinical dose
Why: Label carries a Warning for embryo-fetal toxicity based on nonclinical data
“Upadacitinib is a potent teratogen in rats and rabbits, with NOAELs in these studies associated with exposes similar to or less than the proposed clinical dose. While other approved JAK inhibitors are also teratogenic, the review team expressed concern regarding the lack of exposure margins between the embryo-fetal toxicity and the proposed clinical dose level.”
✓ VerifiedFDA pharmacology/toxicology review, p. 6Source ↗ “Based on discussion among the nonclinical review team, clinical review team (Dr. Keith Hull and Dr. Rachel Glaser), DPARP management, ODE2 Pharmacology-Toxicology Associate Director Dr. Timothy McGovern, and the Division of Pediatric and Maternal Health, a consensus was reached that the UPA label should include a Warning for embryo-fetal toxicity based on nonclinical data.”
✓ VerifiedFDA pharmacology/toxicology review, p. 6Source ↗ Impurity or metaboliteAccepted
Major human metabolite M4 (glucuronide) not covered in rat or dog; no additional safety testing
Why: Glucuronide formed after monooxidation not a safety concern, consistent with ICH M3(R) Questions and Answers · Within the guideline
“The major metabolite of UPA in human plasma (i.e., M4, 13%) following a single oral dose is not covered by equivalent amounts detected in either dog (i.e., M4, 0.9%) or rat (i.e., M4, not detected) ADME studies.”
✓ VerifiedFDA pharmacology/toxicology review, p. 52Source ↗ “However, as the M4 human metabolite is a product of monooxidation followed by glucuronidation it was not considered a safety concern, consistent with ICH M3(R) Questions & Answers (June 2011).”
✓ VerifiedFDA pharmacology/toxicology review, p. 52Source ↗ GenotoxicityAcceptedBeyond the letter
Positive for numerical chromosome aberrations in vitro in human lymphocytes; negative for structural aberrations and in vivo micronucleus
Why: No structural chromosome breakage and negative in vivo micronucleus assay reassure against aneuploidy · Weight of evidence
“In the in vitro mammalian chromosome aberration test in human peripheral blood lymphocytes, upadacitinib was found negative for induction of structural chromosome aberrations but positive for induction of numerical chromosome aberration.”
✓ VerifiedEMA assessment report, p. 30Source ↗ “Since no effect was observed on the structural chromosome breakage and the in vivo micronucleus assay was found negative, this is considered sufficient reassurance of lack of potential for aneuploidy induction.”
✓ VerifiedEMA assessment report, p. 30Source ↗