GenotoxicityAcceptedBeyond the letter
Aneugenic in in vitro human lymphocyte micronucleus assays; in vivo rat micronucleus negative
Why: Human exposure below the rat no-effect level for aneugenicity; cancer patient population; FDA disputed the margin estimate · Serious disease · Pharmacology or kinetics
“Pirtobrutinib is an aneugenic genotoxicant; however, human exposure at 200 mg QD is 12-fold lower than the no effect level for this genotoxicity in rats. Thus, this is not a significant risk for cancer patients.”
✓ VerifiedFDA multi-discipline review, p. 52Source ↗ “The FDA agrees with the Applicant’s assessment, except for the estimation of the exposure margin.”
✓ VerifiedFDA multi-discipline review, p. 52Source ↗ Safety marginAccepted with a conditionBeyond the letter
Dog corneal lesions at 0.42-fold human AUC at the recommended dose
Why: Not a class toxicity and not a significant finding in humans; described in product information · Human data
“Corneal lesions were only observed in 2 dogs treated for 3 months. To date, this has not been identified as a drug class toxicity and has not been identified as a significant safety finding in the human population but is nevertheless described in the product information as it was observed at 0.42-fold human exposure (at the recommended dose of 200 mg based on AUC).”
✓ VerifiedEMA assessment report, p. 38Source ↗ Safety marginAccepted with a conditionBeyond the letter
Anti-KLH TDAR eliminated in male rats at 0.69-fold human AUC at the recommended dose
Why: Described in the product information
“Thus, the effect was considered adverse in male rats and is described in the product information as it was observed at 0.69-fold human exposure (at the recommended dose of 200 mg based on AUC).”
✓ VerifiedEMA assessment report, p. 38Source ↗