Impurity or metaboliteVerdict not stated
Major human metabolites M2, M3 and M13 not formed in rodents; given SC as a metabolite cocktail in mouse carcinogenicity and rat pre/postnatal studies
Why: Achieve at least 1X human metabolite exposure in rodent studies · Pharmacology or kinetics
“The metabolites were not detected in mouse, rat, or dog plasma, and were administered SC as a metabolite cocktail to mice and rats in a mouse carcinogenicity study and rat pre-and post-natal development study to achieve at least 1X human exposure.”
✓ VerifiedFDA integrated review, p. 244Source ↗ GenotoxicityAcceptedBeyond the letter
Uncertain genotoxic potential of major metabolite M13 after mouse lymphoma and initial mouse liver comet assays
Why: Division concluded M13 was not genotoxic
“Genotoxicity studies paused based on the uncertainty about the genotoxic potential of the M13 metabolite of GSK 1278863 following the results of mouse lymphoma assay and the initial mouse liver comet assay”
✓ VerifiedFDA integrated review, p. 230Source ↗ “The Division concluded that the M13 metabolite was not genotoxic and agreed with the Sponsor to re-initiate clinical trials of GSK 12788863”
✓ VerifiedFDA integrated review, p. 230Source ↗