OtherCriticised but acceptedBeyond the letter
Brain not adequately evaluated in pivotal dog toxicity studies despite rat brain mineralization; nonclinical deficiency in first-cycle Not Approvable letter
Why: Re-analysis of brain sections from the 26- and 52-week dog studies provided · Weight of evidence
“The nonclinical deficiency was an inadequate evaluation of brain in the pivotal toxicity studies in dog, a concern raised by the finding of brain mineralization in rat.”
✓ VerifiedFDA pharmacology/toxicology review, p. 2Source ↗ “The sponsor has adequately addressed the nonclinical deficiency included in the division’s February 25, 2008, letter by providing a reanalysis of brain sections from the 26- and 52-week toxicity studies in dog.”
✓ VerifiedFDA pharmacology/toxicology review, p. 3Source ↗ GenotoxicityVerdict not stated
No valid mouse lymphoma assay: no compatible solvent, sufficiently high concentrations could not be tested
“The testing laboratory concluded that the mouse lymphoma assay was not appropriate for this compound as sufficiently high doses were not able to be tested.”
✓ VerifiedFDA pharmacology/toxicology review, p. 113Source ↗