Negative in Ames, in vitro chromosome aberration (human lymphocytes) and rat bone marrow micronucleus assays
“Pexidartinib was not mutagenic in the in vitro bacterial reverse mutation (Ames) test or clastogenic in either the in vitro chromosomal aberrations assay in peripheral human lymphocytes or the in vivo bone marrow micronucleus assay in rats.”
✓ VerifiedFDA multi-discipline review, p. 41Source ↗
Carcinogenicity
2-year rat and 26-week transgenic mouse: negative
“The Applicant also conducted a two-year (104-week) carcinogenicity study in rats and a 26-week carcinogenicity study in transgenic mice. Pexidartinib was negative for carcinogenicity in these studies.”
✓ VerifiedFDA multi-discipline review, p. 41Source ↗
Reproductive & developmental
EFD: malformations, post-implantation loss and abortion at maternal exposures about equal to human exposure
“Oral administration of pexidartinib to pregnant animals during the period of organogenesis resulted in malformations, post-implantation loss, and abortion at maternal exposures that were approximately equal to the human exposure at the recommended dose (see Data ) .”
No CNS or respiratory effects up to 200 mg/kg; hERG IC50 0.7 µM but no QTc or other ECG effects in vivo
“There were no pexidartinib-related adverse effects on the central nervous system or respiratory function following a single dose up to 200 mg/kg. Pexidartinib inhibited the hERG potassium channel with an IC50=0.7 μM, suggesting some potential for QTc prolongation; however, there were no effects on QTc or other electrocardiogram parameters in in vivo animal studies”
✓ VerifiedFDA multi-discipline review, p. 39Source ↗
Not genotoxic overall: Ames negative; in vitro chromosome aberration positive without (not with) metabolic activation; rat micronucleus and comet negative