Defactinib: Ames and chromosome aberration negative; positive in vitro and in vivo rat micronucleus (aneugenic)
“Defactinib was not mutagenic in the bacterial reverse mutagenesis (Ames) assay and was not clastogenic in an in vitro Chinese hamster lung cell chromosome aberration assay. Defactinib was positive in the in vitro micronucleus assay through an aneugenic mechanism and in the in vivo rat bone marrow micronucleus assay.”
✓ VerifiedFDA multi-discipline review, p. 38Source ↗
Carcinogenicity
Not conducted (advanced cancer indication)
“The Applicant did not conduct carcinogenicity studies with avutometinib; it is also not warranted to support the marketing application of AVMAPKI FAKZYNJA CO-PACK for the proposed indication.”
✓ VerifiedFDA multi-discipline review, p. 36Source ↗
Instead of carcinogenicity
Not stated in public reviews
Not reported in the public reviews. Reviewers summarise selectively, so this usually means it wasn't discussed publicly, not that it wasn't studied.
Instead of genotoxicity
Not stated in public reviews
Not reported in the public reviews. Reviewers summarise selectively, so this usually means it wasn't discussed publicly, not that it wasn't studied.
DRG histopathology
Not stated in public reviews
Not reported in the public reviews. Reviewers summarise selectively, so this usually means it wasn't discussed publicly, not that it wasn't studied.
Reproductive & developmental
Not conducted for either drug; embryo-fetal toxicity assessed by weight of evidence
“The Applicant did not conduct any reproductive toxicology studies with avutometinib and defactinib.”
✓ VerifiedFDA multi-discipline review, p. 39Source ↗
Safety pharmacology
Avutometinib: weak hERG inhibitor, little or no QT risk
“In safety pharmacology studies, avutometinib was found to be a weak inhibitor of the hERG channel current. As such, the data suggests that avutometinib may pose little or no risk for QT interval effects.”
✓ VerifiedFDA multi-discipline review, p. 35Source ↗
Genotox: Ames
Defactinib: negative
“Defactinib was not mutagenic in the bacterial reverse mutagenesis (Ames) assay and was not clastogenic in an in vitro Chinese hamster lung cell chromosome aberration assay.”
✓ VerifiedFDA multi-discipline review, p. 38Source ↗
Genotox: in vitro mammalian
Defactinib: chromosome aberration (CHL) negative; in vitro micronucleus positive (aneugenic)
“Defactinib was not mutagenic in the bacterial reverse mutagenesis (Ames) assay and was not clastogenic in an in vitro Chinese hamster lung cell chromosome aberration assay. Defactinib was positive in the in vitro micronucleus assay through an aneugenic mechanism and in the in vivo rat bone marrow micronucleus assay.”
✓ VerifiedFDA multi-discipline review, p. 38Source ↗
Genotox: in vivo
Defactinib: rat bone marrow micronucleus positive
“Defactinib was positive in the in vitro micronucleus assay through an aneugenic mechanism and in the in vivo rat bone marrow micronucleus assay.”
✓ VerifiedFDA multi-discipline review, p. 38Source ↗
Carcinogenicity model
Not conducted (not warranted for the proposed indication)
“The Applicant did not conduct carcinogenicity studies with avutometinib; it is also not warranted to support the marketing application of AVMAPKI FAKZYNJA CO-PACK for the proposed indication.”
✓ VerifiedFDA multi-discipline review, p. 36Source ↗
Carcinogenicity timing
Not required for the advanced cancer indication
“The Applicant did not conduct carcinogenicity studies with avutometinib; it is also not warranted to support the marketing application of AVMAPKI FAKZYNJA CO-PACK for the proposed indication.”
✓ VerifiedFDA multi-discipline review, p. 36Source ↗
hERG / QT
Avutometinib: weak hERG inhibitor; little or no QT risk
“In safety pharmacology studies, avutometinib was found to be a weak inhibitor of the hERG channel current. As such, the data suggests that avutometinib may pose little or no risk for QT interval effects.”
✓ VerifiedFDA multi-discipline review, p. 35Source ↗
Not genotoxic overall: Ames negative; in vitro chromosome aberration positive without (not with) metabolic activation; rat micronucleus and comet negative