Negative in Ames and additional mutagenicity tests and in the rat bone marrow/liver micronucleus assay
“Taletrectinib was not mutagenic in the in vitro bacterial reverse mutation (Ames) assay and additional mutagenicity tests. Taletrectinib was not clastogenic or aneugenic in the in vivo micronucleus study in rats in bone marrow and liver.”
Not conducted; not warranted for the proposed indication
“Carcinogenicity studies have not been conducted with taletrectinib and are not warranted for the proposed indication.”
✓ VerifiedFDA multi-discipline review, p. 46Source ↗
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
Rat and rabbit EFD: embryo-fetal mortality and structural abnormalities at or below human exposure
“In animal reproduction studies, oral administration of taletrectinib to pregnant rats and rabbits during the period of organogenesis resulted in embryo-fetal mortalities and structural abnormalities at exposures that were below or equal to the human exposure based on AUC at the recommended dose”
hERG IC50 0.98 µM, hNav1.5 IC50 0.83 µM; no ECG or QTc effects in telemetered monkeys up to 100 mg/kg/day
“In vitro, taletrectinib inhibited hERG currents and hNav1.5 with IC50 values of 0.98 µM and 0.83 µM, respectively, indicating a potential effect on QT prolongation. However, in the telemetered monkey cardiovascular study, there were no effects on any electrocardiogram (ECG) parameters, including QTc at the highest non-severely toxic dose (HNSTD) of 100 mg/kg/day.”
✓ VerifiedFDA multi-discipline review, p. 55Source ↗
Genotox: Ames
Negative (Ames assays)
“Taletrectinib was negative for mutagenicity in in vitro bacterial reverse mutation (Ames) assays and additional mutagenicity tests, including 2 mammalian cell gene mutation assays and one in vivo gene mutation assay in rats.”
✓ VerifiedFDA multi-discipline review, p. 45Source ↗
Genotox: in vitro mammalian
In vitro chromosome aberration study: positive (structural and numerical aberrations)
“In an in vitro chromosome aberration study, taletrectinib was predicted to have the potential to induce structural and numerical aberrations.”
✓ VerifiedFDA multi-discipline review, p. 78Source ↗
Genotox: in vivo
Rat micronucleus (liver and bone marrow): negative up to 300 mg/kg
“Taletrectinib was not clastogenic or aneugenic in the in vivo micronucleus study in rats in liver or bone marrow when administered orally up to 300 mg/kg.”
✓ VerifiedFDA multi-discipline review, p. 45Source ↗
Carcinogenicity model
Not conducted (advanced cancer indication)
“Carcinogenicity studies are not planned as taletrectinib is intended to treat patients with advanced cancer.”
✓ VerifiedFDA multi-discipline review, p. 84Source ↗
Carcinogenicity timing
Not required for the advanced ROS1-positive NSCLC indication
“FDA agrees that carcinogenicity studies are not warranted for the current indication of adult patients with locally advanced or metastatic ROS1-positive non-small cell lung cancer (NSCLC).”
✓ VerifiedFDA multi-discipline review, p. 84Source ↗
hERG / QT
hERG IC50 0.98 µM (potential QT effect); no ECG/QTc effects in telemetered monkeys at 100 mg/kg/day
“In vitro, taletrectinib inhibited hERG currents and hNav1.5 with IC50 values of 0.98 µM and 0.83 µM, respectively, indicating a potential effect on QT prolongation. However, in the telemetered monkey cardiovascular study, there were no effects on any electrocardiogram (ECG) parameters, including QTc at the highest non-severely toxic dose (HNSTD) of 100 mg/kg/day.”
✓ VerifiedFDA multi-discipline review, p. 55Source ↗
Not genotoxic overall: Ames negative; in vitro chromosome aberration positive without (not with) metabolic activation; rat micronucleus and comet negative