Ames negative; clastogenic (micronucleus) in vitro in mouse lymphoma cells and in vivo in rat bone marrow
“RIS was negative for mutagenicity in an in vitro Ames test but positive for clastogenicity (micronucleus (MN) formation) in vitro in mouse lymphoma cells and in vivo in a combined bone marrow micronucleus and comet assay in rat.”
✓ VerifiedFDA pharmacology/toxicology review, p. 8Source ↗
Carcinogenicity
6-month rasH2 mouse: no tumors up to 9 mg/kg/day
“A 6-month carcinogenicity study in Tg.rasH2 mice showed no tumorigenic effects at oral doses up to 9 mg/kg/day”
✓ VerifiedFDA pharmacology/toxicology review, p. 8Source ↗
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
Rabbit EFD: embryofetal death and hydrocephaly at maternally toxic 12 mg/kg
“Embryofetal mortality (increased number of late resorptions) and increased incidences of fetal malformations (hydrocephaly) and variations were seen in the rabbit embryofetal development study at the HD (12 mg/kg), which was also maternally toxic.”
✓ VerifiedFDA pharmacology/toxicology review, p. 8Source ↗
Safety pharmacology
No significant hERG inhibition; no hemodynamic or ECG effects in monkeys at single doses up to 7.5 mg/kg
“In safety pharmacology studies, RIS concentrations up to 5 mM (said to correspond to ~18000 ng/mL total plasma concentration in human) produced no significant reduction in the outward K+ current in CHO cells expressing recombinant hERG K+ channels. In cynomolgus monkeys, administration of single oral doses up to 7.5 mg/kg had no effects on hemodynamic or ECG parameters at up to 24 hours postdose.”
✓ VerifiedFDA pharmacology/toxicology review, p. 5Source ↗
Genotox: Ames
Negative
“RIS was negative for mutagenicity in an in vitro Ames test but positive for clastogenicity (micronucleus (MN) formation) in vitro in mouse lymphoma cells”
✓ VerifiedFDA pharmacology/toxicology review, p. 8Source ↗
Genotox: in vitro mammalian
Micronucleus in mouse lymphoma cells: positive (clastogenic)
“RIS was negative for mutagenicity in an in vitro Ames test but positive for clastogenicity (micronucleus (MN) formation) in vitro in mouse lymphoma cells”
✓ VerifiedFDA pharmacology/toxicology review, p. 8Source ↗
Genotox: in vivo
Rat bone marrow micronucleus + comet assay: positive (micronucleus formation)
“positive for clastogenicity (micronucleus (MN) formation) in vitro in mouse lymphoma cells and in vivo in a combined bone marrow micronucleus and comet assay in rat.”
✓ VerifiedFDA pharmacology/toxicology review, p. 8Source ↗
Carcinogenicity model
6-month Tg rasH2 mouse: no tumors up to 9 mg/kg/day
“A 6-month carcinogenicity study in Tg.rasH2 mice showed no tumorigenic effects at oral doses up to 9 mg/kg/day, which was associated with exposures (AUC) of 15600 and 11800 ng.hr/mL in males and females, respectively.”
✓ VerifiedFDA pharmacology/toxicology review, p. 8Source ↗
Carcinogenicity timing
rasH2 mouse study completed; 2-year rat study ongoing at approval as a post-approval commitment
“A two-year carcinogenicity study in rats is planned to be conducted post-approval. This is acceptable and in agreement with feedback received from CHMP and PDCO. Reference to the ongoing carcinogenicity study in rats is presented in SmPC section 5.3.”
No significant hERG current reduction up to 5 mM (~18000 ng/mL human plasma equivalent)
“In safety pharmacology studies, RIS concentrations up to 5 mM (said to correspond to ~18000 ng/mL total plasma concentration in human) produced no significant reduction in the outward K+ current in CHO cells expressing recombinant hERG K+ channels.”
✓ VerifiedFDA pharmacology/toxicology review, p. 5Source ↗
Not genotoxic overall: Ames negative; in vitro chromosome aberration positive without (not with) metabolic activation; rat micronucleus and comet negative