Negative in Ames, mammalian cell assays and mouse and rat micronucleus assays
“In genetic toxicology studies, siponimod was negative in the in vitro reverse mutation assay in bacterial cell (Ames) and mammalian cell assays and in in vivo clastogenicity assays (micronucleus) in mouse and rat.”
✓ VerifiedFDA pharmacology/toxicology review, p. 15Source ↗
Carcinogenicity
Mouse: malignant lymphoma (females) and hemangiosarcoma (both sexes) at all doses; rat: thyroid follicular tumors in high-dose males
“The carcinogenicity study in mouse was adequate and positive for malignant lymphoma in F at all doses and for hemangiosarcoma and combined hemangioma and hemangiosarcoma in M and F at all doses. The carcinogenicity study in rat was adequate and positive for thyroid follicular cell adenoma and combined follicular cell adenoma and carcinoma in HDM.”
✓ VerifiedFDA pharmacology/toxicology review, p. 15Source ↗
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
Teratogenic in rats; embryofetal lethality in rats and rabbits; no fetal NOAEL in rats, 0.1 mg/kg/day in rabbits
“In the reproductive and development studies, oral siponimod was teratogenic in rats and lethal to fetuses in both rats and rabbits, without a clear NOAEL for fetal toxicity in rats (<1 mg/kg/day) and a NOAEL of 0.1 mg/kg/day in rabbit.”
✓ VerifiedFDA pharmacology/toxicology review, p. 15Source ↗
Safety pharmacology
Decreased heart rate and second-degree AV block in guinea pigs and monkeys; decreased blood pressure in guinea pigs
“In cardiovascular safety pharmacology studies, oral siponimod acutely decreased heart rate and caused second-degree AV block in guinea pigs and monkeys, and decreased blood pressure in guinea pigs, with NOAELs of <0.03 mg/kg in guinea pigs and 60 mg/kg in monkeys.”
✓ VerifiedFDA pharmacology/toxicology review, p. 14Source ↗
Genotox: Ames
Negative
“Siponimod was negative in a battery of in vitro (Ames, chromosomal aberration in mammalian cells) and in vivo (micronucleus in mouse and rat) assays.”
Chromosomal aberration in mammalian cells: negative
“Siponimod was negative in a battery of in vitro (Ames, chromosomal aberration in mammalian cells) and in vivo (micronucleus in mouse and rat) assays.”
“Siponimod was negative in a battery of in vitro (Ames, chromosomal aberration in mammalian cells) and in vivo (micronucleus in mouse and rat) assays.”
Oral mouse and rat studies, up to 104 weeks; mouse: malignant lymphoma and hemangiosarcoma at all doses
“Oral carcinogenicity studies of siponimod were conducted in mice and rats. In mice administered siponimod (0, 2, 8, or 25 mg/kg/day) for up to 104 weeks, there was an increase in malignant lymphoma in females at all doses and in hemangiosarcoma and combined hemangioma and hemangiosarcoma at all doses in males and females.”
Not genotoxic overall: Ames negative; in vitro chromosome aberration positive without (not with) metabolic activation; rat micronucleus and comet negative