Negative in Ames, mouse lymphoma forward mutation and in vivo mouse micronucleus assays
“Arimoclomol was not genotoxic in the Ames assay at up to 5,000 µg/plate, was not mutagenic in the mouse forward mutation assay at up to 1,000 µg/ml, or in the in vivo mouse micronucleus assay at doses up to 2,500 mg/kg/day.”
2-year rat and 26-week rasH2 mouse: no increase in tumors
“In a 2-year carcinogenicity study in Han Wistar rats, and a 26-week carcinogenicity study in Transgenic rasH2 mice, oral administration of arimoclomol did not increase the incidence of tumors at systemic exposures that were approximately 8-fold and 11-fold the human exposure, based on AUC at the MRHD.”
Rat FEED: reduced fertility, fewer corpora lutea and pre-implantation loss at 1,000 mg/kg/day; fertility NOAEL 750 mg/kg/day
“In fertility and early embryonic development study (FEED) in rats, an arimoclomol dose of 1,000 mg/kg/day reduced fertility and the fecundity index in male and female rats, resulted in reduction in the number of corpora lutea, and increased pre-implantation loss in female rats. The NOAEL for the fertility study in rats is considered to be 750 mg/kg/day, which is equivalent to a 4-fold safety margin for the 600 mg/day clinical dose.”
10% QTc increase in 2-week dog studies at ~28-fold human exposure
“Additional findings in the canine 2-week repeat dose toxicity studies noted a 10% increase in the QTc interval at the end of the dosing at exposures corresponding to about 28-fold the human exposure.”
Not genotoxic overall: Ames negative; in vitro chromosome aberration positive without (not with) metabolic activation; rat micronucleus and comet negative