“The rat and monkey were determined to be the most appropriate toxicological species, given the emetic effect observed in dogs.”
✓ VerifiedFDA multi-discipline review, p. 39Source ↗
Why that species
Rat: higher exposure and sensitivity; monkey: metabolic profile closest to human; dog excluded due to emesis
“agrees based on the higher systemic exposure (and consequently, higher sensitivity) observed in the rat and the more similar metabolic profile of the monkey compared to humans. The reviewer agrees the emetic effect in the dog would lead to drug exposure inconsistencies and problems with data interpretation.”
✓ VerifiedFDA multi-discipline review, p. 532Source ↗
Surrogate molecule
Yes: most of the toxicology program used mix-ISA247 (isomer mixture), bridged to voclosporin
“As most studies were performed using mix-ISA247, a bridging programme was performed with voclosporin which included a 13-week study in the rat.”