No margin: no adverse effects at clinical free AUC exposure; no adverse findings in dogs only at exposures below clinical total AUC
“No adverse effects for either species were observed with chronic dosing at clinical exposure based on free AUC and up to 3-fold based on free Cmax. No adverse findings occurred in dogs at exposures less than clinical total AUC and total Cmax.”
Heart primary target in rats and dogs; dose- and duration-dependent cardiac toxicity up to heart failure from exaggerated pharmacology
“The heart was identified as the primary organ of toxicity in both species with repeated aficamten administrations. Cardiac toxicities culminating in heart failure resulting from exaggerated pharmacology of the drug were observed in both rats and dogs in a dose- and duration-dependent fashion.”