KR-33493 is a potent inhibitor of Fas-mediated cell death (FAF1). IC50 & Target: FAF1^[1] In Vivo: Body weight changes of both sexes are not related to KR-33493 in all doses. In rats administrated KR-33493 for 4 weeks, no test article-related changes in any treated groups of either sex are found in hematology, serum biochemistry, and urinalysis. In dogs administrated KR-33493 for 2 weeks, red blood cell count (RBC) value in males is significantly higher at the 1000 mg/kg/day dose than that of the control group (i.e., 6.96±0.323 vs. 6.12±0.418). However, the change of RBC is recovered after the end of the administration period. The dose-normalized AUC_last is not significantly different between the groups, suggesting that KR-33493 is governed by linear kinetics^[1].