Moreover, ASP5878 did not affect the hERG current up to 10 µM by in vitro patch-clamp assay, and a single oral dose of ASP5878 at 1, 10, and 100 mg/kg did not induce serious adverse effects on the central nervous, cardiovascular, and respiratory systems in dogs. Furthermore, ASP5878 exhibited lower total clearance than hepatic blood flow and high oral bioavailability in rats and dogs, and moderate brain penetration in rats.