This study will assess whether exposure response analysis of the electrocardiographic QTc and
J-Tpeakc intervals in Phase 1 clinical pharmacology studies can be used to confirm that drugs
that predominantly block the potassium channel encoded by the human ether-à-go-go-related
gene (hERG) with approximately equipotent late sodium and/or calcium block ("balanced ion
channel" drugs) do not cause J-Tpeakc prolongation and that drugs that predominantly block
hERG without late sodium or L-type calcium current block ("predominant hERG" drugs) cause QTc
prolongation.