In Period 2, the subjects receive multiple doses of FG 4592. On Day 7 of Period 2, FG 4592 is given concomitantly with warfarin. After completion of all assessments on Day 16 of Period 2, subjects are discharged from the clinic on the condition that there are no medical reasons for a prolonged stay. The subjects return for an End of Study Visit (ESV) 5 to 9 days after the last assessment of Period 2 (or after early withdrawal).