The primary endpoint is annualized number of bleeding episodes, compared between the first on-demand period and each of the prophylaxis regimens. A comparison of annualized bleeding episodes between the two prophylaxis regimens will also be performed. Subject-reported outcomes will also be collected using a patient diary. At 24 and 48 hours following the onset of each joint bleeding episode, information on pain, sleep, and work will be collected. Additional data on physical functioning will be recorded on the diary at the end of the 16-week on-demand period, and at the end of each prophylaxis period. Information on safety will also be collected.