Number of participants with clinically significant FVIII inhibitor development after switching from ReFacto to moroctocog alfa (AF-CC). Clinically significant inhibitors are defined as a central laboratory confirmed positive inhibitor (≥ 0.6 Bethesda unit (BU) using the Nijmegen modification of the Bethesda assay present at 2 consecutive blood draws within a 6-week interval) and within 28 days before the initial or within 28 days following the second positive FVIII inhibitor sample collection one of the following: the need for the participant to administer alternative hemostatic products in order to achieve sufficient efficacy, or ≥2 adverse event reports of decreased drug effect (or other adverse event indicating a decrease in the efficacy of the test article). The blood sample collection for these results must also be between the date of first dose of study medication and 28 days after the last dose of study medication.

All enrolled participants who took at least 1 dose of ReFacto AF study drug were included in the safety and efficacy analyses.

An ABR for each participant will be calculated as the number of bleeds requiring administration of FVIII replacement product (taken from the Infusion Log Diary case report form), divided by his total therapy duration (in days), then multiplied by 365.25.

All enrolled participants who took at least 1 dose of ReFacto AF study drug were included in the safety and efficacy analyses.

A 4-point scale of assessment of 'on-demand' treatment (administration of an unscheduled bolus infusion of Refacto-AF to stop bleeding) is defined as:

• Excellent: Definite pain relief and/or improvement in signs of bleeding starting within 8 hours after an infusion, with no additional infusion administered.
• Good: Definite pain relief and/or improvement in signs of bleeding starting within 8 hours after an infusion, with at least one additional infusion administered for complete resolution of the bleeding episode; or, Definite pain relief and/or improvement in signs of bleeding starting after 8 hours following the infusion, with no additional infusion administered.
• Moderate: Probable or slight improvement starting after 8 hours following the infusion, with at least one additional infusion administered for complete resolution of the bleeding episode.
• No Response: No improvement at all between infusions or during the 24-hour interval following an infusion, or condition worsens.

All enrolled participants who took at least 1 dose of ReFacto AF study drug were included in the safety and efficacy analyses.

The Infusion Log Diary case report form (CRF) was used to determine the number of test article infusions administered to treat a bleed. This was calculated by adding the initial (on-demand) infusion to any subsequent (on-demand) infusions for the same bleed (same bleed start date/time).

All enrolled participants who took at least 1 dose of ReFacto AF study drug were included in the safety and efficacy analyses.

First, the bleed start time from the Infusion Log Diary CRF was used to determine the number of breakthrough bleeds that occurred ≤48 hours after an infusion marked as "Prophylaxis" (which had no associated bleed). If there was more than 1 bleed location (ie, ankle and joint) with identical bleed start date and time, it was treated as 1 bleed occurrence. If a response was given, or if a bleed time was given, but "On Demand" was not listed as "treatment type", it was still counted as an on-demand bleed for analyses/summaries. Bleeding episodes were not categorized as spontaneous (atraumatic) or traumatic.

All enrolled participants who took at least 1 dose of ReFacto AF study drug were included in the safety and efficacy analyses.

The number of participants with any breakthrough bleed was reported.

All enrolled participants who took at least 1 dose of ReFacto AF study drug were included in the safety and efficacy analyses.

The total amount (in International Units [IU]) infused for each test article infusion recorded in the Infusion Log Diary CRF was summed to calculate the TFC for each participant.

All enrolled participants who took at least 1 dose of ReFacto AF study drug were included in the safety and efficacy analyses.

The total amount (in IU) infused for each test article infusion recorded in the Infusion Log Diary CRF was summed to calculate the TFC for each participant.

All enrolled participants who took at least 1 dose of ReFacto AF study drug were included in the safety and efficacy analyses.

The average infusion dose for each participant was calculated as his total factor consumption (in IU) divided by the number of infusions administered. Summary statistics were reported for both of these variables separately for those participants classified at baseline as following an on-demand regimen, and for those on a primary or secondary prophylaxis regimen.

All enrolled participants who took at least 1 dose of ReFacto AF study drug were included in the safety and efficacy analyses.

The calculation of incidence of on-demand LETE used the number of bleeds identified as, or with a result of, LETE as the numerator (from the On Demand LETE CRF), and the denominator was the number of bleeding episodes treated in an on-demand setting. This denominator could include new bleeding episodes in prophylaxis participants breakthrough bleeds), and if subsequent on-demand doses for such a bleed met the on-demand LETE criteria, then an on-demand LETE was reported.

All enrolled participants who took at least 1 dose of ReFacto AF study drug were included in the safety and efficacy analyses.

The calculation of incidence of prophylaxis LETE used the number of bleeds identified as, or with a result of, LETE as the numerator (from the Prophylactic LETE CRF), and the denominator was the number of routine prophylaxis infusions. Each infusion was classified in the infusion log ("Prophylaxis/ On Demand/ Preventive"), and participants were instructed to select "On Demand" if the infusion was to treat a bleed, even if the participant typically followed a prophylaxis regimen. Only the infusions classified as "Prophylaxis" were counted in this denominator.