The initial serious ("qualifying") bleeding episode for each subject was analyzed for the primary efficacy outcome measure. A 'positive response' is defined as 'effective' (bleeding stopped with clinical control and FVIII levels of 50% or higher ) or 'partially effective' (bleeding reduced with clinical stabilization and FVIII levels of 20% or higher) control of bleeding, as determined by the investigator using a 4-point rating scale (effective - partially effective - poorly effective - not effective). 'Poorly effective' is defined as 'bleeding slightly reduced or unchanged and FVIII levels of less than 50%'. 'Not effective' is defined as 'bleeding worsening and FVIII levels of less than 50%'.

Intent to Treat (ITT) population = 29 subjects with initial serious bleeding episodes

Treatment success was defined as control of qualifying bleeding episode at the time of final treatment dosing. A serious bleeding episode was considered 'successfully controlled' if the investigator had checked 'completed OBI-1 therapy as treatment success' on the eCRF.

ITT population = 29 subjects with initial serious bleeding episodes (BEs)

A 'positive response' is defined as 'effective' (bleeding stopped with clinical control and FVIII levels of 50% or higher ) or 'partially effective' (bleeding reduced with clinical stabilization and FVIII levels of 20% or higher) control of bleeding, as determined by the investigator using a 4-point rating scale (effective - partially effective - poorly effective - not effective). 'Poorly effective' is defined as 'bleeding slightly reduced or unchanged and FVIII levels of less than 50%'. 'Not effective' is defined as 'bleeding worsening and FVIII levels of less than 50%'.

21 subjects of the ITT population (n=29) had responses available at 8 hours after initial infusion of OBI-1.

A 'positive response' is defined as 'effective' (bleeding stopped with clinical control and FVIII levels of 50% or higher ) or 'partially effective' (bleeding reduced with clinical stabilization and FVIII levels of 20% or higher) control of bleeding, as determined by the investigator using a 4-point rating scale (effective - partially effective - poorly effective - not effective). 'Poorly effective' is defined as 'bleeding slightly reduced or unchanged and FVIII levels of less than 50%'. 'Not effective' is defined as 'bleeding worsening and FVIII levels of less than 50%'.

19 subjects of the ITT population (n=29) had responses available at 16 hours after initial infusion of OBI-1.

'Frequency of infusions' was calculated as the 'average number of infusions per day'. 'Qualifying bleeding episode' was defined as the 'initial, serious bleeding episode'.

The analysis was performed in 25 of 29 participants in the ITT population whose 'qualifying' bleeding episode was controlled successfully.

'Qualifying bleeding episode' was defined as the 'initial, serious bleeding episode'.

The analysis was performed in 25 of 29 participants in the ITT population whose 'qualifying' bleeding episode was controlled successfully.

'Qualifying bleeding episode' was defined as the 'initial, serious bleeding episode'. A serious bleeding episode was considered 'successfully controlled' if the investigator had checked 'completed OBI-1 therapy as treatment success' on the eCRF.

The analysis was performed in 25 of 29 participants in the ITT population whose 'qualifying' bleeding episode was controlled successfully.

Of 21 subjects in the ITT population (n=29) with responses available at 8 hours after initial infusion of OBI-1, 20 had a positive response.

All 19 subjects in the ITT population (n=29) who had responses available at 16 hours after initial infusion of OBI-1 had a positive response.

29 subjects (ITT population) had responses available at 24 hours after initial infusion of OBI-1.

Because of expected sparseness of positive anti-OBI-1 antibody titers, formal statistical analyses of correlation were not performed.

Participation in the PK sampling was optional. PK parameters obtained from the non-bleeding state were summarized with descriptive statistics.

PK population (= all subjects in the ITT population who consent to PK draws and have factor VIII levels measured at the central reference laboratory)

Participation in the PK sampling was optional. PK parameters obtained from the non-bleeding state were summarized with descriptive statistics.

PK population

Participation in the PK sampling was optional. PK parameters obtained from the non-bleeding state were summarized with descriptive statistics. AUC was calculated as area under the percent activity-time curve.

PK population

Participation in the PK sampling was optional. PK parameters obtained from the non-bleeding state were summarized with descriptive statistics. Half-life was calculated as the time it took to reduce percent activity by half.

PK population

28 eligible subjects with acquired hemophilia A in the ITT population (n=29), of whom 18 had no detectable anti-porcine FVIII inhibitor titers at baseline (<0.6 BU) and 10 had detectable anti-porcine FVIII antibody titers at baseline (>=0.6 BU)

21 subjects in the ITT population (n=29) with available baseline and follow-up test results

Anti-human factor VIII antibody titer data were presented in subject data listings. No statistical test was planned for anti-human factor VIII antibody titer.