To provide emergency access to OBI-1 for patients with Acquired Hemophilia and a serious bleeding episode who do not have access to an active clinical study site associated with the OBI-1-301 study.

Inclusion Criteria:

• Written informed consent from participant or their legal representative.
• Participants with acquired hemophilia with autoimmune inhibitors to human factor VIII.
• Has a serious bleeding episode, as documented by the investigator.
• Be willing and able to follow all instructions and attend all study visits.
• Participants taking anti-thrombotics may be included depending on the time elapsed since taking such medications.
• Life expectancy of at least 90 days prior to the onset of the bleeding episode.

Exclusion Criteria:

• Hemodynamically unstable after blood transfusion, fluid resuscitation and pharmacologic or volume replacement pressor therapy.
• Has an established reason for bleeding that is not correctable.
• Bleeding episode assessed likely to resolve on its own if left untreated.
• Anti-OBI-1 inhibitor that exceeds 20 BU (prospectively or retrospectively).
• Subsequent bleeding episode at the site of the initial qualifying bleeding episode within 2 weeks following the final OBI-1 dose for the initial qualifying bleeding episode, or subsequent bleeding episode at a different site than the initial qualifying bleeding episode within 1 week following the final OBI-1 dose for the initial qualifying bleeding episode will not be considered "new" qualifying bleeding episodes.
• Prior history of bleeding disorder other than acquired hemophilia.
• Known major sensitivity (anaphylactoid reactions) to pig or hamster products.
• Use of hemophilia medication within 3 to 6 (depending on medication) hours prior to OBI-1 administration.
• Participation in any other clinical study within 30 days of the first OBI 1 treatment.
• Anticipated need for treatment or device during the study that may interfere with the evaluation.
• Abnormal baseline findings
• Inability or unwillingness to comply with the study design, protocol requirements, or the follow-up procedures.