Study of TAK-672 in Participants With Acquired Hemophilia A

Inclusion criteria

• Male or female Japanese participants of >=18 years of age.
• Participants who (or their legally authorized representatives) have provided his/her written informed consent form prior to any study-related procedures and study product administration.
• Participants with a diagnosis of AHA based on clinical evaluation and supportive local laboratory testing as shown below:

• Presentation with spontaneous bleeding without anatomical cause and without prior known bleeding disorder.
• Prolonged activated partial thromboplastin time (aPTT) without explanation.
• Abnormal aPTT cross mixing test consistent with FVIII inhibitors
• Confirmation of a low FVIII:C.
• Positive FVIII inhibitor (>=0.6 BU) as measured either in the local or central laboratory
• Participants with a severe bleeding episode which the investigator finds necessary to treat and whose severe bleeding episode meets at least 1 of the following criteria:

• Bleeds that pose a threat to a vital organ that could threaten life (e.g. intracranial bleed, or any site that could obstruct the airway).
• Bleeds that pose a threat to a vital organ where life is not threatened but the organ function could be impaired (e.g., intraspinal bleed threatening the spinal cord and/or nerve conduction; a continual bleed into the kidney or bladder that could result in an obstructive uropathy, testicular bleed, bleed in and around the eye).
• Bleeds requiring a blood transfusion to maintain the Hgb level at above-life or organ threatening levels (e.g. post-surgical, gastro-intestinal, retro-peritoneal, and thigh bleeds).
• Intramuscular bleeds where muscle viability and/or neurovascular integrity is significantly compromised or at risk of being compromised.
• Intra-articular bleeds impacting a major joint associated with severe pain, swelling and severe loss of joint mobility (reduced >70%) or where a bleed could result in joint destruction (e.g. in and around the femoral head).
• Participants who are taking anti-thrombotics (including anti-platelet agents and anticoagulantswith confirmatory laboratory testing documenting specific FVIII inhibitor titer and with 3 half-lives of the agent have elapsed since the last dose.
• Participants with expected life expectancies of at least 90 days prior to the onset of the hemorrhagic episode.
• Participants of reproductive age who have agreed to use acceptable methods of contraception and if female, undergo pregnancy testing as part of the screening process.
• Participant who are able to willing and able to comply with the requirements of the protocol.

Exclusion criteria

• Participants with an established reason for bleeding that is not correctable even with hemostatic therapy.
• Participants presenting a bleeding episode that is assessed likely to resolve on its own, even if left untreated.
• Participants with a known major sensitivity (anaphylactoid reactions) to therapeutic products of porcine or hamster origin; examples include therapeutics of porcine origin (e.g. previously marketed porcine FVIII, Hyate: C) and recombinant therapeutics prepared from hamster cells (e.g. Humira, Advate, and Enbrel).
• Participants with the use of hemophilia medication: prior to the administration of TAK-672 under one of the following conditions: (1) use of "recombinant activated factor VII (rFVI)Ia " within 3 hours prior to TAK-672 administration (2) use of " activated prothrombin complex concentrate (aPCC)" within 6 hours prior to TAK-672 administration or (3) use of " plasma-derived FX/FVIIa complex concentrate (pd-FX/FVIIa) " within 8 hours prior to TAK-672 administration.
• Participants with an anticipated need for treatment or device during the study that may interfere with the evaluation of the safety or efficacy of TAK-672, or whose safety or efficacy may be affected by TAK-672.
• Participants who are currently pregnant or breastfeeding, or planning to become pregnant or father a child during the study
• Participants who have participated in another clinical study and has been exposed to an investigational product or device within 30 days prior to the study enrollment.
• Participants who are scheduled to participate in another non-observational (interventional) clinical study involving an investigational product or device during the course of the study.
• Participants who are unable to or unwilling to comply with the study design, protocol requirements, and/or the follow-up procedures.
• Participants whose majority of age are under legal protection.
• Participants who are an immediate family member, study site employee, or are in a dependent relationship with a study site employee who is involved in the conduct of this study (e.g. spouse, parent, child, sibling) or may consent under duress.
• Participants who are judged by the investigator as being ineligible for any other reason.