A Study of Bometase Alfa for Bleeding Control in Acquired Hemophilia A

• Age ≥18 years;

• Confirmed diagnosis of acquired hemophilia A, meeting the following criteria:

  1. Isolated prolongation of activated partial thromboplastin time (APTT) with a normal prothrombin time (PT);
  2. Reduced factor VIII coagulant activity (FVIII:C \<50%);
  3. Positive FVIII inhibitor, defined as ≥0.6 BU/mL as measured by the Bethesda assay or Nijmegen-modified Bethesda assay, or failure of a 1:1 mixing study with normal plasma to achieve complete correction;
  4. No evidence of congenital hemophilia, von Willebrand disease, or lupus anticoagulant;
• Presence of clinically significant active bleeding, including, but not limited to, muscle or subcutaneous hematoma, gastrointestinal or genitourinary bleeding, postpartum or postoperative bleeding, or deep-seated or life-threatening organ bleeding;
• Provision of written informed consent by the patient and/or a legally authorized representative;
• Ability to comply with the study follow-up schedule for at least 30 da

Exclusion Criteria:

• Congenital hemophilia A or B, or any other confirmed congenital coagulation factor deficiency;
• Isolated prolonged activated partial thromboplastin time (APTT) due to lupus anticoagulant or antiphospholipid syndrome, with a negative FVIII inhibitor and normal FVIII activity; or coagulation abnormalities caused by disseminated intravascular coagulation (DIC) or severe liver disease that do not fulfill the diagnostic criteria for acquired hemophilia A;
• A history or symptoms of any arterial or venous thromboembolic event within 3 months before enrollment, including atherosclerosis, myocardial infarction, ischemic stroke, transient ischemic attack, deep vein thrombosis, or pulmonary embolism, or the presence of DIC;
• Use of factor VII (FVII), activated factor VII (FVIIa), tranexamic acid, or aminocaproic acid within 1 day before the planned administration of the study drug; or use of prothrombin complex concentrate (PCC) or factor VIII (FVIII) within 3 days before the first administration;
• Female participants who are pregnant or breastfeeding, or have a positive pregnancy test;
• Known hypersensitivity to the investigational product or any of its excipients;
• Inability to obtain informed consent, including patients unable to express their wishes and without a legally authorized representative;
• Inability to comply with the study follow-up requirements or investigator-determined poor compliance;
• Any other condition for which the investigator considers the participant unsuitable for study participation.