Emicizumab Use in Treatment of Acquired Hemophilia A: A Case Report

BACKGROUND Acquired hemophilia A (AHA) is a rare hemorrhagic disorder that is caused by producing autoantibodies against factor VIII. It is usually characterized by severe, spontaneous bleeding, which can be life-threatening. The current standard treatments for bleeding prophylaxis are highly effective but accompanied with some disadvantages such as frequent intravenous infusions, high cost, and risk of thromboembolic complications. Emicizumab is a bispecific antibody with a therapeutic FVIII-mimetic nature. Emicizumab has shown a reduction in annualized bleeding rate in congenital hemophilia patients with and without inhibitors. The pathophysiological concepts and preclinical data suggest that Emicizumab can be effectively used for treating AHA. CASE REPORT We present the case of an 87-year-old woman admitted for symptomatic anemia and large chest wall and pelvic hematomas confirmed by imaging, without history of trauma. Her coagulation studies showed isolated prolonged activated partial thromboplastin time (aPTT), low factor VIII activity level, and high levels of factor VIII inhibitor. She was successfully treated with activated prothrombin complex concentrate (aPCC), which was transitioned to Emicizumab on discharge. No recurrent bleeding episodes or adverse events related to Emicizumab were reported during the 2-month follow-up period. CONCLUSIONS A subcutaneous weekly or biweekly injection of Emicizumab, a recombinant monoclonal antibody, offers several advantages: less frequent infusions, good hemostatic efficacy, possible outpatient therapy, and even more cost-effective than bypassing agents. More clinical studies should be conducted to compare Emicizumab with the current standards of care.