Improved Joint Status and Reduced Joint Bleeding Through Double-Dose Emicizumab in a Patient with Severe Hemophilia A Without Inhibitor

Introduction Despite major advances in prophylaxis for severe hemophilia A, some patients without inhibitors continue to experience breakthrough bleeds, progressive arthropathy, or reduced quality of life [ 1 ]. Emicizumab, a bispecific antibody mimicking activated factor VIII, offers effective subcutaneous prophylaxis; however, in certain clinical situations, standard dosing may not provide sufficient protection [ 2 ] [ 3 ]. This case report describes a long-term outcome in a patient with severe hemophilia A who achieved sustained bleeding control and improvement of joint function following escalation to a double-dose Emicizumab regimen after insufficient clinical response to standard dosing. Method A 59-year-old male (75 kg, 184 cm) with severe hemophilia A (FVIII activity200,000 IU in 2020). After approval for double-dose prophylaxis in October 2020, the patient was entirely bleed-free for three years (October 2020–October 2023), with improved joint mobility, reduced pain, and no need for factor replacement except perioperatively for knee arthroplasty in 2021. HIV infection remained well controlled, and hepatitis C was successfully treated. Fig. 1 Treatment Timeline of Factor VIII Consumption, Emicizumab Levels, and Bleeding Outcomes . The figure illustrates the patient’s treatment course over the period of 2018–2023. The upper panel shows annual F-VIII consumption (yellow bars) and Emicizumab levels (right-aligned blue graph). The lower panel details therapeutic interventions, phases of intensified Emicizumab dosing, adjunct procedures such as Radiosynoviorthesis (RSO), Total Knee Endoprosthesis (TEP), and the corresponding annual joint bleeding rates (AjBR). The timeline demonstrates a marked reduction in F-VIII requirement and improved hemostatic control following reinstatement of the intensified Emicizumab regimen. Conclusion This case demonstrates that individualized dose escalation of Emicizumab can lead to long-term bleeding prevention and improved joint health in patients with severe hemophilia A without inhibitors who show insufficient clinical response to standard dosing. Personalized Emicizumab regimens may represent a valuable option in complex cases, particularly in those with advanced arthropathy or comorbidities affecting venous access. Publication History Article published online: 17 February 2026 © 2026. Thieme. All rights reserved. Georg Thieme Verlag KG Oswald-Hesse-Straße 50, 70469 Stuttgart, Germany