Acquired haemophilia A (AHA) is a rare but potentially life-threatening autoimmune disorder characterized by the development of autoantibodies against coagulation factor VIII (FVIII). While immunosuppressive therapy (IST) remains the cornerstone for eliminating inhibitors, clinicians often face challenges in managing acute bleeding. Recently, the use of Emicizumab in Acquired Haemophilia has gained traction as a prophylactic strategy to reduce bleeding risks during the vulnerable period before IST achieves complete remission.

Safety Profile of Emicizumab in Acquired Haemophilia

A recent interim analysis of a large-scale Japanese post-marketing surveillance study provided critical real-world insights into this therapeutic approach. Consequently, researchers evaluated 51 patients with AHA who received emicizumab alongside IST. Notably, the median age of the cohort was 76 years, reflecting the typical demographic of this condition. Furthermore, the analysis revealed that emicizumab is generally well tolerated. Although 49% of patients experienced adverse events, most were serious due to underlying comorbidities or infection, rather than the drug itself. Therefore, the benefit-risk profile remains favourable for this patient population.

Moreover, the study highlighted significant hemostatic efficacy. Patients who completed treatment achieved a median FVIII activity of approximately 60%. This increase continued even after the cessation of emicizumab. Additionally, only a small fraction of patients required bypassing agents like recombinant FVIIa after the initial loading dose period. This suggests that emicizumab effectively stabilizes hemostasis, thereby reducing the reliance on rescue hemostatic agents. However, clinicians must remain vigilant for infections, which accounted for several deaths unrelated to the study drug.

Clinical Implications for Practice

The integration of Emicizumab in Acquired Haemophilia management represents a significant advancement in personalizing care. It provides a reliable hemostatic bridge while IST works to eradicate the autoantibody. Consequently, this may lead to shorter hospitalizations and improved quality of life for elderly patients. Nevertheless, specialists should continue to follow established protocols for monitoring FVIII activity and adjusting IST doses. Overall, this real-world data reinforces the role of emicizumab as a safe and effective adjunctive therapy in AHA.

Frequently Asked Questions

What is the primary benefit of using emicizumab in acquired haemophilia?

Emicizumab provides effective bleeding prophylaxis by mimicking the function of factor VIII. This is particularly useful in AHA patients while they wait for immunosuppressive therapy to eliminate the autoantibodies, thus reducing the risk of life-threatening hemorrhages.

Are there significant thrombotic risks associated with emicizumab in AHA?

In this large-scale study, only one thromboembolic event occurred, which was determined to be unrelated to emicizumab. While caution is always advised when combining hemostatic agents, the real-world safety data suggests the risk is manageable when guidelines are followed.

Can emicizumab replace immunosuppressive therapy in AHA?

No, emicizumab is not a substitute for IST. While emicizumab manages the bleeding risk, IST is necessary to eliminate the factor VIII inhibitors and achieve a cure for the underlying autoimmune condition.

Disclaimer: This content is for informational and educational purposes only and does not constitute medical advice or a professional relationship between the reader and the author or publisher. Always seek the advice of your physician or another qualified healthcare provider with any questions you may have regarding a medical condition. Refer to the latest local and national guidelines for clinical practice.

References

Shima M et al. Real-World Use of Emicizumab in Patients With Acquired Haemophilia A: An Interim Safety Analysis of a Large-Scale Post‑Marketing Surveillance Study. Haemophilia. 2026 Apr 30. doi: 10.1111/hae.70301. PMID: 42059144.

Tiede A, et al. Management of acquired haemophilia A: 2020 updated international recommendations. Haemophilia. 2020;26(6):981-997. doi: 10.1111/hae.14125.

Oldenburg J, et al. Emicizumab Prophylaxis in Hemophilia A with Inhibitors. N Engl J Med. 2017;377(22):2184-2195. doi: 10.1056/NEJMoa1703068.