Thromb Haemost 2020; 120(10): 1357-1370
DOI: 10.1055/s-0040-1714279
Review Article

Bridging the Missing Link with Emicizumab: A Bispecific Antibody for Treatment of Hemophilia A

Georg Gelbenegger
1  Department of Clinical Pharmacology, Medical University of Vienna, Vienna, Austria
,
Christian Schoergenhofer
1  Department of Clinical Pharmacology, Medical University of Vienna, Vienna, Austria
,
Paul Knoebl
2  Division of Hematology, Department of Internal Medicine I, Medical University of Vienna, Vienna, Austria
,
Bernd Jilma
1  Department of Clinical Pharmacology, Medical University of Vienna, Vienna, Austria
› Author Affiliations
Funding G.G. is supported by grant SFB54-P04 from the Austrian Science Funds.

Abstract

Hemophilia A, characterized by absent or ineffective coagulation factor VIII (FVIII), is a serious bleeding disorder that entails severe and potentially life-threatening bleeding events. Current standard therapy still involves replacement of FVIII, but is often complicated by the occurrence of neutralizing alloantibodies (inhibitors). Management of patients with inhibitors is challenging and necessitates immune tolerance induction for inhibitor eradication and the use of bypassing agents (activated prothrombin complex concentrates or recombinant activated factor VII), which are expensive and not always effective. Emicizumab is the first humanized bispecific monoclonal therapeutic antibody designed to replace the hemostatic function of activated FVIII by bridging activated factor IX and factor X (FX) to activate FX and allow the coagulation cascade to continue. In the majority of hemophilic patients with and without inhibitors, emicizumab reduced the annualized bleeding rate to almost zero in several clinical trials and demonstrated a good safety profile. However, the concurrent use of emicizumab and activated prothrombin complex concentrate imposes a high risk of thrombotic microangiopathy and thromboembolic events on patients and should be avoided. Yet, the management of breakthrough bleeds and surgery remains challenging with only limited evidence-based recommendations being available. This review summarizes published clinical trials and preliminary reports of emicizumab and discusses the clinical implications of emicizumab in treatment of hemophilia A.



Publication History

Received: 23 February 2020

Accepted: 08 June 2020

Publication Date:
27 July 2020 (online)

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