PB0167 - Emicizumab use in Acquired von Willebrand Disease: Single Case Report

Sunday, July 10, 2022

6:30 PM – 7:30 PM

Location: Exhibition

Presentation Format: In-Person

Presenting Author(s)

Miguel Escobar, MD

Professor of Medicine, Medical Director
University of Texas Health Science Center of Houston, McGovern Medical School, Gulf States Hemophilia and Thrombophilia Center, Houston, Texas
Houston, Texas, United States

Co-Author(s)

IA

Ibrahim Aboshady

Senior Research Scientist
The University of Texas Health Science Center at Houston, McGovern Medical School, Gulf States Hemophilia and Thrombophilia Center
Houston, Texas, United States
NM

Natalie A. Montanez

Nurse Practitioner, Certified Anticoagulation Care Provider
University of Texas Health Science Center of Houston, McGovern Medical School, Gulf States Hemophilia and Thrombophilia Center, Houston, Texas
Houston, Texas, United States

Background: Acquired von Willebrand syndrome (AVWS) is a rare bleeding disorder characterized by functional or structural defect of von Willebrand factor (VWF) often secondary to autoimmune or lymphoproliferative disorders. Management concentrates on eradicating autoantibody and achieving hemostasis. Currently, there are no evidence-based guidelines for management, however potential of emicizumab prophylaxis in the management of severe congenital von Willebrand disease has been reported.

Aims: Describe the use of emicizumab prophylaxis in the management of AVWS.

Methods: Chart review of 70 y/o Caucasian female diagnosed with AVWS in the setting of Rheumatoid Arthritis (RA) and Parkinson's disease following recurrent GI bleeding unresponsive to VWF replacement. Coagulation studies suggest severe von Willebrand disease (FVIII 5%, VWF: Ag 11%, VWF R:Co < 15%), full gene sequencing of the VWF (exons 1-52) resulted in negative findings, with normal VWF GP1bM and VWF propeptide antigen assay. Suggesting markedly low VWF antigen is due to increased clearance of VWF without inhibition of function secondary to acquired inhibitor, likely resulting from active RA.

Results: Emicizumab standard prophylaxis (1.5 mg/kg/ once weekly) started following waning response to maintenance IVIG ~1000 mg/kg/dose every 4 weeks. Despite coagulation studies remaining at baseline (C: FVII 10%, VWF: Ag 12%, VWF R: Co < 15%) patient experienced no reported bleed events within the first 6 months, with increased Hemoglobin. Emicizumab equivalent FVIII levels averaged 28.6 µg/ml. Eradication of autoantibody remains unachievable lack of response to management of underlying disease mechanisms (RA) with Rituximab and Methotrexate.

Conclusion(s): In patients with AVWS, use of low dose IVIG maintenance therapy can achieve temporary favorable response to prevent bleeding symptoms with declining response noted ≥6 months. While the use of emicizumab prophylaxis in AVWS is very limited this case illustrates its efficacy and safety using standard dose prophylaxis in an AVWS patient with multiple comorbidities. Further studies in this disease are warranted.