Recombinant vWF Concentrate and ECMO

February 2, 2026 updated by: Michael Mazzeffi, MD, University of Virginia

Safety and Tolerability of Recombinant Von Willebrand Factor Concentrate in Adult ECMO Patients With Major Bleeding: A Phase I Study

Adult patients on extracoporeal membrane oxygenation (ECMO) frequently experience bleeding, which is in part caused by acquired von Willebrand syndrome (vWS). Prior in vitro studies have shown that the addition of recombinant von Willebrand Factor (vWF) to ECMO patient blood samples, normalizes platelet adhesion and thrombus formation. This study is a phase I study, where adult ECMO patients with refractory bleeding will be treated with recombinant vWF a single time. The primary objectives are to evaluate the safety, tolerability, and pharmacokinetics of recombinant vWF in adult ECMO patients.

Study Overview

Status

Recruiting

Conditions

Detailed Description

Coagulopathic bleeding is a common complication during ECMO. Multiple studies suggest that major bleeding occurs in 30-70% of adult ECMO patients, with higher bleeding rates in post-cardiotomy shock and veno-arterial (VA) ECMO patients. The pathophysiology of ECMO-induced coagulopathy is complex with multiple factors contributing, including loss of large VWF multimers, thrombocytopenia, increased tissue factor pathway inhibitor levels, and platelet surface glycoprotein (GP)1ba shedding. Adult ECMO patients almost universally develop acquired von Willebrand syndrome due to loss of large VWF multimers. In a study by Kalbhenn et al., acquired von Willebrand syndrome occurred within the first 6 hours of ECMO initiation in all patients (N=59) and returned to normal within 24 hours of ECMO decannulation. The loss of large VWF multimers that occurs in ECMO patients leads to poor platelet adhesion at an injury site and excess bleeding, which in some cases can become life-threatening.

In a prior observational study, the investigators found that when adult ECMO patients with acquired von Willebrand syndrome were treated with plasma-derived vWF concentrate, it increased plasma ristocetin cofactor activity (RCo), increased the RCo-VWF antigen ratio, and improved clinical hemostasis. This preliminary data suggests that use of VWF may help to reduce bleeding in ECMO patients and is safe.

Recombinant VWF has superior ultra-large multimer content, and thus it may be even better suited to treat acquired von Willebrand syndrome, which is represented by severe loss of large vWF multimers, similar to Type 2a von Willebrand disease. Further, recombinant VWF has a longer plasma half-life than plasma-derived VWF and may be safer because it contains no Factor VIII. Factor VIII activity is often supranormal during ECMO and overaccumulation of Factor VIII can increase thrombotic risk, particularly when there is blood stasis. In two prior in vitro studies, the investigators found that when recombinant VWF was added to ECMO patient blood samples, primary hemostasis/platelet adhesion returned towards normal. In a study that compared the addition of recombinant VWF to plasma-derived VWF, the investigators found that recombinant VWF improved primary hemostasis more, while having minimal impact on thrombin generation. These data suggest that recombinant VWF may be more effective in restoring primary hemostasis, and also may have a superior safety profile. The current study will investigate the safety and tolerability of recombinant VWF in adult ECMO patients with major bleeding.

Study Type

Interventional

Enrollment (Estimated)

12

Phase

  • Phase 1

Contacts and Locations

This section provides the contact details for those conducting the study, and information on where this study is being conducted.

Study Contact

Study Contact Backup

Study Locations

    • Virginia
      • Charlottesville, Virginia, United States, 22903

Participation Criteria

Researchers look for people who fit a certain description, called eligibility criteria. Some examples of these criteria are a person's general health condition or prior treatments.

Eligibility Criteria

Ages Eligible for Study

  • Adult
  • Older Adult

Accepts Healthy Volunteers

No

Description

Inclusion Criteria:

  1. Adult patients (18 years or greater)
  2. On extracorporeal membrane oxygenation
  3. Major bleeding defined by CTCAE class 3 or greater
  4. Off systemic anticoagulation for at least 4 hours

Exclusion Criteria:

  1. Platelet count less than 40 x 109/L
  2. International normalized ratio> 2.0
  3. Fibrinogen less than 150 mg/dL
  4. Current participation in another clinical trial (interventional)
  5. Heparin induced thrombocytopenia (active)
  6. Acute liver failure, as indicated by bilirubin >20 mg/dL or new onset hepatic encephalopathy
  7. Patient or legally authorized representative unable to give informed consent
  8. Allergy to recombinant von Willebrand Factor or any component of the product based on prior exposure
  9. Of childbearing age and positive pregnancy test during the same hospital admission, a pregnancy test will be mandatory for all women of child-bearing age
  10. Known congenital or acquired thrombophilia
  11. History of deep venous thrombosis, pulmonary embolism, circuit thrombosis, disseminated intravascular coagulation (DIC), ischemic stroke, ST elevation myocardial infarction (STEMI), or arterial thrombosis in the last 3 months.
  12. History of hypersensitivity to vWF concentrate
  13. Known history of vWF antibodies

Study Plan

This section provides details of the study plan, including how the study is designed and what the study is measuring.

How is the study designed?

Design Details

  • Primary Purpose: Treatment
  • Allocation: N/A
  • Interventional Model: Single Group Assignment
  • Masking: None (Open Label)

Arms and Interventions

Participant Group / Arm
Intervention / Treatment
Experimental: Treatment with recombinant vWF
ECMO patients with major bleeding who are enrolled in the trial will receive treatment with recombinant von Willebrand Factor a single time. The dose will be 50 IU/kg and the drug will be given intravenously.
Recombinant von Willebrand Factor is a drug that is currently FDA approved to treat patients with certain types of von Willebrand Disease. In the current trial it will be used to treat ECMO patients who have acquired von Willebrand syndrome.

What is the study measuring?

Primary Outcome Measures

Outcome Measure
Measure Description
Time Frame
Serious Adverse Events
Time Frame: 30 days after treatment
Events that 1) cause death, 2) are life-threatening, 3) cause permanent damage, 4) required intervention to prevent harm, or 5) are otherwise serious and jeopardize the patient's safety.
30 days after treatment
Area under the plasma concentration curve from zero to infinity (h × U/dL)
Time Frame: 96 hours after treatment
Pharmacokinetic parameter
96 hours after treatment
Plasma half-life (hours)
Time Frame: 96 hours after treatment
Pharmacokinetic parameter
96 hours after treatment
Mean residence time (hours)
Time Frame: 96 hours after treatment
Pharmacokinetic parameter
96 hours after treatment
Clearance (mL/kg per hour)
Time Frame: 96 hours after treatment
Pharmacokinetic parameter
96 hours after treatment
Volume at a steady state (dL/kg)
Time Frame: 96 hours after treatment
Pharmacokinetic parameter
96 hours after treatment
Maximum concentration (U/dL)
Time Frame: 96 hours after treatment
Pharmacokinetic parameter
96 hours after treatment
Time to maximum concentration (hours)
Time Frame: 96 hours after treatment
Pharmacokinetic parameter
96 hours after treatment
Incremental recovery ([U/dL]/[U VWF: RCo/kg] for VWF)
Time Frame: 96 hours after treatment
Pharmacokinetic parameter
96 hours after treatment

Secondary Outcome Measures

Outcome Measure
Measure Description
Time Frame
Change in bleeding severity class
Time Frame: 24 hours after treatment
The study's secondary endpoint will be any change in consensus definitions in Common Terminology Criteria for Adverse Events (CTCAE) version 5.0 bleeding class 24 hours after treatment with Vonvendi.
24 hours after treatment
Change in bleeding/drain output volume from existing surgical drains
Time Frame: 24 hours after treatment
Change in total amount of bleeding/output from existing surgical drains will be a secondary study outcome.
24 hours after treatment

Collaborators and Investigators

This is where you will find people and organizations involved with this study.

Investigators

  • Principal Investigator: Michael Mazzeffi, MD, UVA

Publications and helpful links

The person responsible for entering information about the study voluntarily provides these publications. These may be about anything related to the study.

Study record dates

These dates track the progress of study record and summary results submissions to ClinicalTrials.gov. Study records and reported results are reviewed by the National Library of Medicine (NLM) to make sure they meet specific quality control standards before being posted on the public website.

Study Major Dates

Study Start (Actual)

October 3, 2024

Primary Completion (Estimated)

December 31, 2026

Study Completion (Estimated)

February 28, 2027

Study Registration Dates

First Submitted

September 21, 2023

First Submitted That Met QC Criteria

November 3, 2023

First Posted (Actual)

November 7, 2023

Study Record Updates

Last Update Posted (Actual)

February 5, 2026

Last Update Submitted That Met QC Criteria

February 2, 2026

Last Verified

February 1, 2026

More Information

Terms related to this study

Plan for Individual participant data (IPD)

Plan to Share Individual Participant Data (IPD)?

NO

Drug and device information, study documents

Studies a U.S. FDA-regulated drug product

Yes

Studies a U.S. FDA-regulated device product

No

product manufactured in and exported from the U.S.

No

This information was retrieved directly from the website clinicaltrials.gov without any changes. If you have any requests to change, remove or update your study details, please contact register@clinicaltrials.gov. As soon as a change is implemented on clinicaltrials.gov, this will be updated automatically on our website as well.

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