Safety and Tolerability of Recombinant Von Willebrand Factor Concentrate in Adult ECMO Patients With Major Bleeding: A Phase I Study
概览
- 阶段
- 1 期
- 干预措施
- Recombinant von Willebrand Factor
- 疾病 / 适应症
- Bleeding Disorder
- 发起方
- University of Virginia
- 入组人数
- 12
- 试验地点
- 1
- 主要终点
- Serious Adverse Events
- 状态
- 招募中
- 最后更新
- 2个月前
概览
简要总结
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.
详细描述
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.
研究者
Michael Mazzeffi, MD
Professor of Anesthesiology
University of Virginia
入排标准
入选标准
- •Adult patients (18 years or greater)
- •On extracorporeal membrane oxygenation
- •Major bleeding defined by CTCAE class 3 or greater
- •Off systemic anticoagulation for at least 4 hours
排除标准
- •Platelet count less than 40 x 109/L
- •International normalized ratio\> 2.0
- •Fibrinogen less than 150 mg/dL
- •Current participation in another clinical trial (interventional)
- •Heparin induced thrombocytopenia (active)
- •Acute liver failure, as indicated by bilirubin \>20 mg/dL or new onset hepatic encephalopathy
- •Patient or legally authorized representative unable to give informed consent
- •Allergy to recombinant von Willebrand Factor or any component of the product based on prior exposure
- •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
- •Known congenital or acquired thrombophilia
研究组 & 干预措施
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.
干预措施: Recombinant von Willebrand Factor
结局指标
主要结局
Serious Adverse Events
时间窗: 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.
Area under the plasma concentration curve from zero to infinity (h × U/dL)
时间窗: 96 hours after treatment
Pharmacokinetic parameter
Plasma half-life (hours)
时间窗: 96 hours after treatment
Pharmacokinetic parameter
Mean residence time (hours)
时间窗: 96 hours after treatment
Pharmacokinetic parameter
Clearance (mL/kg per hour)
时间窗: 96 hours after treatment
Pharmacokinetic parameter
Volume at a steady state (dL/kg)
时间窗: 96 hours after treatment
Pharmacokinetic parameter
Maximum concentration (U/dL)
时间窗: 96 hours after treatment
Pharmacokinetic parameter
Time to maximum concentration (hours)
时间窗: 96 hours after treatment
Pharmacokinetic parameter
Incremental recovery ([U/dL]/[U VWF: RCo/kg] for VWF)
时间窗: 96 hours after treatment
Pharmacokinetic parameter
次要结局
- Change in bleeding severity class(24 hours after treatment)
- Change in bleeding/drain output volume from existing surgical drains(24 hours after treatment)