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Vorapaxar and Lower Extremity Bypass Grafts

The safety and scientific validity of this study is the responsibility of the study sponsor and investigators. Listing a study does not mean it has been evaluated by the U.S. Federal Government. Read our disclaimer for details.
 
ClinicalTrials.gov Identifier: NCT02975583
Recruitment Status : Withdrawn (We could not secure adequate medication)
First Posted : November 29, 2016
Last Update Posted : January 25, 2018
Sponsor:
Collaborator:
Merck Sharp & Dohme Corp.
Information provided by (Responsible Party):
Joshua Beckman, Vanderbilt University

Tracking Information
First Submitted Date  ICMJE November 18, 2016
First Posted Date  ICMJE November 29, 2016
Last Update Posted Date January 25, 2018
Actual Study Start Date  ICMJE October 1, 2017
Actual Primary Completion Date January 10, 2018   (Final data collection date for primary outcome measure)
Current Primary Outcome Measures  ICMJE
 (submitted: November 22, 2016)
Bypass Graft Flow Mediated Vasodilation under Fasted Conditions using B-mode ultrasonography on Day 180 for each treatment condition. [ Time Frame: 6 Months ]
Ultrasonographic evaluation of the graft before and after sphygmomanometric cuff inflation on the calf is performed and the measure of interest is percent increase in vein graft diameter.
Original Primary Outcome Measures  ICMJE Same as current
Change History
Current Secondary Outcome Measures  ICMJE
 (submitted: November 28, 2016)
  • Change From Baseline in Flow Mediated Vasodilation (FMD) Under Fasted Condition on Day 180 [ Time Frame: baseline and day 180 for each treatment arm ] [ Time Frame: 6 Months ]
    Ultrasonographic evaluation of the graft before and after sphygmomanometric cuff inflation on the arm is performed and the measure of interest is percent increase in brachial artery diameter.
  • Platelet Activation blood testing [ Time Frame: 30 days ]
    The investigators will be measuring levels of platelet dilysyl-MDA cross-links 30 days after treatment initiation. Higher levels indicate more platelet activation.
  • Change in Six Minute Walk Test from Baseline to 1 year [ Time Frame: One year ]
    The distance walked in a 100 foot hallway in 6 minutes.
Original Secondary Outcome Measures  ICMJE
 (submitted: November 22, 2016)
  • Change From Baseline in Flow Mediated Vasodilation (FMD) Under Fasted Condition on Day 180 [ Time Frame: baseline and day 180 for each treatment arm ] [ Time Frame: 6 Months ]
    Ultrasonographic evaluation of the graft before and after sphygmomanometric cuff inflation on the arm is performed and the measure of interest is percent increase in brachial artery diameter.
  • Platelet Activation blood testing [ Time Frame: 30 days ]
    We will be measuring levels of platelet dilysyl-MDA cross-links 30 days after treatment initiation. Higher levels indicate more platelet activation.
  • Change in Six Minute Walk Test from Baseline to 1 year [ Time Frame: One year ]
    The distance walked in a 100 foot hallway in 6 minutes.
Current Other Pre-specified Outcome Measures Not Provided
Original Other Pre-specified Outcome Measures Not Provided
 
Descriptive Information
Brief Title  ICMJE Vorapaxar and Lower Extremity Bypass Grafts
Official Title  ICMJE A Double-blind, Randomized, Parallel Design Two Center Study to Compare the Effect of Vorapaxar vs. Placebo on Lower Extremity Vein Graft Maturation, Remodeling, and Function
Brief Summary There are no medical therapies indicated for reduction of limb ischemic events. Studies of dual-antiplatelet therapy with aspirin and clopidogrel versus aspirin alone (CASPAR) as well as studies of systemic anticoagulation (WAVE) have shown no benefit for either strategy in the reduction in limb vascular events. Surgical bypass grafting involves harvesting of the vein, warm ischemia with disruption of vaso vasorum, ischemia-reperfusion, and finally heightened hemodynamic stress in the new arterial environment. Vein grafts rapidly remodel in response to the increase in blood flow and pressure in an attempt to normalize them into physiological range. The investigators have previously identified 3 distinct temporal phases of the remodeling process: During the first 30 days following implantation is a critical period of luminal enlargement which appears to be an endothelium-independent process. The second phase occurs between 1 and 3 months and represents a period of stiffening of the vein graft indicating synthesis of fibrous proteins. The third period is referred to as biochemical remodeling wherein the vein recovers clinically measureable endothelial function. It is likely diabetes mellitus impacts each of these phases. TRA2°P-TIMI 50 demonstrated a reduction in acute limb ischemic (ALI) events (42% reduction) and urgent peripheral arterial revascularizations (35% reduction), a finding unique among medical therapies. While the temporal trend in reduction in ALI events occurred early and late after exposure suggestion an antithrombotic mechanism, the reduction in elective revascularization occurred later suggested beneficial effects beyond platelet inhibition. The purpose of this trial is to study the physiological impact of vorapaxar on lower extremity bypass graft maturation and function.
Detailed Description

Peripheral artery disease (PAD) is characterized by atherosclerotic occlusive disease of the lower extremities. More than 8 million Americans and 200 million people globally have PAD. Recent data reveal a prevalence of 15% in the MEDICARE population. In populations at risk, patients with a history of diabetes or cigarette smoking, the risk may rise as high as 30%. In addition to the heightened risk of myocardial infarction and stroke, PAD increases the risk of lower extremity claudication and critical limb ischemia. Lower extremity bypass grafting is an important method of restoring blood flow to the distal limb, reducing symptoms of claudication, and preventing amputation in patients with severe PAD.

Vorapaxar is a protease activated receptor (PAR)-1 antagonist that inhibits thrombin activation of the PAR-1 receptor. Vorapaxar has been FDA approved for patients with PAD to reduce the rate of cardiovascular death, MI, stroke, and urgent coronary revascularization. It is prohibited in patients with a previous stroke. In addition, patients treated with vorapaxar were noted to have a significant reduction in the rates of acute limb ischemia. This study will be a randomized, double blind, placebo-controlled randomized study of vorapaxar vs. placebo in 80 patients undergoing femoral-popliteal bypass grafting for Rutherford 3 - 5 disease.

Baseline visit: Informed consent will be signed. Vital signs will be taken and blood drawn fasting for baseline values.

First visit, pre-surgery: Blood will be drawn for platelet activation testing. A 6 minute walk test will be performed. Brachial artery reactivity testing will be performed. An ankle-brachial index will be performed.

30 days: Platelet testing will be performed. 90 days: Limited history and physical exam. 180 days: Limited history and exam, blood draw for biomarkers, brachial artery reactivity testing. Vein bypass graft reactivity testing.

360 days: 6 minute walk test and ankle brachial index will be performed.

Randomization: The Investigational Pharmacy will create a block randomization. Patients in the active treatment group will receive vorapaxar 2.08 mg daily or matching placebo. Treatment will continue for 1 year.

In addition, 20 healthy subjects to serve as a control population to define normal parameters during a single visit day. The healthy subjects will not be administered vorapaxar or placebo.

Study Type  ICMJE Interventional
Study Phase  ICMJE Phase 4
Study Design  ICMJE Allocation: Randomized
Intervention Model: Parallel Assignment
Masking: Quadruple (Participant, Care Provider, Investigator, Outcomes Assessor)
Primary Purpose: Other
Condition  ICMJE Peripheral Artery Disease
Intervention  ICMJE
  • Drug: Vorapaxar
    2.08 mg oral tablet daily
    Other Name: Zontivity
  • Drug: Placebos
    Placebo oral tablet daily
    Other Name: Placebo
Study Arms  ICMJE
  • Active Comparator: Experimental: Vorapaxar
    Drug: Vorapaxar 2.08 mg orally daily for a year Other name: Zontivity
    Intervention: Drug: Vorapaxar
  • Placebo Comparator: Placebo Comparator: Placebos
    Medication: Matching Placebo Daily tablet
    Intervention: Drug: Placebos
Publications * Not Provided

*   Includes publications given by the data provider as well as publications identified by ClinicalTrials.gov Identifier (NCT Number) in Medline.
 
Recruitment Information
Recruitment Status  ICMJE Withdrawn
Actual Enrollment  ICMJE
 (submitted: January 23, 2018)
0
Original Estimated Enrollment  ICMJE
 (submitted: November 22, 2016)
100
Actual Study Completion Date  ICMJE January 10, 2018
Actual Primary Completion Date January 10, 2018   (Final data collection date for primary outcome measure)
Eligibility Criteria  ICMJE

Inclusion Criteria:

  • Male or female, age 35 years or older
  • Atherosclerotic, infrainguinal PAD
  • Rutherford classes 3-5 planned for lower extremity bypass grafting
  • Adequate inflow into the index femoral artery
  • Adequate popliteal, tibial, or pedal revascularization target
  • Willing to comply with protocol, attend follow-up appointments, complete all study assessments, and provide informed consent

Exclusion Criteria:

  • Complete occlusion of the iliac artery
  • Aortoiliac occlusive disease or severe common femoral artery disease
  • Presence of a femoral, popliteal or tibial aneurysm of the index limb
  • Life expectancy less than 2 years
  • A vascular disease prognosis that includes an anticipated above ankle amputation on index limb within 4 weeks of index procedure
  • Renal dysfunction defined as MDRD eGFR ≤ 30ml/min/173 m2 at the time of screening
  • Currently on dialysis or history of a renal transplant
  • A documented hypercoagulable state
  • Nonatherosclerotic occlusive disease
  • Any prior infrainguinal revascularization
  • Current immunosuppressive medication, chemotherapy or radiation therapy
  • Absolute contraindication to iodinated contrast
  • Women who are pregnant
  • Women who are nursing
Sex/Gender  ICMJE
Sexes Eligible for Study: All
Ages  ICMJE 35 Years to 75 Years   (Adult, Older Adult)
Accepts Healthy Volunteers  ICMJE Yes
Contacts  ICMJE Contact information is only displayed when the study is recruiting subjects
Listed Location Countries  ICMJE Not Provided
Removed Location Countries  
 
Administrative Information
NCT Number  ICMJE NCT02975583
Other Study ID Numbers  ICMJE 161925
Has Data Monitoring Committee No
U.S. FDA-regulated Product
Studies a U.S. FDA-regulated Drug Product: No
Studies a U.S. FDA-regulated Device Product: No
Product Manufactured in and Exported from the U.S.: No
IPD Sharing Statement  ICMJE
Plan to Share IPD: No
Plan Description: There is no plan to share IPD at this time.
Responsible Party Joshua Beckman, Vanderbilt University
Study Sponsor  ICMJE Vanderbilt University
Collaborators  ICMJE Merck Sharp & Dohme Corp.
Investigators  ICMJE
Principal Investigator: Joshua A Beckman Vanderbilt University Medical Center
PRS Account Vanderbilt University Medical Center
Verification Date January 2018

ICMJE     Data element required by the International Committee of Medical Journal Editors and the World Health Organization ICTRP