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Clinical Trial for Evaluation of Vermillion's Blood Test to Predict the Probability of Peripheral Artery Disease (PAD-001)

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. Identifier: NCT01336426
Recruitment Status : Completed
First Posted : April 15, 2011
Last Update Posted : December 17, 2013
Information provided by (Responsible Party):
Vermillion, Inc.

Brief Summary:


This study is to verify and validate PAD1 as a qualitative serum test which will combine the results of multiple assays into a single numeric result, to be determined by evaluation of the study data.

PAD1 is an automated software device (PADCalc) that incorporates specific and multiple biomarker values found in human blood, and generates a score (PAD1 score) using a fixed formula implemented within the PADCalc software. The PAD1 score is a result with a high or low probability of PAD.

PAD1 will be submitted to FDA as a 510(k) for in vitro diagnostic use in conjunction with clinical assessment, based on factors such as age, diabetes, smoking, and vascular laboratory tests (including the ABI), as an aid towards further evaluation of patients who meet the enrollment eligilbility criteria.

Eligibility It is indicated for women and men considered at risk for PAD who meet the following criteria: a history of smoking and/or diabetes and are age 50 years or older, or 70 years of age or older. PAD1 is an aid to further assess the likelihood of the presence of PAD when used in conjunction with clinical assessment and vascular laboratory tests.

Condition or disease
Peripheral Artery Disease

Detailed Description:

Peripheral artery disease (PAD) affects 8 to 12 million individuals in the United States and is also prevalent in Europe and Asia. A regional pilot study of community screening for PAD demonstrated that patient awareness of a PAD diagnosis was low, and was associated with atherosclerosis risk factors, antiplatelet therapy, and claudication treatment intensity. PAD has not emerged as a focus of public health efforts to improve quality of life, nor to decrease the associated cardiovascular ischemic risk. Smoking, diabetes, and age are the strongest risk factors for PAD. Smokers have a 2 to 6-fold increased likelihood of having PAD, and the risk of PAD increases in a dose-dependent manner with the duration and amount of smoking. Diabetes confers a 2 to 4-fold increased risk of having PAD. The prevalence of PAD increases as a function of age. Criqui et al showed that the prevalence of PAD in individuals under 60 years of age was about 2.5%, whereas the prevalence increased to over 20% in individuals over 75 years of age.

A study in smokers and diabetics 50 years of age or older, and in all those 70 years of age or older, identified in an outpatient, primary care clinic setting has shown that the prevalence is 29%. About half of the cases found were newly-identified PAD patients. Further, while 83% of those with a prior diagnosis of PAD were aware of their condition, only 49% of the primary-care physicians were aware that their patients had a diagnosis of PAD. Another study examined internal medicine physicians' approaches to PAD and found that only 37% reported taking histories for claudication, and only 26% evaluated the foot for ulcers.

PAD is as prevalent in women as in men. When symptomatic, PAD causes limb discomfort, tiredness, heaviness, cramping, or pain brought on by exertion and relieved by rest (i.e., intermittent claudication) and reduces functional capacity and quality of life. Classic claudication is only noted by 10-30% of patients and atypical leg discomfort occurs in 20-40%. Up to 50% of patients are asymptomatic. PAD1 is an in vitro diagnostic that provides a PAD1 score derived from multiple biomarkers in human plasma, serum, or whole blood, which predicts a low or high probability of the presence of PAD in patients at risk for PAD. A positive PAD1 score(above the cutoff), indicating a higher risk for PAD than expected in the general population, would then guide the physician to more aggressively determine the presence of PAD.

The preliminary studies have shown an association of four proposed biomarkers with ABI, and have demonstrated the construction of a PAD risk algorithm. This study is powered to test each of the four biomarkers and their interactions and develop the PAD1 risk score in the intended use population.

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Study Type : Observational
Actual Enrollment : 1033 participants
Observational Model: Case-Only
Time Perspective: Prospective
Official Title: Clinical Trial for Evaluation of Vermillion's Blood Test to Predict the Probability of Peripheral Artery Disease
Study Start Date : March 2011
Actual Primary Completion Date : August 2011
Actual Study Completion Date : August 2011

Resource links provided by the National Library of Medicine

Primary Outcome Measures :
  1. PAD1 will identify individuals with a higher risk of PAD. [ Time Frame: 1 month ]
    PAD1 will identify individuals with a higher risk of PAD in an at-risk population of individuals 70 years of age or older, or smokers and/or diabetics 50 years of age or older.

Secondary Outcome Measures :
  1. To demonstrate that PAD1 has predictive value for PAD when used as a combination result. [ Time Frame: 1 month ]

    To demonstrate that PAD1 has predictive value for PAD in combination with:

    • The Framingham Risk Score
    • The 5-Symptom Questionnaire for prediction of PAD (5-Q Sx)

Biospecimen Retention:   Samples Without DNA
Serum, Plasma and Frozen Red Blood Cells

Information from the National Library of Medicine

Choosing to participate in a study is an important personal decision. Talk with your doctor and family members or friends about deciding to join a study. To learn more about this study, you or your doctor may contact the study research staff using the contacts provided below. For general information, Learn About Clinical Studies.

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Ages Eligible for Study:   50 Years and older   (Adult, Older Adult)
Sexes Eligible for Study:   All
Accepts Healthy Volunteers:   No
Sampling Method:   Probability Sample
Study Population
Subjects that meet the inclusion/exclusion criteria from 10 primary care sites.

Inclusion Criteria:

Subject is one or more of the following:

  • ≥50 years old and subject-reported current or former history (<10 years) of smoking for a minimum of 10 pack years.
  • ≥50 years old and history of type 2 diabetes (meeting American Diabetes Association criteria) as documented in the medical record, or use of diabetes medications or diabetes-specific diet.
  • ≥70 years old. 2. Subject provides written informed consent to participate in this study. 3. Subject agrees to de-identified biorepository storage of own processed blood sample for future testing.

Exclusion Criteria:

  1. Significant hepatic or renal insufficiency, including either of the following:

    • Renal insufficiency or renal failure within the past 6 months, or creatinine >2.5 mg/dL within the past 6 months (if results available), or currently on dialysis.
    • Severe liver disease or any chronic hepatitis within the past 6 months, or AST and ALT >3xULN (upper limit of normal), or bilirubin >2xULN within the past 6 months (if results available).
  2. Active viral or bacterial infection or subject is currently taking an antibiotic or antiviral agent.
  3. Active inflammatory condition requiring treatment with systemic steroids or immune modulating therapy within the past 6 months.
  4. Active malignancy that requires active anti-neoplastic therapy (stable basal cell skin cancer is allowed; cancer being treated solely with hormonal therapy is allowed).

Information from the National Library of Medicine

To learn more about this study, you or your doctor may contact the study research staff using the contact information provided by the sponsor.

Please refer to this study by its identifier (NCT number): NCT01336426

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United States, Alabama
Coastal Clinical Research
Mobile, Alabama, United States, 36608
United States, California
Apex Research Institute
Santa Ana, California, United States, 92705
Radiant Research
Santa Rosa, California, United States, 95405
United States, Florida
Tampa Bay Medical Research, Inc.
Clearwater, Florida, United States, 33761
United States, Missouri
Center for Pharmaceutical Research
Kansas City, Missouri, United States, 64114
United States, New Mexico
Lovelace Scientific Research
Albuquerque, New Mexico, United States, 87108
United States, Ohio
Radiant Research
Columbus, Ohio, United States, 43212
United States, Rhode Island
Omega Clinical Research
Warwick, Rhode Island, United States, 02886
United States, Texas
Clinical Trials of Texas, Inc.
San Antonio, Texas, United States, 78229
United States, Virginia
National Clinical Research, Inc.
Richmond, Virginia, United States, 23294
Sponsors and Collaborators
Vermillion, Inc.
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Study Director: Eric T Fung, MD. PhD. Vermillion, Inc.
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Responsible Party: Vermillion, Inc. Identifier: NCT01336426    
Other Study ID Numbers: PAD-001
First Posted: April 15, 2011    Key Record Dates
Last Update Posted: December 17, 2013
Last Verified: December 2013
Keywords provided by Vermillion, Inc.:
Peripheral Artery Disease
Additional relevant MeSH terms:
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Peripheral Arterial Disease
Arterial Occlusive Diseases
Vascular Diseases
Cardiovascular Diseases
Peripheral Vascular Diseases