Determining Genetic Role in Treatment Response to Anti-Platelet Interventions (The PAPI Study)

February 22, 2022 updated by: Alan Shuldiner, University of Maryland, Baltimore

Pharmacogenomics of Anti-Platelet Interventions (The PAPI Study)

One of the most common ways for preventing coronary heart disease (CHD) is to take aspirin or clopidogrel. However, studies have shown that not all people respond to these medications. The variance in treatment response may be linked to genetics. This study will examine the effects of aspirin and clopidogrel in a population whose genes are well known in order to determine the role that genes play in treatment responses.

Study Overview

Status

Completed

Conditions

Intervention / Treatment

Detailed Description

CHD is the leading cause of death in the United States. Anti-platelet agents lessen platelet aggregation and are used commonly to prevent recurrent CHD events. Two of the most common anti-platelet agents are aspirin and clopidogrel. However, up to 25% to 30% of people do not respond to these medications. Evidence indicates that treatment response may be related to genetics. The purpose of this study is to determine specific gene variants that predict response to aspirin and clopidogrel therapy.

This study is part of a larger group of studies called the Pharmacogenomics Research Network (PGRN). Participants will include the Old Order Amish of Lancaster, Pennsylvania. They are well suited for genetic studies because they are a homogenous, closed, founder population. Participants will receive 300 mg of clopidogrel on the first day, then 75 mg of clopidogrel per day for the next 6 days. On the last day of clopidogrel treatment, participants will take a single dose of 324 mg aspirin. Participants will undergo platelet function tests before and after clopidogrel alone, and then again after taking clopidogrel plus aspirin. Using the gene variation profiles across the genome, researchers will analyze which genes correspond to treatment response.

Study Type

Interventional

Enrollment (Actual)

682

Phase

  • Phase 4

Contacts and Locations

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

Study Locations

  • United States
    • Pennsylvania
      • Lancaster, Pennsylvania, United States, 17601
        • Amish Research Clinic

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

20 years and older (Adult, Older Adult)

Accepts Healthy Volunteers

Yes

Genders Eligible for Study

All

Description

Inclusion Criteria:

  • Of Old Order Amish descent

Exclusion Criteria:

  • Currently pregnant or less than 6 months have passed since delivery
  • Has a history of a bleeding disorder or major spontaneous bleed, such as peptic ulcer, epistasis, or intracranial bleed
  • Has severe hypertension, defined by a blood pressure above 160/95 mm Hg, making it unethical not to recommend prompt treatment
  • Takes medications that would affect the outcome(s) to be measured and cannot willingly and safely, in the opinion of the treating physician and study physician, discontinue these medications for 1 week prior to protocol initiation
  • Is taking vitamins or other supplements and is unwilling to discontinue their use for at least 1 week prior to study
  • Has a coexisting malignancy
  • Has a creatinine level greater than 2.0 mg/dl, aspartate transaminase (AST) or alanine transaminase (ALT) greater than two times the upper limit of normal, hematocrit less than 32%, or a thyroid-stimulating hormone (TSH) less than 0.4 or greater than 5.5 mIU/L
  • Has a bleeding disorder or history of gastrointestinal bleeding or other major bleeding episode
  • Is currently taking aspirin, clopidogrel, or other anti-coagulant, such as warfarin, heparin, or GPIIb/IIIa antagonists, and have conditions that might place them at increased risk from withdrawal of these medications 14 days prior to protocol initiation, including history of unstable angina, heart attack, angioplasty (including stent placement), coronary artery bypass surgery, atrial fibrillation, stroke or transient ischemic attacks, diabetes, or deep vein thrombosis or other thrombosis
  • Has polycythemia, or thrombocytosis, defined by a platelet count greater than 500,000
  • Has thrombocytopenia, defined by a platelet count less than 75,000
  • Has had surgery within the last 6 months
  • Has an aspirin or clopidogrel allergy
  • Currently breast feeding

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: Overall Study
Participants will receive clopidogrel treatment alone, followed by clopidogrel plus aspirin treatment on the last day of treatment.
Drug: Clopidogrel
300 mg on first day, then 75 mg per day for the next 6 days
Drug: Aspirin
Single dose of 324 mg on the last day of clopidogrel treatment

What is the study measuring?

Primary Outcome Measures

Outcome Measure
Measure Description
Time Frame
Changes in Platelet Function in Response to Clopidogrel
Time Frame: Measured at baseline, and after clopidogrel treatment
Baseline minus post clopidogrel/pre-aspirin platelet rich plasma (PRP) maximum aggregation.
Measured at baseline, and after clopidogrel treatment
Changes in Platelet Function in Response to Clopidogrel Plus Aspirin
Time Frame: Measured at baseline, and after clopidogrel plus aspirin treatment
Baseline minus post clopidogrel/post-aspirin platelet rich plasma (PRP) maximum aggregation
Measured at baseline, and after clopidogrel plus aspirin treatment

Collaborators and Investigators

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

Sponsor

University of Maryland, Baltimore

Collaborators

National Heart, Lung, and Blood Institute (NHLBI)
National Institute of General Medical Sciences (NIGMS)

Investigators

  • Principal Investigator: Alan R. Shuldiner, MD, University of Maryland School of Medicine

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.

General Publications

Helpful Links

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

July 1, 2006

Primary Completion (Actual)

February 1, 2012

Study Completion (Actual)

February 1, 2012

Study Registration Dates

First Submitted

November 26, 2008

First Submitted That Met QC Criteria

November 26, 2008

First Posted (Estimate)

November 27, 2008

Study Record Updates

Last Update Posted (Actual)

February 24, 2022

Last Update Submitted That Met QC Criteria

February 22, 2022

Last Verified

February 1, 2022

More Information

Terms related to this study

Additional Relevant MeSH Terms

Other Study ID Numbers

  • HP-00043419
  • U01GM074518 (U.S. NIH Grant/Contract)
  • U01 HL074518-01

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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