Heart DiseasesPhase 4NCT03188705
CES1 Carriers in the PAPI Study
A Phase 4 study testing Clopidogrel and Aspirin in people with Heart Diseases and Coronary Disease, run by University of Maryland, Baltimore at 1 site in United States.
Trial summary
This study builds, in part, upon preliminary results generated as part of the Pharmacogenomics Anti-Platelet Intervention (PAPI) Study (NCT00799396). The purpose of this investigation is to assess the impact of genetic variation in the carboxylesterase 1 (CES1) on response to clopidogrel as well as dual antiplatelet… Read more about this study
- Who is it for?
- Ages 20 years and olderHealthy volunteers can take part
- Conditions the study is for
- Heart Diseases, Coronary Disease, Coronary Artery Disease
- What is being tested?
- Clopidogrel and Aspirin
- Could I receive a placebo?
- No, everyone receives an active treatment
- How many people
- 6 participants
- Where
- 1 siteUnited States
- Study dates
- 14 Oct 2019to 17 Jan 2020
- Phase
- Phase 4
- Are there results?
- Yes, posted in the registrySummary in the doctors' view
Key requirements
Who can take part, as listed by the sponsor. Only the study team can confirm whether you are eligible, so take this list to your doctor.
- Ages 20 years and older
- All sexes
- Healthy volunteers accepted
- Adult, Older adult
Who may be able to join
- Age 20 years or older
- Of Old Order Amish descent
Who cannot join
- Currently pregnant or less than 6 months have passed since delivery
- Currently breast feeding
- 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
- 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 use for at least 1 week prior to study
Show all 15Show fewer
- 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 anti-coagulants, such as warfarin, heparin, or GPIIb/IIIa antagonists, and have conditions that might place the participant at increased risk from withdrawal of these medications 14 days prior to protocol initiation
- 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
Trial locations and contacts
1 site in 1 country.
United States1 site
Amish Research Clinic
Lancaster, Pennsylvania, 17602
About this study
Official title: Enrichment of CES1 Carriers in the Pharmacogenomics Anti-Platelet Intervention Study
This study builds, in part, upon preliminary results generated as part of the Pharmacogenomics Anti-Platelet Intervention (PAPI) Study (NCT00799396). The purpose of this investigation is to assess the impact of genetic variation in the carboxylesterase 1 (CES1) on response to clopidogrel as well as dual antiplatelet therapy (i.e. clopidogrel and aspirin), as assessed by ex vivo platelet aggregometry, in healthy Amish individuals. The investigators hypothesize that participants who carry alleles that modify the activity or expression of CES1 will have altered response to clopidogrel as well as dual antiplatelet therapy.
- Conditions
- Heart Diseases, Coronary Disease, Coronary Artery Disease, Cardiovascular Diseases, Myocardial Ischemia, Artery Occlusion
- Being tested
- Clopidogrel, Aspirin
- Keywords
- pharmacogenetics, carboxylesterase, Personalized Medicine
- Medical subject headings
- Heart Diseases, Coronary Disease, Coronary Artery Disease, Cardiovascular Diseases, Myocardial Ischemia, Arterial Occlusive Diseases
What participants receive
What participants receive. In a randomised study each person is assigned to one group by chance.
ClopidogrelDrug
Also called Plavix
Participants will receive 300 mg of clopidogrel on the first day, then 75 mg per day for the next 6 days. Measures of pharmacodynamics will be assessed pre- and post-drug administration.
AspirinDrug
Participants will receive a single dose of 324 mg aspirin on the last day of clopidogrel administration.
| Study group | Role | What they receive |
|---|---|---|
| Overall Cohort | Experimental | Participants will receive clopidogrel treatment alone (300 mg loading dose followed by 75 mg/d for 6 days), followed by clopidogrel (75 mg) plus aspirin (324 mg) treatment on day 8. Receives: Drug: Clopidogrel; Drug: Aspirin |
What is being measured
The primary outcome is the main question the study is designed to answer.
Changes in Platelet Function in Response to Clopidogrel
Baseline minus post clopidogrel/pre-aspirin platelet rich plasma (PRP) maximum aggregation in response to ADP (20 ug/ml) or collagen (5 ug/ml). Maximum platelet aggregation is recorded by the platelet aggregometer as a percentage. Data shown below represent the maximum platelet aggregation value obtained at baseline (recorded as a percentage) minus the maximum platelet aggregation value obtained after clopidogrel administration but before aspirin administration (also recorded as percentage). Thus, values recorded below represent a percentage change.
Measured: Measured at baseline and after 8 days of clopidogrel treatment
Changes in Platelet Function in Response to Clopidogrel Plus Aspirin
Baseline minus post clopidogrel/post-aspirin platelet rich plasma (PRP) maximum aggregation in response to ADP (20 ug/ml) or collagen (5 ug/ml). Maximum platelet aggregation is recorded by the platelet aggregometer as a percentage. Data shown below represent the maximum platelet aggregation value obtained at baseline (recorded as a percentage) minus the maximum platelet aggregation value obtained after clopidogrel and aspirin administration (also recorded as percentage). Thus, values recorded below represent a percentage change.
Measured: Measured at baseline and after 8 days clopidogrel administration plus 1 day of aspirin treatment
Timeline
From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.
- First posted15 Jun 2017
- Study start14 Oct 2019
- Primary completion17 Jan 2020
- Study completion17 Jan 2020
Resources
- Official record on ClinicalTrials.govThe registry entry this page is built from, with its full change history.
- Posted resultsParticipant flow, outcome measures and adverse events reported by the sponsor.
- Other trials for Heart DiseasesStudies of the same condition, open and under way.
- What the trial phases meanHow a treatment moves from first tests in people to approval.
More details
For doctors and researchers: how the study is designed, who runs it, and its registry IDs.
Study design
- Study type
- Interventional
- Phase
- Phase 4
- Primary purpose
- Basic science
- Allocation
- Not applicable
- Intervention model
- Single group
- Model description
- The investigators will enroll up to 50 healthy Amish participants who have been identified through existing whole genome and exome sequencing along with bioinformatic approaches that have genetic variants that are predicted to significantly impact CES1 expression or catalytic function. Enrolled participants will undergo a two-stage intervention with clopidogrel (300 mg loading dose then 75 mg per day for the next 6 days), followed by clopidogrel (75 mg) plus aspirin 324 mg for 1 day. Platelet aggregation studies and other measures of platelet function will be performed before and after each intervention. In combination with previously collected data as part of the PAPI Study, the investigators will then characterize the impact of genetic variation in CES1 on clopidogrel and dual antiplatelet therapy response through single- and multi-variant association modeling.
- Masking
- None (open label)
- Enrolment
- 6 participants (actual)
Sponsor and investigators
- Lead sponsor
- University of Maryland, Baltimore
- Sponsor type
- University, hospital or other
- Responsible party
- Principal investigator, Braxton Mitchell, University of Maryland, Baltimore
- Investigators
- Braxton D Mitchell, PhD, Principal investigator, University of Maryland
IDs, dates and publications
- ClinicalTrials.gov ID
- NCT03188705
- Sponsor's protocol ID
- HP-00075567
- Status last verified
- May 2023
- First submitted
- 14 Jun 2017
- Last updated
- 31 Jul 2026
- Results posted
- Yes, on ClinicalTrials.gov
- Data monitoring committee
- No
- FDA-regulated drug
- Yes
- FDA-regulated device
- No
- Individual data sharing
- Yes: Yes It is possible that deidentified data will be deposited into large public databases as per NIH data sharing policies (e.g. dbGAP, PharmGKB). Data to be shared would include, but not limited to, anthropometric data, study outcome data, and relevant covariate data used in statistical models of association. It is anticipated that data would be available after the completion of the trial. The data will be obtained from the participants and the study-related research procedures.
Study at a glance
From the registry record, last updated by the sponsor on 31 Jul 2026. Recruitment status is as the sponsor reported it: confirm with the study team.
- Official title
- Enrichment of CES1 Carriers in the Pharmacogenomics Anti-Platelet Intervention Study
- ClinicalTrials.gov ID
- NCT03188705
- Acronym / sponsor ID
- HP-00075567
- Conditions
- Heart Diseases, Coronary Disease, Coronary Artery Disease, Cardiovascular Diseases, Myocardial Ischemia, Artery Occlusion
- Keywords
- pharmacogenetics, carboxylesterase, Personalized Medicine
- Phase
- Phase 4
- Study type
- Interventional
- Recruitment status
- Completed
- Enrolment
- 6 participants (actual)
- Lead sponsor
- University of Maryland, BaltimoreUniversity, hospital or other
- Study start
- 14 Oct 2019 (actual)
- Primary completion
- 17 Jan 2020 (actual)
- Study completion
- 17 Jan 2020 (actual)
- First posted
- 15 Jun 2017 (actual)
- Results
- Posted 15 Jun 2023
Clinical summary
The research question as the sponsor registered it. This describes what the study plans to test, not what it found.
This study builds, in part, upon preliminary results generated as part of the Pharmacogenomics Anti-Platelet Intervention (PAPI) Study (NCT00799396). The purpose of this investigation is to assess the impact of genetic variation in the carboxylesterase 1 (CES1) on response to clopidogrel as well as dual antiplatelet therapy (i.e. clopidogrel and aspirin), as assessed by ex vivo platelet aggregometry, in healthy Amish individuals. The investigators hypothesize that participants who carry alleles that modify the activity or expression of CES1 will have altered response to clopidogrel as well as dual antiplatelet therapy.
Study design
- Primary purpose
- Basic science
- Allocation
- Not applicable
- Intervention model
- Single group
- Masking
- None (open label)
- Number of arms
- 1
- Model description
- The investigators will enroll up to 50 healthy Amish participants who have been identified through existing whole genome and exome sequencing along with bioinformatic approaches that have genetic variants that are predicted to significantly impact CES1 expression or catalytic function. Enrolled participants will undergo a two-stage intervention with clopidogrel (300 mg loading dose then 75 mg per day for the next 6 days), followed by clopidogrel (75 mg) plus aspirin 324 mg for 1 day. Platelet aggregation studies and other measures of platelet function will be performed before and after each intervention. In combination with previously collected data as part of the PAPI Study, the investigators will then characterize the impact of genetic variation in CES1 on clopidogrel and dual antiplatelet therapy response through single- and multi-variant association modeling.
| Arm | Type | Receives |
|---|---|---|
| Overall Cohort | Experimental | Drug: Clopidogrel, Drug: AspirinParticipants will receive clopidogrel treatment alone (300 mg loading dose followed by 75 mg/d for 6 days), followed by clopidogrel (75 mg) plus aspirin (324 mg) treatment on day 8. |
Who may qualify
- Ages
- 20 years and older
- Sex
- All
- Healthy volunteers
- Accepted
- Age groups
- Adult, Older adult
Key inclusion criteria (2 listed)
- Age 20 years or older
- Of Old Order Amish descent
Key exclusion criteria (15 listed)
- Currently pregnant or less than 6 months have passed since delivery
- Currently breast feeding
- 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
- 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
Eligibility is decided by the study team after screening; this overview does not establish that a patient qualifies. Full inclusion and exclusion criteria.
Interventions
| Intervention | Type | Arms |
|---|---|---|
| ClopidogrelAlso: PlavixParticipants will receive 300 mg of clopidogrel on the first day, then 75 mg per day for the next 6 days. Measures of pharmacodynamics will be assessed pre- and post-drug administration. | Drug | Overall Cohort |
| AspirinParticipants will receive a single dose of 324 mg aspirin on the last day of clopidogrel administration. | Drug | Overall Cohort |
Primary outcome
Changes in Platelet Function in Response to Clopidogrel
Time frame: Measured at baseline and after 8 days of clopidogrel treatment
Baseline minus post clopidogrel/pre-aspirin platelet rich plasma (PRP) maximum aggregation in response to ADP (20 ug/ml) or collagen (5 ug/ml). Maximum platelet aggregation is recorded by the platelet aggregometer as a percentage. Data shown below represent the maximum platelet aggregation value obtained at baseline (recorded as a percentage) minus the maximum platelet aggregation value obtained after clopidogrel administration but before aspirin administration (also recorded as percentage). Thus, values recorded below represent a percentage change.
Changes in Platelet Function in Response to Clopidogrel Plus Aspirin
Time frame: Measured at baseline and after 8 days clopidogrel administration plus 1 day of aspirin treatment
Baseline minus post clopidogrel/post-aspirin platelet rich plasma (PRP) maximum aggregation in response to ADP (20 ug/ml) or collagen (5 ug/ml). Maximum platelet aggregation is recorded by the platelet aggregometer as a percentage. Data shown below represent the maximum platelet aggregation value obtained at baseline (recorded as a percentage) minus the maximum platelet aggregation value obtained after clopidogrel and aspirin administration (also recorded as percentage). Thus, values recorded below represent a percentage change.
Results and safety
Loading the posted results from ClinicalTrials.gov…
Research links
- Official record on ClinicalTrials.govLast updated by the sponsor 31 Jul 2026.
- Posted resultsParticipant flow, baseline, all outcome measures and adverse events.
- Individual participant dataSharing planned: Yes. Yes It is possible that deidentified data will be deposited into large public databases as per NIH data sharing policies (e.g. dbGAP, PharmGKB). Data to be shared would include, but not limited to, anthropometric data, study outcome data, and relevant covariate data used in statistical models of association. It is anticipated that data would be available after the completion of the trial. The data will be obtained from the participants and the study-related research procedures.
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Referral and contact
AzTrials does not enrol participants or take referrals. Contact the study team or a site listed below; they decide who can take part. This study is not recruiting at the moment.
Braxton D Mitchell, PhD principal investigator
University of Maryland
1 site in 1 country: see every site and its status.
Questions about this trial
What is this clinical trial studying?
A Phase 4 study testing Clopidogrel and Aspirin in people with Heart Diseases and Coronary Disease, run by University of Maryland, Baltimore at 1 site in United States.
The full registered description is in the About this study section and the official record.
Who may be eligible to take part?
The sponsor lists 2 inclusion and 15 exclusion criteria. Eligibility is decided by the study team after screening, so read the full criteria and contact a listed site.
Is this clinical trial currently recruiting?
The record says: finished, as of the sponsor's last update on 31 Jul 2026. Status can change between updates, so confirm with the study contact before making plans.
Where is the study taking place?
The record lists 1 site in United States. Whether a site is taking part right now should be confirmed with that site. See every site.
What are the possible benefits and risks?
They depend on the study and the treatment, and no study can promise a benefit. The study team explains the known risks during informed consent, before anyone joins; the record itself does not list them.
What does this phase mean?
Phase 4 studies take place after a treatment is approved, to learn more about its long-term benefits and risks in everyday use.
Not every study follows the same path, and some studies (observational studies, device studies) have no phase.
Are results available for this study?
Yes. Results are posted in the registry (first posted 15 Jun 2023). A summary is in the For doctors view, and the full results are on ClinicalTrials.gov.
How can a doctor refer a patient or contact the research team?
The record lists no contact. The official record names the sponsor, who can be asked directly. AzTrials does not enrol participants or take referrals.
What does the primary outcome measure?
Changes in Platelet Function in Response to Clopidogrel (time frame: Measured at baseline and after 8 days of clopidogrel treatment). The study lists 2 primary outcomes in all. It is what the study was designed to measure, not a finding.
Where can I read the original study information?
Does a listing mean the treatment is approved or proven to work?
No. A listing means the study is registered. It does not show that the treatment is safe, works, or is approved by a regulator.
How often is this information updated?
AzTrials copies changed records from ClinicalTrials.gov every night and reloads the whole registry every week. The sponsor last updated this record on 31 Jul 2026.