<clinical_study>
  <!-- This xml conforms to an XML Schema at:
    https://clinicaltrials.gov/ct2/html/images/info/public.xsd -->
  <required_header>
    <download_date>ClinicalTrials.gov processed this data on September 20, 2023</download_date>
    <link_text>Link to the current ClinicalTrials.gov record.</link_text>
    <url>https://clinicaltrials.gov/ct2/show/NCT04456608</url>
  </required_header>
  <id_info>
    <org_study_id>SITE00000212</org_study_id>
    <secondary_id>5P01GM116691</secondary_id>
    <nct_id>NCT04456608</nct_id>
  </id_info>
  <brief_title>Genetic and Dietary Predictors of Anti-platelet Response</brief_title>
  <official_title>Program on Genetic and Dietary Predictors of Drug Response in Rural and AI/AN Populations, Project-3, SA-3, Anti-platelet Response</official_title>
  <sponsors>
    <lead_sponsor>
      <agency>University of Washington</agency>
      <agency_class>Other</agency_class>
    </lead_sponsor>
    <collaborator>
      <agency>Southcentral Foundation</agency>
      <agency_class>Other</agency_class>
    </collaborator>
    <collaborator>
      <agency>University of Montana</agency>
      <agency_class>Other</agency_class>
    </collaborator>
    <collaborator>
      <agency>Oregon Health and Science University</agency>
      <agency_class>Other</agency_class>
    </collaborator>
    <collaborator>
      <agency>National Institute of General Medical Sciences (NIGMS)</agency>
      <agency_class>NIH</agency_class>
    </collaborator>
  </sponsors>
  <source>University of Washington</source>
  <oversight_info>
    <has_dmc>No</has_dmc>
    <is_fda_regulated_drug>Yes</is_fda_regulated_drug>
    <is_fda_regulated_device>No</is_fda_regulated_device>
    <is_us_export>Yes</is_us_export>
  </oversight_info>
  <brief_summary>
    <textblock>
      This study will investigate differences in platelet aggregation under basal and&#xD;
      aspirin-treated conditions in American Indian and Alaska Native people who have extreme&#xD;
      levels (low and high) of n-3 polyunsaturated fatty acids (n-3 PUFAs, EPA and DHA) in red&#xD;
      blood cell membranes. The study will also determine whether or not platelet aggregation under&#xD;
      the different conditions is modified by CYP4A11, CYP4F2, CYP4F11, PEAR1, and ACTN1 gene&#xD;
      variation.&#xD;
    </textblock>
  </brief_summary>
  <detailed_description>
    <textblock>
      Purpose: In this aim, the investigators will test the hypothesis that n-3 PUFAs modify&#xD;
      aspirin anti-platelet response, by measuring and comparing three different indicators of&#xD;
      aspirin response in individuals with extremely high and low RBC n-3 PUFA levels, under a&#xD;
      basal state and after 1-week of once a day aspirin treatment. The three indicators are: 1)&#xD;
      platelet TXB2 and 20-HETE concentrations; 2) platelet aggregation ex vivo (in response to&#xD;
      external stimuli); and 3) aspirin covalent adduct of COX-1. The investigators will also test&#xD;
      whether or not common variants in the CYP4A11, CYP4F2, CYP4F11, PEAR1 and ACTN1 genes are&#xD;
      associated with basal and aspirin-induced changes in platelet aggregation and, in an&#xD;
      exploratory analysis, modify the effects of n-3 PUFAs on aspirin response.&#xD;
&#xD;
      Procedures and Population: Investigators from the University of Montana, Southcentral&#xD;
      Foundation and Oregon Health &amp; Science University will recruit a total of 150 individuals (50&#xD;
      at each site) to participate in the study. At each performance site, the participants&#xD;
      recruited will represent 25 individuals with high and 25 individuals with low RBC n-3 PUFA&#xD;
      concentrations. After providing written consent, each study participant will be screened for&#xD;
      medical history and clinical lab testing to ensure good health and good liver, kidney and&#xD;
      blood test parameters. If found to be eligible, each participant will provide 12-hour fasted&#xD;
      (overnight) blood samples for isolation of plasma, platelets, lymphocytes, and red blood&#xD;
      cells. A separate blood sample will be collected into a citrate treated tube for platelet&#xD;
      aggregation testing using the PFA-100 platform. Isolated blood fractions will be stored at&#xD;
      -80°C.&#xD;
&#xD;
      After baseline sampling, each participant will be given six doses of aspirin (80 mg/day for 2&#xD;
      days) and instructed to take one dose daily at approximately 9 am. On the day after the last&#xD;
      aspirin dose, the participant will provide blood samples for repeated platelet aggregation&#xD;
      testing, platelet lipid analysis and measurement of aspirin covalent adduct to COX-1, and a&#xD;
      spot urine sample to confirm aspirin consumption by testing for salicylate. For 24 hours&#xD;
      prior to platelet aggregation testing, study participants will be asked to avoid foods that&#xD;
      could lead to spurious test results (eg, chocolate, tea, coffee, cola, red wine, beer,&#xD;
      tomato, grapes, grape juice, orange and cranberry juices, as well as traditional wild foods&#xD;
      that include berries, plant roots, plant greens etc).&#xD;
&#xD;
      Analytical Methods: Whole blood, point of care, platelet aggregation testing will be&#xD;
      performed using the automated PFA-100 instrument. Performance by research personnel will be&#xD;
      compared head-head to clinical testing services at each site, as a quality control measure.&#xD;
      In each test setting, the investigators will obtain results in duplicate for both&#xD;
      collagen/epinephrine and collagen/ADP cartridges. The investigators will also measure&#xD;
      platelet TXB2, 20-HETE and AA concentrations, by LC-MS/MS. In addition, the investigators&#xD;
      will develop and employ a method to quantify theaspirin covalent adduct of COX-1 in isolated&#xD;
      platelets from study participants.&#xD;
&#xD;
      Statistical Methods: For each study population, and subgroups with extreme RBC n-3 PUFA&#xD;
      phenotypes, the investigators will use linear regression models with robust standard errors&#xD;
      to identify significant differences in the mean absolute platelet aggregation test results&#xD;
      under basal and aspirin-treated conditions (primary outcome), as well as the&#xD;
      post-treatment-to-baseline change in platelet aggregation. Heterogeneity between pairs of&#xD;
      extreme phenotypes subgroups will be accounted for by including sex, age, BMI and platelet&#xD;
      count as covariates in the regression model. Sample size calculation for each performance&#xD;
      site (n = 25 per n-3 PUFA subgroup) was based on having power of at least 0.8 for detecting a&#xD;
      difference in mean platelet aggregation between the two extreme (0-10 and 90-100 percentiles)&#xD;
      n-3 PUFA subgroups under basal conditions, at a significance level of 0.05. As a secondary&#xD;
      level of analysis, for each subgroup of the extreme RBC n-3 PUFA phenotypes, the&#xD;
      investigators will also compare mean platelet TXB2 and 20-HETE concentrations under basal and&#xD;
      aspirin-treated conditions, as well as the post-treatment-to-baseline change. Finally, a&#xD;
      third level of analysis will involve testing each study population for a difference in the&#xD;
      extent of aspirin adduct to COX-1 between groups with extreme RBC n-3 PUFA phenotypes. The&#xD;
      investigators will test for associations between platelet aggregation test results and&#xD;
      biochemical measures of platelet activation, each study population separately and in&#xD;
      aggregate.&#xD;
&#xD;
      The investigators will use linear regression models to test for an association between common&#xD;
      CYP4A11,CYP4F2, CYP4F11, PEAR1 and ACTN1 genotypes and the mean absolute platelet aggregation&#xD;
      test results under basal and aspirin-treated conditions, as well as the&#xD;
      post-treatment-to-baseline change in platelet aggregation. In an exploratory analysis, the&#xD;
      investigators will apply Linear Mixed Effects (LME) models to the combined pre- and&#xD;
      post-treatment dataset to test for associations with n-3 PUFAs group and drug effects, as&#xD;
      well as to identify any modifications of those effects by CYP4A11, CYP4F2, CYP4F11, PEAR1 and&#xD;
      ACTN1 variation by including and testing for significant interaction effects in the models.&#xD;
      The investigators will include random effects in the LME to account for potential&#xD;
      heterogeneity in each of the populations.&#xD;
    </textblock>
  </detailed_description>
  <overall_status>Active, not recruiting</overall_status>
  <start_date type="Actual">August 1, 2016</start_date>
  <completion_date type="Anticipated">July 31, 2023</completion_date>
  <primary_completion_date type="Anticipated">July 31, 2023</primary_completion_date>
  <phase>Phase 4</phase>
  <study_type>Interventional</study_type>
  <has_expanded_access>No</has_expanded_access>
  <study_design_info>
    <allocation>N/A</allocation>
    <intervention_model>Single Group Assignment</intervention_model>
    <intervention_model_description>In this study we will recruit individuals who have previously been determined to have low or high RBC n-3 PUFA content and test platelet function at baseline and after 2-day aspirin treatment.</intervention_model_description>
    <primary_purpose>Basic Science</primary_purpose>
    <masking>None (Open Label)</masking>
  </study_design_info>
  <primary_outcome>
    <measure>PFA-100 Platelet Aggregation Test</measure>
    <time_frame>Single 9 am blood sample on day 3 of study</time_frame>
    <description>Citrated blood samples will be treated with collagen/epinephrine and collagen/ADP and the time to reach an aggregation endpoint will be measured.</description>
  </primary_outcome>
  <secondary_outcome>
    <measure>Platelet TBX2 concentration</measure>
    <time_frame>Single 9 am blood sample on day 3 of study</time_frame>
    <description>Platelet TBX2 concentration</description>
  </secondary_outcome>
  <secondary_outcome>
    <measure>Platelet 20-HETE concentration</measure>
    <time_frame>Single 9 am blood sample on day 3 of study</time_frame>
    <description>Platelet 20-HETE concentration</description>
  </secondary_outcome>
  <number_of_arms>1</number_of_arms>
  <enrollment type="Anticipated">150</enrollment>
  <condition>Platelet Function</condition>
  <arm_group>
    <arm_group_label>Low and High n-3 PUFA</arm_group_label>
    <arm_group_type>Experimental</arm_group_type>
    <description>Individuals with low or high n-3 PUFA RBC concentration will be given aspirin (81 mg of aspirin once a day, for 6 days)</description>
  </arm_group>
  <intervention>
    <intervention_type>Drug</intervention_type>
    <intervention_name>Aspirin</intervention_name>
    <description>Low and high n-3 PUFA participants will receive 81-mg aspirin once a day, for 6 days.</description>
    <arm_group_label>Low and High n-3 PUFA</arm_group_label>
  </intervention>
  <eligibility>
    <criteria>
      <textblock>
        Inclusion Criteria:&#xD;
&#xD;
          1. Participants with no history of significant medical conditions including cardiac,&#xD;
             pulmonary, hepatic, gastrointestinal, or renal disease, or HIV.&#xD;
&#xD;
          2. Participants will be males or females, 18 years or older.&#xD;
&#xD;
          3. Participants will be self-identified as: Yup'ik or Cup'ik (YK-Delta), AI/AN (SCF), or&#xD;
             a member of the Confederated Salish and Kootenai Tribe (Flathead Reservation).&#xD;
&#xD;
          4. Participants must read and understand English or Yup'ik.&#xD;
&#xD;
          5. Participants must be able to provide informed consent.&#xD;
&#xD;
        Exclusion Criteria:&#xD;
&#xD;
          1. Participants with any significant chronic medical condition, including cardiac,&#xD;
             pulmonary, hepatic, gastrointestinal, or renal disease, or HIV.&#xD;
&#xD;
          2. Participants less than 18 yrs of age.&#xD;
&#xD;
          3. Participants unable to read and understand English or Yup'ik.&#xD;
&#xD;
          4. Participants unable to provide informed consent.&#xD;
&#xD;
          5. Recent (within 2 weeks) use of aspirin, NSAIDs, antihistamines, or any prescription&#xD;
             anticoagulant drug such as warfarin.&#xD;
      </textblock>
    </criteria>
    <gender>All</gender>
    <minimum_age>18 Years</minimum_age>
    <maximum_age>N/A</maximum_age>
    <healthy_volunteers>Accepts Healthy Volunteers</healthy_volunteers>
  </eligibility>
  <overall_official>
    <last_name>Kenneth E Thummel, Ph.D.</last_name>
    <role>Principal Investigator</role>
    <affiliation>University of Washington</affiliation>
  </overall_official>
  <location>
    <facility>
      <name>Southcentral Foundation</name>
      <address>
        <city>Anchorage</city>
        <state>Alaska</state>
        <zip>99508</zip>
        <country>United States</country>
      </address>
    </facility>
  </location>
  <location>
    <facility>
      <name>University of Montana</name>
      <address>
        <city>Missoula</city>
        <state>Montana</state>
        <zip>59812</zip>
        <country>United States</country>
      </address>
    </facility>
  </location>
  <location>
    <facility>
      <name>Oregon Health &amp; Sciences University</name>
      <address>
        <city>Portland</city>
        <state>Oregon</state>
        <zip>97239</zip>
        <country>United States</country>
      </address>
    </facility>
  </location>
  <location_countries>
    <country>United States</country>
  </location_countries>
  <verification_date>June 2022</verification_date>
  <study_first_submitted>June 29, 2020</study_first_submitted>
  <study_first_submitted_qc>June 29, 2020</study_first_submitted_qc>
  <study_first_posted type="Actual">July 2, 2020</study_first_posted>
  <last_update_submitted>June 9, 2022</last_update_submitted>
  <last_update_submitted_qc>June 9, 2022</last_update_submitted_qc>
  <last_update_posted type="Actual">June 13, 2022</last_update_posted>
  <responsible_party>
    <responsible_party_type>Principal Investigator</responsible_party_type>
    <investigator_affiliation>University of Washington</investigator_affiliation>
    <investigator_full_name>Kenneth Thummel</investigator_full_name>
    <investigator_title>Professor: Pharmaceutics</investigator_title>
  </responsible_party>
  <intervention_browse>
    <!-- CAUTION:  The following MeSH terms are assigned with an imperfect algorithm            -->
    <mesh_term>Aspirin</mesh_term>
  </intervention_browse>
  <!-- Results have not yet been posted for this study                                          -->
</clinical_study>


download date: ClinicalTrials.gov processed this data on September 20, 2023
link text: Link to the current ClinicalTrials.gov record.
url: https://clinicaltrials.gov/ct2/show/NCT04456608
org study id: SITE00000212
secondary id: 5P01GM116691
nct id: NCT04456608
lead sponsor: 
collaborator: 
collaborator: 
collaborator: 
collaborator: 
has dmc: No
is fda regulated drug: Yes
is fda regulated device: No
is us export: Yes
This study will investigate differences in platelet aggregation under basal and
      aspirin-treated conditions in American Indian and Alaska Native people who have extreme
      levels (low and high) of n-3 polyunsaturated fatty acids (n-3 PUFAs, EPA and DHA) in red
      blood cell membranes. The study will also determine whether or not platelet aggregation under
      the different conditions is modified by CYP4A11, CYP4F2, CYP4F11, PEAR1, and ACTN1 gene
      variation.
Purpose: In this aim, the investigators will test the hypothesis that n-3 PUFAs modify
      aspirin anti-platelet response, by measuring and comparing three different indicators of
      aspirin response in individuals with extremely high and low RBC n-3 PUFA levels, under a
      basal state and after 1-week of once a day aspirin treatment. The three indicators are: 1)
      platelet TXB2 and 20-HETE concentrations; 2) platelet aggregation ex vivo (in response to
      external stimuli); and 3) aspirin covalent adduct of COX-1. The investigators will also test
      whether or not common variants in the CYP4A11, CYP4F2, CYP4F11, PEAR1 and ACTN1 genes are
      associated with basal and aspirin-induced changes in platelet aggregation and, in an
      exploratory analysis, modify the effects of n-3 PUFAs on aspirin response.

      Procedures and Population: Investigators from the University of Montana, Southcentral
      Foundation and Oregon Health & Science University will recruit a total of 150 individuals (50
      at each site) to participate in the study. At each performance site, the participants
      recruited will represent 25 individuals with high and 25 individuals with low RBC n-3 PUFA
      concentrations. After providing written consent, each study participant will be screened for
      medical history and clinical lab testing to ensure good health and good liver, kidney and
      blood test parameters. If found to be eligible, each participant will provide 12-hour fasted
      (overnight) blood samples for isolation of plasma, platelets, lymphocytes, and red blood
      cells. A separate blood sample will be collected into a citrate treated tube for platelet
      aggregation testing using the PFA-100 platform. Isolated blood fractions will be stored at
      -80°C.

      After baseline sampling, each participant will be given six doses of aspirin (80 mg/day for 2
      days) and instructed to take one dose daily at approximately 9 am. On the day after the last
      aspirin dose, the participant will provide blood samples for repeated platelet aggregation
      testing, platelet lipid analysis and measurement of aspirin covalent adduct to COX-1, and a
      spot urine sample to confirm aspirin consumption by testing for salicylate. For 24 hours
      prior to platelet aggregation testing, study participants will be asked to avoid foods that
      could lead to spurious test results (eg, chocolate, tea, coffee, cola, red wine, beer,
      tomato, grapes, grape juice, orange and cranberry juices, as well as traditional wild foods
      that include berries, plant roots, plant greens etc).

      Analytical Methods: Whole blood, point of care, platelet aggregation testing will be
      performed using the automated PFA-100 instrument. Performance by research personnel will be
      compared head-head to clinical testing services at each site, as a quality control measure.
      In each test setting, the investigators will obtain results in duplicate for both
      collagen/epinephrine and collagen/ADP cartridges. The investigators will also measure
      platelet TXB2, 20-HETE and AA concentrations, by LC-MS/MS. In addition, the investigators
      will develop and employ a method to quantify theaspirin covalent adduct of COX-1 in isolated
      platelets from study participants.

      Statistical Methods: For each study population, and subgroups with extreme RBC n-3 PUFA
      phenotypes, the investigators will use linear regression models with robust standard errors
      to identify significant differences in the mean absolute platelet aggregation test results
      under basal and aspirin-treated conditions (primary outcome), as well as the
      post-treatment-to-baseline change in platelet aggregation. Heterogeneity between pairs of
      extreme phenotypes subgroups will be accounted for by including sex, age, BMI and platelet
      count as covariates in the regression model. Sample size calculation for each performance
      site (n = 25 per n-3 PUFA subgroup) was based on having power of at least 0.8 for detecting a
      difference in mean platelet aggregation between the two extreme (0-10 and 90-100 percentiles)
      n-3 PUFA subgroups under basal conditions, at a significance level of 0.05. As a secondary
      level of analysis, for each subgroup of the extreme RBC n-3 PUFA phenotypes, the
      investigators will also compare mean platelet TXB2 and 20-HETE concentrations under basal and
      aspirin-treated conditions, as well as the post-treatment-to-baseline change. Finally, a
      third level of analysis will involve testing each study population for a difference in the
      extent of aspirin adduct to COX-1 between groups with extreme RBC n-3 PUFA phenotypes. The
      investigators will test for associations between platelet aggregation test results and
      biochemical measures of platelet activation, each study population separately and in
      aggregate.

      The investigators will use linear regression models to test for an association between common
      CYP4A11,CYP4F2, CYP4F11, PEAR1 and ACTN1 genotypes and the mean absolute platelet aggregation
      test results under basal and aspirin-treated conditions, as well as the
      post-treatment-to-baseline change in platelet aggregation. In an exploratory analysis, the
      investigators will apply Linear Mixed Effects (LME) models to the combined pre- and
      post-treatment dataset to test for associations with n-3 PUFAs group and drug effects, as
      well as to identify any modifications of those effects by CYP4A11, CYP4F2, CYP4F11, PEAR1 and
      ACTN1 variation by including and testing for significant interaction effects in the models.
      The investigators will include random effects in the LME to account for potential
      heterogeneity in each of the populations.
allocation: N/A
intervention model: Single Group Assignment
intervention model description: In this study we will recruit individuals who have previously been determined to have low or high RBC n-3 PUFA content and test platelet function at baseline and after 2-day aspirin treatment.
primary purpose: Basic Science
masking: None (Open Label)
measure: PFA-100 Platelet Aggregation Test
time frame: Single 9 am blood sample on day 3 of study
description: Citrated blood samples will be treated with collagen/epinephrine and collagen/ADP and the time to reach an aggregation endpoint will be measured.
measure: Platelet TBX2 concentration
time frame: Single 9 am blood sample on day 3 of study
description: Platelet TBX2 concentration
measure: Platelet 20-HETE concentration
time frame: Single 9 am blood sample on day 3 of study
description: Platelet 20-HETE concentration
arm group label: Low and High n-3 PUFA
arm group type: Experimental
description: Individuals with low or high n-3 PUFA RBC concentration will be given aspirin (81 mg of aspirin once a day, for 6 days)
intervention type: Drug
intervention name: Aspirin
description: Low and high n-3 PUFA participants will receive 81-mg aspirin once a day, for 6 days.
arm group label: Low and High n-3 PUFA
criteria: 
gender: All
minimum age: 18 Years
maximum age: N/A
healthy volunteers: Accepts Healthy Volunteers
last name: Kenneth E Thummel, Ph.D.
role: Principal Investigator
affiliation: University of Washington
facility: 
facility: 
facility: 
country: United States
responsible party type: Principal Investigator
investigator affiliation: University of Washington
investigator full name: Kenneth Thummel
investigator title: Professor: Pharmaceutics
mesh term: Aspirin