Clinical trial NCT00799396: Determining Genetic Role in Treatment Response to Anti-Platelet Interventions (The PAPI Study)
Official title: Pharmacogenomics of Anti-Platelet Interventions (The PAPI Study)
Study type: INTERVENTIONAL
Overall status: COMPLETED
Phase: PHASE4
Conditions: Platelet Aggregation Inhibitors
Coronary Heart Disease
Lead sponsor: University of Maryland, Baltimore
Sponsor class: OTHER
Collaborators: name: National Institute of General Medical Sciences (NIGMS)
name: National Heart, Lung, and Blood Institute (NHLBI)
First posted: 2008-11-27
Enrollment: 682
Sex: ALL
Minimum age (years): 20
Standard ages: ADULT
OLDER_ADULT
Accepts healthy volunteers: yes
Allocation: NA
Intervention model: SINGLE_GROUP
Primary purpose: TREATMENT

Brief summary: 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.

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.

Eligibility criteria: 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

Primary outcomes:
measure: Changes in Platelet Function in Response to Clopidogrel
timeFrame: Measured at baseline, and after clopidogrel treatment
measure: Changes in Platelet Function in Response to Clopidogrel Plus Aspirin
timeFrame: Measured at baseline, and after clopidogrel plus aspirin treatment
Secondary outcomes:
Other outcomes:
Locations:
city: Lancaster
country: United States
facility: Amish Research Clinic
state: Pennsylvania
Study officials:
affiliation: University of Maryland, Baltimore
name: Alan R. Shuldiner, MD
role: PRINCIPAL_INVESTIGATOR
References:
citation: Shuldiner AR, O'Connell JR, Bliden KP, Gandhi A, Ryan K, Horenstein RB, Damcott CM, Pakyz R, Tantry US, Gibson Q, Pollin TI, Post W, Parsa A, Mitchell BD, Faraday N, Herzog W, Gurbel PA. Association of cytochrome P450 2C19 genotype with the antiplatelet effect and clinical efficacy of clopidogrel therapy. JAMA. 2009 Aug 26;302(8):849-57. doi: 10.1001/jama.2009.1232.
citation: Bozzi LM, Mitchell BD, Lewis JP, Ryan KA, Herzog WR, O'Connell JR, Horenstein RB, Shuldiner AR, Yerges-Armstrong LM. The Pharmacogenomics of Anti-Platelet Intervention (PAPI) Study: Variation in Platelet Response to Clopidogrel and Aspirin. Curr Vasc Pharmacol. 2016;14(1):116-24. doi: 10.2174/1570161113666150916094829.
citation: Lewis JP, Ryan K, O'Connell JR, Horenstein RB, Damcott CM, Gibson Q, Pollin TI, Mitchell BD, Beitelshees AL, Pakzy R, Tanner K, Parsa A, Tantry US, Bliden KP, Post WS, Faraday N, Herzog W, Gong Y, Pepine CJ, Johnson JA, Gurbel PA, Shuldiner AR. Genetic variation in PEAR1 is associated with platelet aggregation and cardiovascular outcomes. Circ Cardiovasc Genet. 2013 Apr;6(2):184-92. doi: 10.1161/CIRCGENETICS.111.964627. Epub 2013 Feb 7.
citation: Lewis JP, Horenstein RB, Ryan K, O'Connell JR, Gibson Q, Mitchell BD, Tanner K, Chai S, Bliden KP, Tantry US, Peer CJ, Figg WD, Spencer SD, Pacanowski MA, Gurbel PA, Shuldiner AR. The functional G143E variant of carboxylesterase 1 is associated with increased clopidogrel active metabolite levels and greater clopidogrel response. Pharmacogenet Genomics. 2013 Jan;23(1):1-8. doi: 10.1097/FPC.0b013e32835aa8a2.
citation: Lewis JP, Fisch AS, Ryan K, O'Connell JR, Gibson Q, Mitchell BD, Shen H, Tanner K, Horenstein RB, Pakzy R, Tantry US, Bliden KP, Gurbel PA, Shuldiner AR. Paraoxonase 1 (PON1) gene variants are not associated with clopidogrel response. Clin Pharmacol Ther. 2011 Oct;90(4):568-74. doi: 10.1038/clpt.2011.194. Epub 2011 Aug 31.
citation: Lewis JP, Stephens SH, Horenstein RB, O'Connell JR, Ryan K, Peer CJ, Figg WD, Spencer SD, Pacanowski MA, Mitchell BD, Shuldiner AR. The CYP2C19*17 variant is not independently associated with clopidogrel response. J Thromb Haemost. 2013 Sep;11(9):1640-6. doi: 10.1111/jth.12342.
citation: Bergmeijer TO, Reny JL, Pakyz RE, Gong L, Lewis JP, Kim EY, Aradi D, Fernandez-Cadenas I, Horenstein RB, Lee MTM, Whaley RM, Montaner J, Gensini GF, Cleator JH, Chang K, Holmvang L, Hochholzer W, Roden DM, Winter S, Altman RB, Alexopoulos D, Kim HS, Dery JP, Gawaz M, Bliden K, Valgimigli M, Marcucci R, Campo G, Schaeffeler E, Dridi NP, Wen MS, Shin JG, Simon T, Fontana P, Giusti B, Geisler T, Kubo M, Trenk D, Siller-Matula JM, Ten Berg JM, Gurbel PA, Hulot JS, Mitchell BD, Schwab M, Ritchie MD, Klein TE, Shuldiner AR; ICPC Investigators. Genome-wide and candidate gene approaches of clopidogrel efficacy using pharmacodynamic and clinical end points-Rationale and design of the International Clopidogrel Pharmacogenomics Consortium (ICPC). Am Heart J. 2018 Apr;198:152-159. doi: 10.1016/j.ahj.2017.12.010. Epub 2017 Dec 17.
citation: Salimi S, Lewis JP, Yerges-Armstrong LM, Mitchell BD, Saeed F, O'Connell JR, Perry JA, Ryan KA, Shuldiner AR, Parsa A. Clopidogrel Improves Skin Microcirculatory Endothelial Function in Persons With Heightened Platelet Aggregation. J Am Heart Assoc. 2016 Oct 31;5(11):e003751. doi: 10.1161/JAHA.116.003751.