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HealthyNCT01520402

Genetic Response to Warfarin in Healthy Subjects

A study testing Warfarin in people with Healthy, run by Icahn School of Medicine at Mount Sinai at 1 site in United States.

Completed

Finished. The study has ended and is not enrolling. Results may be posted on the official record.

Official record
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Trial summary

The purpose of this study is to determine the importance of genetic differences on individuals' response to warfarin in a group of healthy subjects. Warfarin is also known by the "trade name" Coumadin and is in a class of medications called anticoagulants or "blood thinners." Warfarin works by reducing the blood's… Read more about this study

Who is it for?
Ages 18 to 74 yearsHealthy volunteers can take part
Conditions the study is for
Healthy
What is being tested?
Warfarin
Could I receive a placebo?
No, everyone receives an active treatment
How many people
35 participants
Where
1 siteUnited States
Study dates
Jun 2009to May 2011
Phase
Interventional
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 18 to 74 years
  • All sexes
  • Healthy volunteers accepted
  • Adult, Older adult

Who may be able to join

  • Healthy adult (> 18 years old.) subjects not taking warfarin
  • Willing and able to grant written informed consent
  • Available in proximity to the Medical Center for the anticipated duration of data collection (approximately 3 weeks).
  • Pre-menopausal women required negative pregnancy test at study onset and willingness to abstain from sexual activity or use barrier contraception; oral contraceptives interfere with coumadin.

Who cannot join

  • Daily prescribed medications including (1) a medication known to interact with warfarin, based on interactions listed in Micromedex as moderate or severe, and probable or definite (as of study start date, Appendix A) (2) aspirin or clopidogrel, which may increase bleeding risk in combination with warfarin.
  • Recent therapy (within two weeks) with a medication known to interact with warfarin based on medication interactions listed in Micromedex
  • History of thrombotic disorder requiring anticoagulant therapy
  • Thrombophilia or coagulopathy, by history or screening coagulation profile with INR or PTT level > 2x the upper limit of normal
  • Family history of thrombophilia or coagulopathy; prisoners or wards of the state; scheduled elective surgery within one month
  • Active liver disease based on clinical history or serum transaminase levels > 2x the upper limit of normal
Show all 10Show fewer
  • Protein C or S Deficiency assessed on screening protein C and S activity profile
  • Age ≥ 75
  • Pre-menopausal women on oral contraception
  • Non-English speaking individuals

Trial locations and contacts

1 site in 1 country.

United States1 site
  • Mount Sinai School of Medicine

    New York, New York, 10029

Other trials in United States

About this study

Official title: Quantitative Pharmacogenomics of the Anticoagulant Response to Warfarin in Healthy Subjects

The purpose of this study is to determine the importance of genetic differences on individuals' response to warfarin in a group of healthy subjects. Warfarin is also known by the "trade name" Coumadin and is in a class of medications called anticoagulants or "blood thinners." Warfarin works by reducing the blood's ability to make clots. It is used to stop blood clots from forming or growing larger in your blood and blood vessels. Warfarin is prescribed for many conditions, including for people with certain types of irregular heartbeat, people with replacement or mechanical heart valves, people who have suffered a heart attack, people who have had orthopedic surgery, or who have a history of having blood clots. Warfarin is used to prevent or treat deep vein thrombosis (swelling and blood clot in a vein), pulmonary embolism (a blood clot in the lung), and strokes (a blood clot in the brain). Researchers have found that certain genes may affect how a person's body will break down or react to warfarin. If genetic information can help doctors better determine the best dose of warfarin before it is first given, this may help the doctors get patients to the correct levels of blood thinning and thereby reduce the risk of bleeding or the risk of developing a blood clot. The expectation of this study is that this information will ultimately improve warfarin therapy while lessening the risks associated with dosing errors. This study is considered investigational because the subjects are healthy and not being prescribed warfarin for clinical care.

Read the detailed description

Warfarin is a highly effective oral anticoagulant that is increasingly prescribed in the United States. It has a narrow therapeutic window, however, that represents an inherent limitation, such that insufficient and excessive levels of anticoagulation are associated with elevated risks of thrombosis and bleeding particularly frequent early in the initial dose-finding phase of therapy. Typically, anticoagulation is achieved through empiric dosing and titration with consideration of certain variables and frequent assessment of the international normalized ratio (INR). Despite these precautions, conventional dosing strategies are associated with therapeutic levels of anticoagulation only about half the time on treatment. Recently, genetic variants, specifically variations in the CYP2C9 and VKORC1 genes, have been identified that affect warfarin dose requirements, prompting the expectation that gene-based dosing strategies may maximize therapeutic efficacy while minimizing the risks associated with dosing errors. While the association between variation in these genes and differences in warfarin dose requirements has been identified, the specific contribution of allelic variation to the response to warfarin administration has not been thoroughly identified. The investigators therefore seek to assess the impact of allelic variation on warfarin dose-response relationships in a group of healthy subjects. The investigators hypothesize that genetic variation in the CYP2C9 and VKORC1 enzymes will result in differences in the warfarin dose-response relationships when accounting for non-genetic factors that can affect the pharmacokinetics of warfarin and its effect on coagulation.

Conditions
Healthy
Being tested
Warfarin
Keywords
Genetic Determinants of Warfarin Dose Variability

What participants receive

What participants receive. In a randomised study each person is assigned to one group by chance.

  • WarfarinDrug

    Also called anticoagulant, Coumadin

    Enrolled subjects on a fixed vitamin K diet followed a standard warfarin dosing algorithm with daily point-of-care INR checks to goal INR ≥ 2 for two consecutive days, then to baseline INR≤1.2 off warfarin. Genotyping for common and rare polymorphisms in CYP2C9, VKORC1, and CYP4F2 performed at study entry and unblinded at completion. Plasma Vitamin K and S-warfarin levels are obtained at goal INR ≥ 2 and study exit (INR ≤1.2 off warfarin).

Study groups in NCT01520402
Study groupRoleWhat they receive
WarfarinExperimentalHealthy subjects age 18-74 with no medical indication for warfarin therapy, who are free of medications and co-morbid medical conditions with the potential to interfere with warfarin metabolism, and who are willing to follow a fixed vitamin K diet (men 120 micrograms/day, women 90 micrograms/day) are included.
Receives: Drug: Warfarin

What is being measured

The primary outcome is the main question the study is designed to answer.

  1. Median Cumulative Therapeutic Warfarin Dose (Milligrams)Requirements by Genotype

    To assess the effect of genotype variants (CYP2C9 and VKORC1 -1639 G>A) on the anticoagulant response to warfarin, the primary outcome was the cumulative dose required to achieve an INR value in the usual clinical therapeutic range (>2.0) for two consecutive days.

    Measured: average of 2 - 13 days

  2. Median Cumulative Warfarin Dose Requirement by Genotype Category (CYP2C9 and VKORC1 -1639 G>A Combination)

    Subjects were also grouped into four categories based on CYP2C9 and VKORC1 genotype profile: Group 1 (CYP2C9 wild-type and VKORC1 wild-type), Group 2 (CYP2C9 wild-type and VKORC1 variant), Group 3 (CYP2C9 variant and VKORC1 wild-type), and Group 4 (CYP2C9 variant and VKORC1 variant). Median cumulative warfarin dose requirement was determined for each genotype category.

    Measured: 2-30 days

Secondary outcomes (2)
  1. Median Cumulative Warfarin Dose Requirements by CYP4F2 Genotype Status

    To assess the effect of CYP4F2 genotype variants on the anticoagulant response to warfarin.

    Measured: average of 2 - 30 days

  2. Explained Variation in Combined Therapeutic Warfarin Dose Models

    The proportion of variance (R^2) explained by each predictor was calculated using multivariate regression analysis and adjusted for age, gender and reported race, with outcome values logarithmically transformed. The study was powered to detect R^2 > 20%, and significance was accepted at p<0.05.

    Measured: average of 2 - 30 days

Timeline

From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.

  1. First posted30 Jan 2012 (estimated)
  2. Study startJun 2009
  3. Primary completionMay 2011
  4. Study completionMay 2011

Resources

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 N/A
Primary purpose
Basic science
Allocation
Not applicable
Intervention model
Single group
Masking
None (open label)
Enrolment
35 participants (actual)
IDs, dates and publications
ClinicalTrials.gov ID
NCT01520402
Sponsor's protocol ID
GCO 08-1442
Other IDs
HSM # 11-00577
Status last verified
Feb 2013
First submitted
18 Jan 2012
Last updated
12 Feb 2013
Data monitoring committee
Yes

Publications

  • Wysowski DK, Nourjah P, Swartz L. Bleeding complications with warfarin use: a prevalent adverse effect resulting in regulatory action. Arch Intern Med. 2007 Jul 9;167(13):1414-9. doi: 10.1001/archinte.167.13.1414.

    PubMed 17620536
  • Hirsh J, Fuster V, Ansell J, Halperin JL; American Heart Association/American College of Cardiology Foundation. American Heart Association/American College of Cardiology Foundation guide to warfarin therapy. J Am Coll Cardiol. 2003 May 7;41(9):1633-52. doi: 10.1016/s0735-1097(03)00416-9. No abstract available.

    PubMed 12742309
  • Budnitz DS, Pollock DA, Weidenbach KN, Mendelsohn AB, Schroeder TJ, Annest JL. National surveillance of emergency department visits for outpatient adverse drug events. JAMA. 2006 Oct 18;296(15):1858-66. doi: 10.1001/jama.296.15.1858.

    PubMed 17047216
  • Fihn SD, McDonell M, Martin D, Henikoff J, Vermes D, Kent D, White RH. Risk factors for complications of chronic anticoagulation. A multicenter study. Warfarin Optimized Outpatient Follow-up Study Group. Ann Intern Med. 1993 Apr 1;118(7):511-20. doi: 10.7326/0003-4819-118-7-199304010-00005.

    PubMed 8280198
  • Palareti G, Leali N, Coccheri S, Poggi M, Manotti C, D'Angelo A, Pengo V, Erba N, Moia M, Ciavarella N, Devoto G, Berrettini M, Musolesi S. Bleeding complications of oral anticoagulant treatment: an inception-cohort, prospective collaborative study (ISCOAT). Italian Study on Complications of Oral Anticoagulant Therapy. Lancet. 1996 Aug 17;348(9025):423-8. doi: 10.1016/s0140-6736(96)01109-9.

    PubMed 8709780
  • van Walraven C, Jennings A, Oake N, Fergusson D, Forster AJ. Effect of study setting on anticoagulation control: a systematic review and metaregression. Chest. 2006 May;129(5):1155-66. doi: 10.1378/chest.129.5.1155.

    PubMed 16685005
  • Aithal GP, Day CP, Kesteven PJ, Daly AK. Association of polymorphisms in the cytochrome P450 CYP2C9 with warfarin dose requirement and risk of bleeding complications. Lancet. 1999 Feb 27;353(9154):717-9. doi: 10.1016/S0140-6736(98)04474-2.

    PubMed 10073515
  • Rieder MJ, Reiner AP, Gage BF, Nickerson DA, Eby CS, McLeod HL, Blough DK, Thummel KE, Veenstra DL, Rettie AE. Effect of VKORC1 haplotypes on transcriptional regulation and warfarin dose. N Engl J Med. 2005 Jun 2;352(22):2285-93. doi: 10.1056/NEJMoa044503.

    PubMed 15930419
  • Sconce EA, Khan TI, Wynne HA, Avery P, Monkhouse L, King BP, Wood P, Kesteven P, Daly AK, Kamali F. The impact of CYP2C9 and VKORC1 genetic polymorphism and patient characteristics upon warfarin dose requirements: proposal for a new dosing regimen. Blood. 2005 Oct 1;106(7):2329-33. doi: 10.1182/blood-2005-03-1108. Epub 2005 Jun 9.

    PubMed 15947090
  • Wadelius M, Chen LY, Downes K, Ghori J, Hunt S, Eriksson N, Wallerman O, Melhus H, Wadelius C, Bentley D, Deloukas P. Common VKORC1 and GGCX polymorphisms associated with warfarin dose. Pharmacogenomics J. 2005;5(4):262-70. doi: 10.1038/sj.tpj.6500313.

    PubMed 15883587
  • Gage BF, Eby C, Johnson JA, Deych E, Rieder MJ, Ridker PM, Milligan PE, Grice G, Lenzini P, Rettie AE, Aquilante CL, Grosso L, Marsh S, Langaee T, Farnett LE, Voora D, Veenstra DL, Glynn RJ, Barrett A, McLeod HL. Use of pharmacogenetic and clinical factors to predict the therapeutic dose of warfarin. Clin Pharmacol Ther. 2008 Sep;84(3):326-31. doi: 10.1038/clpt.2008.10. Epub 2008 Feb 27.

    PubMed 18305455
  • International Warfarin Pharmacogenetics Consortium; Klein TE, Altman RB, Eriksson N, Gage BF, Kimmel SE, Lee MT, Limdi NA, Page D, Roden DM, Wagner MJ, Caldwell MD, Johnson JA. Estimation of the warfarin dose with clinical and pharmacogenetic data. N Engl J Med. 2009 Feb 19;360(8):753-64. doi: 10.1056/NEJMoa0809329.

    PubMed 19228618
  • Limdi NA, Wadelius M, Cavallari L, Eriksson N, Crawford DC, Lee MT, Chen CH, Motsinger-Reif A, Sagreiya H, Liu N, Wu AH, Gage BF, Jorgensen A, Pirmohamed M, Shin JG, Suarez-Kurtz G, Kimmel SE, Johnson JA, Klein TE, Wagner MJ; International Warfarin Pharmacogenetics Consortium. Warfarin pharmacogenetics: a single VKORC1 polymorphism is predictive of dose across 3 racial groups. Blood. 2010 May 6;115(18):3827-34. doi: 10.1182/blood-2009-12-255992. Epub 2010 Mar 4.

    PubMed 20203262
  • Wu AH. Use of genetic and nongenetic factors in warfarin dosing algorithms. Pharmacogenomics. 2007 Jul;8(7):851-61. doi: 10.2217/14622416.8.7.851.

    PubMed 18240910
  • Lubitz SA, Scott SA, Rothlauf EB, Agarwal A, Peter I, Doheny D, Van Der Zee S, Jaremko M, Yoo C, Desnick RJ, Halperin JL. Comparative performance of gene-based warfarin dosing algorithms in a multiethnic population. J Thromb Haemost. 2010 May;8(5):1018-26. doi: 10.1111/j.1538-7836.2010.03792.x. Epub 2010 Feb 2.

    PubMed 20128861

Questions about this trial

What is this clinical trial studying?

A study testing Warfarin in people with Healthy, run by Icahn School of Medicine at Mount Sinai 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 4 inclusion and 10 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 12 Feb 2013. 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.

Are results available for this study?

Yes. Results are posted in the registry (first posted 7 Feb 2013). 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?

Median Cumulative Therapeutic Warfarin Dose (Milligrams)Requirements by Genotype (time frame: average of 2 - 13 days). 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?

On the ClinicalTrials.gov record for NCT01520402, which also lists 38 linked publications.

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 12 Feb 2013.

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