The Clinical and Economic Impact of Pharmacogenomic Testing of Warfarin Therapy in Typical Community Practice Settings (MHSMayoWarf1)

November 15, 2010 updated by: Medco Health Solutions, Inc.

in Typical Community Practice Settings

The purpose of this quasi-experiment study, which could also be classified as a prospective observational intervention study, is to assess the impact of cytochrome P450 2C9 (CYP 2C9) and vitamin K epoxide reductase complex, subunit 1 (VKORC1) testing within a primary patient care setting.

Study Overview

Status

Completed

Conditions

Intervention / Treatment

Detailed Description

Anticoagulation therapy with warfarin is the most common mode of treatment and prophylaxis for venous and arterial thromboembolic conditions. Warfarin is metabolized in the liver by the cytochrome P450 system, the cytochrome P450 2C9 (CYP 2C9) isoenzyme specifically, and polymorphisms in the CYP 2C9 gene have been associated with changes in metabolic function of the translated isoenzyme . These polymorphisms result in reduced metabolism of warfarin as compared to subjects having the wild type gene, consequently leading to systemic accumulation of warfarin; it is theorized that this leads to higher risk of adverse events. Other allelic variations have also been linked to changes in vitamin K conservation through their effects on vitamin K epoxide reductase complex, subunit 1 (VKORC1) . The combined impact of CYP 2C9 and VKORC1 polymorphisms on warfarin's pharmacology have recently been reported.

It is hypothesized that evaluation of genomic allelic type guided warfarin dosing will reduce thromboembolic and bleeding risks associated with warfarin therapy, and that adoption of a genetic testing strategy in a primary patient care setting would improve warfarin effectiveness and patient safety, and reduce costs to health care payers.

Study Type

Observational

Enrollment (Actual)

1635

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
    • New Jersey
      • Franklin Lakes, New Jersey, United States, 07003
        • Medco Health Solutions, Inc.

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

40 years to 75 years (ADULT, OLDER_ADULT)

Accepts Healthy Volunteers

No

Genders Eligible for Study

All

Sampling Method

Non-Probability Sample

Study Population

The active study population consists of male and female covered lives with Medco for clients have agreed to enroll their members for ages 40-75 for new warfarin starts who match the inclusion criteria.

Description

Inclusion Criteria:

  • Female and male age range of 40-75
  • Patients who are in the induction phase of warfarin
  • Patients receiving warfarin to prevent or treat thromboembolic conditions (e.g., post orthopedic surgery prophylaxis, deep venous thrombosis, atrial fibrillation, pulmonary embolism, heart failure)
  • Patient willing to provide informed consent prior to the specimen collection procedure
  • Patient whose physician is willing to order the genetic test

Exclusion Criteria:

  • Age < 40 or > 75
  • Previous use of warfarin within 180 days of initiating new warfarin therapy
  • Hospitalized for seven or more days before first claim for warfarin
  • Previous history of genetic testing for warfarin therapy
  • Known hypersensitivity to warfarin
  • Patient or physician refusal to participate in the study
  • Patients using warfarin residing in Olmsted County, MN

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

Cohorts and Interventions

Group / Cohort
Intervention / Treatment
1
Historical control group. Patients in this group are drawn from the same plan populations as the intervention group, but they are identified during the 1-year period prior to the start of patient enrollment in the intervention group. The historical control group is closely matched with the intervention group on demographic characteristics, practice patterns, and benefit plan features that may affect resource utilization.
2
Concurrent control group. Patients in this group are drawn from different set of plan populations, but they initiate warfarin treatment during the same time period as patients in the intervention group. Outcomes data for the concurrent control group will be used to evaluate whether any differences between the intervention group and the historical control group can be attributed to changes in clinical practice over time. Baseline data for the concurrent control group will help validate the incidence assumptions used in the calculation of statistical power. This use of baseline population norms is an effective means of limiting bias in quasi-experimental studies.
3
Active study group. For plans participating in the active arm of the study, enrollment is offered to every patient who initiates warfarin therapy during the enrollment period (beginning in July 2007) and who meets the eligibility criteria. Patients are identified for the active study group if they have a warfarin pharmacy claim and no prior warfarin claims during the preceding 180 days. Only patients who remain eligible for the pharmacy benefit throughout the study period are included in the final sample.
Other: CYP 2C9 and VKORC1 Testing for Warfarin
Test patients for their warfarin sensitivity and provide this information to their physician authorizing the test.
Other Names:
  • Genetic testing for drug sensitivity

What is the study measuring?

Primary Outcome Measures

Outcome Measure
Time Frame
The primary objective of the study is to determine whether the addition of genotyping to usual care will reduce the hospitalization rates for hemorrhage or thromboembolism related to warfarin use during the first 6 months of treatment.
Time Frame: 6 months
6 months

Secondary Outcome Measures

Outcome Measure
Time Frame
The secondary objective is to determine physician and patient acceptance of the technology.
Time Frame: 6 months
6 months

Collaborators and Investigators

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

Sponsor

Medco Health Solutions, Inc.

Collaborators

Mayo Clinic
Washington University 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

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, 2007

Primary Completion (ACTUAL)

January 1, 2010

Study Completion (ACTUAL)

January 1, 2010

Study Registration Dates

First Submitted

January 26, 2009

First Submitted That Met QC Criteria

January 27, 2009

First Posted (ESTIMATE)

January 28, 2009

Study Record Updates

Last Update Posted (ESTIMATE)

November 16, 2010

Last Update Submitted That Met QC Criteria

November 15, 2010

Last Verified

November 1, 2010

More Information

Terms related to this study

Keywords

Additional Relevant MeSH Terms

Other Study ID Numbers

  • MedcoWarfarin1

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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