Protocol for Improvement of Therapy With Warfarin (WARFALGORIT)

May 30, 2025 updated by: Maria Mariana Barros Melo Da Silveira, University of Pernambuco

Pharmacogenetic Algorithm for Warfarin Dose Predictor: Protocol for Improvement and Effectiveness of Therapy Anticoagulant

Atrial Fibrillation (AF) is the most common supraventricular arrhythmia in clinical practice. The presence of AF, as an independent factor, increases mortality by up to two times. One in every six cerebrovascular accidents (CVA) occurs in patients with AF, generating an annual risk of around 7% per year, which represents an increase of up to seven times in relation to the risk in the general population, leading to the need for start anticoagulant therapy. Warfarin is still the Oral Anticoagulant (OC) of choice, being the most used in several clinical situations. The variability of response to anticoagulants is related to pharmacokinetic and pharmacodynamic factors, adherence to treatment, age, diet, body mass index (BMI), liver function, body deposition of vitamin K, individual drug metabolism, drug interactions, comorbidities, in addition to of genetic factors. It is estimated that the annual risks associated with the use of OCs are between 2% and 8% for bleeding. The clinical benefit and risk of OAC therapy are associated with the time in which the values of therapeutic - TTR (time in therapeutic range). Measuring the quality of anticoagulation assesses whether therapy is being maintained within this range. Increased TTR is associated with a decrease in thromboembolic and/or hemorrhagic events. In the context of OCs, pharmacogenetics is the science that predicts the response to drugs, based on individual genetic markers. By understanding the relationship between the genotype and the response to a drug, pharmacogenomics has the potential to help healthcare professionals to predict the therapeutic dose of warfarin by genotyping patients for several Single Nucleotide Polymorphisms (SNPs) that affect metabolism or sensitivity to warfarin. Therefore, the main objectives of genotype-guided therapy are to improve the safety and efficacy of anticoagulant therapy. In Brazil, more specifically in the Brazilian Northeast, the use of a dose predictor algorithm is not common, which leads to high rates of complications and consequently increases the length of hospital stay. As a result, there is an increasing need to implement therapeutic technologies applied to precision health, explore studies on genetic polymorphisms and therapies guided by pharmacogenomics, aiming to understand the individual genetic effect on the metabolism of drugs such as warfarin.

Study Overview

Status

Status

Indicates the current recruitment status or the expanded access status.
Enrolling by invitation

Conditions

Conditions

The disease, disorder, syndrome, illness, or injury that is being studied. On ClinicalTrials.gov, conditions may also include other health-related issues, such as lifespan, quality of life, and health risks.

Intervention / Treatment

Intervention / Treatment

A process or action that is the focus of a clinical study. Interventions include drugs, medical devices, procedures, vaccines, and other products that are either investigational or already available. Interventions can also include noninvasive approaches, such as education or modifying diet and exercise.

Detailed Description

Atrial Fibrillation (AF) is the most common supraventricular arrhythmia in clinical practice. Patients with AF have a 5 times greater risk of causing stroke, especially ischemic stroke, than any other cardiovascular disease. This arrhythmia causes stasis and changes in the thrombosis-antithrombosis balance, which can form thrombi and embolize systemically, reaching the brain and causing stroke, leading to the need to start anticoagulant therapy. Warfarin is still the Oral Anticoagulant (OAC) of choice, being the most used in various clinical situations. With sensitivity to the drug varying in each person, treatment needs to be monitored regularly using the International Normalized Ratio (INR). The known genetic variants that have the greatest impact on the response to warfarin are the variants in the warfarin target, VKORC1, carriers of this variant require a lower dose of warfarin, and the enzyme encoded by CYP2C9, which is the most important when it comes to of involvement with the pharmacokinetics of warfarin. Polymorphisms in the CYP2C9 and VKORC1 genes are responsible for approximately 12 and 24%, respectively, of the variation in warfarin dose among. patients of European descent. Therefore, in the presence of one or more polymorphisms in one of these genes, it is necessary to adjust the warfarin doses. Previous studies have indicated that pharmacogenetic algorithms generally predict warfarin dose more accurately than other dosing methods. In Brazil, more specifically in the Brazilian Northeast, the use of a dose predictor algorithm is not common, which leads to high rates of complications and consequently increases the length of hospital stay. As an objective, the present study plans to implement a pharmacogenetic algorithm protocol for predicting warfarin dose, guided by genotype, versus a clinical protocol based only on drug dosage, in the population with atrial fibrillation, and to evaluate the superiority of the treatment.

Study Type

Study Type

Describes the nature of a clinical study. Study types include interventional studies (also called clinical trials), observational studies (including patient registries), and expanded access.
Interventional

Enrollment (Estimated)

Enrollment

The number of participants in a clinical study. The "anticipated" enrollment is the target number of participants that the researchers need for the study.
700

Phase

Phase

The stage of a clinical trial studying a drug or biological product, based on definitions developed by the U.S. Food and Drug Administration (FDA). The phase is based on the study's objective, the number of participants, and other characteristics. There are five phases: Early Phase 1 (formerly listed as Phase 0), Phase 1, Phase 2, Phase 3, and Phase 4. Not Applicable is used to describe trials without FDA-defined phases, including trials of devices or behavioral interventions.
  • Phase 3

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

  • Brazil
    • PE
      • Recife, PE, Brazil, 50100-010
        • University of Pernambuco

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

Eligibility Criteria

The key requirements that people who want to participate in a clinical study must meet or the characteristics they must have. Eligibility criteria consist of both inclusion criteria (which are required for a person to participate in the study) and exclusion criteria (which prevent a person from participating). Types of eligibility criteria include whether a study accepts healthy volunteers, has age or age group requirements, or is limited by sex.

Ages Eligible for Study

  • Adult
  • Older Adult

Accepts Healthy Volunteers

No

Description

Inclusion Criteria:

  • Be greater than or equal to 18 years old
  • Patients using warfarin or indicated to start therapy
  • Patients with AF in its various etiologies and in paroxysmal, persistent or permanent clinical presentations, with a diagnosis established through clinical examination confirmed by conventional electrocardiographic recording or by 24-hour ambulatory electrocardiographic recording (Holter)

Exclusion Criteria:

  • Patients who are not able to understand the explanations about the exams, as well as clarifications inherent to their participation in the research
  • Patients who stop following the instructions provided by researchers or whose questionnaires are incomplete;
  • Patients with liver disease or cancer of any etiology.

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

  • Primary Purpose: Treatment
  • Allocation: Randomized
  • Interventional Model: Parallel Assignment
  • Masking: Single

Arms and Interventions

Participant Group / Arm

Participant Group / Arm

A group or subgroup of participants in a clinical trial that receives a specific intervention/treatment, or no intervention, according to the trial's protocol.
Intervention / Treatment

Intervention / Treatment

A process or action that is the focus of a clinical study. Interventions include drugs, medical devices, procedures, vaccines, and other products that are either investigational or already available. Interventions can also include noninvasive approaches, such as education or modifying diet and exercise.
Experimental: Group 1 Experimental
Patients with AF using or indicating the need to start OAC therapy guided by a pharmacogene
Drug: pharmacogenetic algorithm
The dose predictor algorithm proposed in this work aims to maintain and quality treatment in an individualized and effective manner. In the routine use protocol, warfarin is prescribed based only on the INR collected within 5 days. The proposed intervention protocol is based on the patient's clinical and genetic factors, such as genetic polymorphisms, age, weight, height, race, use of amiodarone, statins, antifungals or antibiotics, tobacco use, clinical indication and what the RNI target.
Active Comparator: Group 2 Active Comparator
Patients with AF indicated for OAC therapy guided by institutional protocol.
Drug: Clinical treatment
Patients with AF indicated for OAC therapy guided by institutional protocol.

What is the study measuring?

Primary Outcome Measures

Primary Outcome Measures

In a clinical study's protocol, the planned outcome measure that is the most important for evaluating the effect of an intervention/treatment. Most clinical studies have one primary outcome measure, but some have more than one.
Outcome Measure
Measure Description
Time Frame
Incidence of Treatment-Emergent Adverse Events
Time Frame: 6 month
Assess the incidence of adverse events
6 month

Secondary Outcome Measures

Secondary Outcome Measures

In a clinical study's protocol, a planned outcome measure that is not as important as the primary outcome measure for evaluating the effect of an intervention but is still of interest. Most clinical studies have more than one secondary outcome measure.
Outcome Measure
Measure Description
Time Frame
incidence of adverse events (thromboembolic and hemorrhagic)
Time Frame: 6 month
clinical evaluation of the decrease of adverse events
6 month
Time in therapeutic range
Time Frame: 6 month
Assess the INR and its time within the therapeutic range
6 month

Collaborators and Investigators

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

Sponsor

Sponsor

The organization or person who initiates the study and who has authority and control over the study.
University of Pernambuco

Collaborators

Collaborators

An organization other than the sponsor that provides support for a clinical study. This support may include activities related to funding, design, implementation, data analysis, or reporting.
Universidade Federal de Pernambuco

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.

Helpful Links

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 (Actual)

Study Start

The actual date on which the first participant was enrolled in a clinical study. The "anticipated" study start date is the date that the researchers think will be the study start date.
October 21, 2024

Primary Completion (Estimated)

Primary Completion

The date on which the last participant in a clinical study was examined or received an intervention to collect final data for the primary outcome measure. Whether the clinical study ended according to the protocol or was terminated does not affect this date. For clinical studies with more than one primary outcome measure with different completion dates, this term refers to the date on which data collection is completed for all the primary outcome measures. The "anticipated" primary completion date is the date that the researchers think will be the primary completion date for the study.
July 1, 2026

Study Completion (Estimated)

Study Completion

The date on which the last participant in a clinical study was examined or received an intervention/treatment to collect final data for the primary outcome measures, secondary outcome measures, and adverse events (that is, the last participant's last visit). The "anticipated" study completion date is the date that the researchers think will be the study completion date.
July 1, 2027

Study Registration Dates

First Submitted

First Submitted

The date on which the study sponsor or investigator first submitted a study record to ClinicalTrials.gov. There is typically a delay of a few days between the first submitted date and the record's availability on ClinicalTrials.gov (the first posted date).
January 17, 2025

First Submitted That Met QC Criteria

First Submitted That Met QC Criteria

The date on which the study sponsor or investigator first submits a study record that is consistent with National Library of Medicine (NLM) quality control (QC) review criteria. The sponsor or investigator may need to revise and submit a study record one or more times before NLM's QC review criteria are met. It is the responsibility of the sponsor or investigator to ensure that the study record is consistent with the NLM QC review criteria.
January 17, 2025

First Posted (Actual)

First Posted

The date on which the study record was first available on ClinicalTrials.gov after National Library of Medicine (NLM) quality control (QC) review has concluded. There is typically a delay of a few days between the date the study sponsor or investigator submitted the study record and the first posted date.
January 23, 2025

Study Record Updates

Last Update Posted (Actual)

Last Update Posted

The most recent date on which changes to a study record were made available on ClinicalTrials.gov. There may be a delay between when the changes were submitted to ClinicalTrials.gov by the study's sponsor or investigator (the last update submitted date) and the last update posted date.
June 4, 2025

Last Update Submitted That Met QC Criteria

Last Update Submitted That Met QC Criteria

The most recent date on which the study sponsor or investigator submitted changes to a study record that are consistent with National Library of Medicine (NLM) quality control (QC) review criteria. It is the responsibility of the sponsor or investigator to ensure that the study record is consistent with the NLM QC review criteria.
May 30, 2025

Last Verified

Last Verified

The most recent date on which the study sponsor or investigator confirmed the information about a clinical study on ClinicalTrials.gov as accurate and current. If a study with a recruitment status of recruiting; not yet recruiting; or active, not recruiting has not been confirmed within the past 2 years, the study's recruitment status is shown as unknown.
May 1, 2025

More Information

Terms related to this study

Keywords

Additional Relevant MeSH Terms

Other Study ID Numbers

Other Study ID Numbers

Identifiers or ID numbers other than the NCT number that are assigned to a clinical study by the study's sponsor, funders, or others. These numbers may include unique identifiers from other trial registries and National Institutes of Health grant numbers.
  • 77321024.4.0000.5192
  • 444198/2023-7 (Other Grant/Funding Number: Conselho Nacional de Desenvolvimento Científico e Tecnológico)

Plan for Individual participant data (IPD)

Plan to Share Individual Participant Data (IPD)?

YES

IPD Plan Description

Respecting the general data protection law of the country of origin (Law No. 13,709/2018), obliterating the data that would identify the participants, we will grant, if necessary, the disclosure of genetic and clinical results, for research purposes.

IPD Sharing Time Frame

January 1, 2027 - January 1, 2032

IPD Sharing Supporting Information Type

  • STUDY_PROTOCOL
  • SAP
  • ICF
  • CSR

Drug and device information, study documents

Studies a U.S. FDA-regulated drug product

No

Studies a U.S. FDA-regulated device product

No

product manufactured in and exported from the U.S.

No

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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