CoagulationPhase 3LOCKNCT00794755

Low Dose Supplementation to Improve Anticoagulation Control With Oral Vitamin K as an Adjuvant to Warfarin Therapy

A Phase 3 study testing Vitamin K1 (Phytonadione) in people with Coagulation, run by Ottawa Hospital Research Institute at 1 site in Canada.

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

Who is it for?: Ages 18 years and older
Conditions the study is for: Coagulation
What is being tested?: Vitamin K1 (Phytonadione)
Type of treatment: Pill or oral medicine
Could I receive a placebo?: Yes, some participants may receive a placebo
How many people: 100 participants
Where: 1 siteCanada
Study dates: Nov 2008to Apr 2010
Phase: Phase 3
Are there results?: None posted in the registry

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 years and older
All sexes
No healthy volunteers
Adult, Older adult

Who may be able to join

>= 18 years old
Have been on warfarin anticoagulation for at least 9 months
Have an INR target range of 2.0-3.0
Have "unstable" anticoagulation control, defined as in the preceding 6 months having at least 3 INRs out of range (>= 3.2 or =<1.8) or at least 3 warfarin dose changes
Have anticoagulation managed by the Ottawa Hospital Thrombosis Clinic
Able to provide written, informed consent

Who cannot join

Anticipated interruption or termination of warfarin anticoagulation in the next six months for a period of 1 week or greater
Patient instability in the preceding six months suspected to be due to a) Interruption of warfarin therapy for a period of 1 week or more or b) Significant non-compliance (assessed from patient record)
Possess a known allergy to Vitamin K or lactose based placebos
Unable/Refusal to provide written, informed consent

Trial locations and contacts

1 site in 1 country.

Canada1 site

Ottawa Hospital Thrombosis Clinic
Ottawa, Ontario, K1Y4E9

Other trials in Canada

About this study

Official title: A Phase III Pilot RCT (Randomized, Controlled Trial) to Assess the Effectiveness of Low Dose Vitamin K1 (200 Micrograms Per Day) on Improving Anticoagulation Control in Unstable Patients on Warfarin

The main objective of this study is to assess the effectiveness of low dose Vitamin K1 (200 micrograms per day) at improving anticoagulation control in unstable patients on warfarin. This study will also aim to look at effectiveness in the context of genes known to influence warfarin metabolism, variability in the consumption of Vitamin K rich foods, and patient knowledge about warfarin anticoagulation -- factors which have been associated with anticoagulation control and which can influence the effectiveness of this intervention in clinical practice.

Read the detailed description

A double-blinded placebo controlled pilot RCT assessing the effectiveness of daily supplementation with low dose Vitamin K1 (200 micrograms per day) against placebo at improving anticoagulation control. Previous studies assessing the efficacy of this intervention have been small and further trials are required to evaluate the true effectiveness and safety profile. Furthermore the impact of genetic polymorphisms, known to impact warfarin metabolism, on the effectiveness/safety of this intervention will also be assessed in this study. Demographic and clinical variables as well as potential confounding variables such as variable dietary Vitamin K intake, concomitant interacting medications, and anticoagulation knowledge will be assessed in this study. Given that this is a pilot study we will be looking at recruitment numbers and necessary parameter estimates to determine the number of patients available at our institution for the study. Power analysis will be performed to evaluate the treatment effect size between the placebo and intervention groups.

Conditions: Coagulation
Being tested: Vitamin K1 (Phytonadione), Placebo
Keywords: Vitamin K, Vitamin K1 (Phytonadione), Unstable INR, VTE or Thrombosis, Warfarin, Anticoagulation Control, Patients on warfarin with unstable anticoagulation control
Medical subject headings: Thrombosis

What participants receive

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

Vitamin K1 (Phytonadione)Dietary supplement
Vitamin K1 tablets (100 micrograms per tablet) will be taken by patients randomized to the Vitamin K arm. Dosage is two tablets per day (200 micrograms per day) to be taken with warfarin for the 6 month study period.
PlaceboDietary supplement
Lactose-based placebo tablets (identical in appearance to the Vitamin K1 tablets) will be taken by patients randomized to the placebo arm. Dosage is two tablets per day to be taken with warfarin for the 6 month study period.

Study groups in NCT00794755
Study group	Role	What they receive
Vitamin K	Active comparator	Not described Receives: Dietary Supplement: Vitamin K1 (Phytonadione)
Placebo	Placebo comparator	Not described Receives: Dietary Supplement: Placebo

What is being measured

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

Anticoagulation control -- Point estimates (and standard deviations) for the following variables: Percent time in therapeutic range, standard deviation of INRs, number of INRs outside of therapeutic range, and number of dose changes
Measured: At study initiation (for the six month pre-intervention period) and at study completion (after the six-month intervention period)
Recruitment Numbers -- Number of patients deemed eligible, Number of patients solicited, Number of patients screened, Number of patients enrolled, and Number of enrolled patients lost to follow-up
Measured: Monthly

Secondary outcomes (2)

Bleeding Events -- Both major and minor as defined by the International Society on Thrombosis and Haemostasis (ISTH) criteria
Measured: Over 6 month study period
Recurrent thrombosis
Measured: Over six month study period

Timeline

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

Nov 2008Apr 2010

First posted20 Nov 2008 (estimated)
Study startNov 2008
Primary completionApr 2010
Study completionApr 2010

Resources

Official record on ClinicalTrials.govThe registry entry this page is built from, with its full change history.
Other trials for CoagulationStudies of the same condition, open and under way.
More trials run by Ottawa Hospital Research InstituteThe sponsor's other registered studies.
What the trial phases meanHow a treatment moves from first tests in people to approval.

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 3
Primary purpose: Treatment
Allocation: Randomised
Intervention model: Parallel groups
Masking: Triple blind
Who is masked: Participant, Investigator, Outcomes assessor
Enrolment: 100 participants (estimated)

IDs, dates and publications

ClinicalTrials.gov ID: NCT00794755
Sponsor's protocol ID: OHREB #2008555-01H
Acronym: LOCK
Status last verified: Jul 2011
First submitted: 18 Nov 2008
Last updated: 27 Jul 2011
Results posted: No
Data monitoring committee: Yes

Want to know more?

The sponsor has not listed a contact. The official record may have more details.

Talk to your doctor first and take this page with you. Only the study team can confirm whether you can join.

Questions to ask the study team

What is the study trying to find out?
What would I need to do, and how often would I visit?
Could I receive a placebo instead of the treatment?
What are the possible risks and benefits for me?
Will it cost me anything? Are travel or time paid for?
Can I keep seeing my own doctor during the study?
What happens when the study ends?

See locations

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All Coagulation trials

Study at a glance

From the registry record, last updated by the sponsor on 27 Jul 2011. Recruitment status is as the sponsor reported it: confirm with the study team.

Official title: A Phase III Pilot RCT (Randomized, Controlled Trial) to Assess the Effectiveness of Low Dose Vitamin K1 (200 Micrograms Per Day) on Improving Anticoagulation Control in Unstable Patients on Warfarin
ClinicalTrials.gov ID: NCT00794755
Acronym / sponsor ID: LOCK / OHREB #2008555-01H
Conditions: Coagulation
Keywords: Vitamin K, Vitamin K1 (Phytonadione), Unstable INR, VTE or Thrombosis, Warfarin, Anticoagulation Control, Patients on warfarin with unstable anticoagulation control
Phase: Phase 3
Study type: Interventional
Recruitment status: Completed
Enrolment: 100 participants (estimated)
Lead sponsor: Ottawa Hospital Research InstituteUniversity, hospital or other
Study start: Nov 2008
Primary completion: Apr 2010 (actual)
Study completion: Apr 2010 (actual)
First posted: 20 Nov 2008 (estimated)
Results: Not posted in the source record

Clinical summary

The research question as the sponsor registered it. This describes what the study plans to test, not what it found.

Detailed description

Study design

Primary purpose: Treatment
Allocation: Randomised
Intervention model: Parallel groups
Masking: Triple blind (participant, investigator, outcomes assessor)
Number of arms: 2

Arm	Type	Receives
Vitamin K	Active comparator	Dietary Supplement: Vitamin K1 (Phytonadione)
Placebo	Placebo comparator	Dietary Supplement: Placebo

Who may qualify

Ages: 18 years and older
Sex: All
Healthy volunteers: Not accepted
Age groups: Adult, Older adult

Key inclusion criteria (6 listed)

>= 18 years old
Have been on warfarin anticoagulation for at least 9 months
Have an INR target range of 2.0-3.0
Have "unstable" anticoagulation control, defined as in the preceding 6 months having at least 3 INRs out of range (>= 3.2 or =<1.8) or at least 3 warfarin dose changes
Have anticoagulation managed by the Ottawa Hospital Thrombosis Clinic

Key exclusion criteria (4 listed)

Anticipated interruption or termination of warfarin anticoagulation in the next six months for a period of 1 week or greater
Patient instability in the preceding six months suspected to be due to a) Interruption of warfarin therapy for a period of 1 week or more or b) Significant non-compliance (assessed from patient record)
Possess a known allergy to Vitamin K or lactose based placebos
Unable/Refusal to provide written, informed consent

Eligibility is decided by the study team after screening; this overview does not establish that a patient qualifies. Full inclusion and exclusion criteria.

Interventions

Intervention	Type	Arms
Vitamin K1 (Phytonadione)Vitamin K1 tablets (100 micrograms per tablet) will be taken by patients randomized to the Vitamin K arm. Dosage is two tablets per day (200 micrograms per day) to be taken with warfarin for the 6 month study period.	Dietary supplement	Vitamin K
PlaceboLactose-based placebo tablets (identical in appearance to the Vitamin K1 tablets) will be taken by patients randomized to the placebo arm. Dosage is two tablets per day to be taken with warfarin for the 6 month study period.	Dietary supplement	Placebo

Primary outcome

Anticoagulation control -- Point estimates (and standard deviations) for the following variables: Percent time in therapeutic range, standard deviation of INRs, number of INRs outside of therapeutic range, and number of dose changes
Time frame: At study initiation (for the six month pre-intervention period) and at study completion (after the six-month intervention period)
Recruitment Numbers -- Number of patients deemed eligible, Number of patients solicited, Number of patients screened, Number of patients enrolled, and Number of enrolled patients lost to follow-up
Time frame: Monthly

2 secondary outcomes

Bleeding Events -- Both major and minor as defined by the International Society on Thrombosis and Haemostasis (ISTH) criteria
Time frame: Over 6 month study period
Recurrent thrombosis
Time frame: Over six month study period

Results and safety

The study is completed, but results are not available in the source record. That does not mean the treatment did or did not work.

Research links

Official record on ClinicalTrials.govLast updated by the sponsor 27 Jul 2011.

Related trials for Coagulation

RecruitingObservational study
A Study in Children and, Adults With Congenital Thrombotic Thrombocytopenic Purpura (cTTP) Treated With Adzynma
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RecruitingObservational study
The CACHE Study: Coronary Artery Care in HaEmophilia
Haemophilia, Cardiovascular Diseases
Active, not recruitingObservational study
An Observational Study of Participants With Type 3 Von Willebrand Disease on Prophylactic Standard-of-Care Treatment
Von Willebrand Disease, Type 3
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A Study to Assess the Tolerability of Ianalumab (VAY736) With Investigator's Choice Thrombopoietin Receptor Agonist (IC TPO-RA) in Patients With Primary Immune Thrombocytopenia (ITP)
Primary Immune Thrombocytopenia (ITP), Primary Evans Syndrome (ES)
Active, not recruitingObservational study
A Study to Learn About the Study Medicine -Hympavzi in Congenital Hemophilia Patients Without Inhibitors in Japan.
Hemophilia A or B

Referral and contact

AzTrials does not enrol participants or take referrals. Contact the study team or a site listed below; they decide who can take part. This study is not recruiting at the moment.

Philip S Wells, MD, MSc principal investigator

Ottawa Hospital, Ottawa Health Research Institute

1 site in 1 country: see every site and its status.

Questions about this trial

What is this clinical trial studying?

A Phase 3 study testing Vitamin K1 (Phytonadione) in people with Coagulation, run by Ottawa Hospital Research Institute at 1 site in Canada.

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 6 inclusion and 4 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 27 Jul 2011. 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 Canada. 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. Some participants in this study may receive a placebo. The study team explains the known risks during informed consent, before anyone joins; the record itself does not list them.

What does this phase mean?

Phase 3 studies compare the treatment with the current standard treatment or a placebo in a large group, to confirm how well it works and watch for side effects.

Not every study follows the same path, and some studies (observational studies, device studies) have no phase.

Are results available for this study?

The study is completed, but results are not available in the source record. That does not mean the treatment did or did not work.

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?

Anticoagulation control -- Point estimates (and standard deviations) for the following variables: Percent time in therapeutic range, standard deviation of INRs, number of INRs outside of therapeutic range, and number of dose changes (time frame: At study initiation (for the six month pre-intervention period) and at study completion (after the six-month intervention period)). 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 NCT00794755.

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 27 Jul 2011.