Study of Genetic Factors Other Than CYP2C9 and VKORC1 That Influence Warfarin Dose Requirements in a South-east Asian Population

Cancer Clinical Trial

Clinical Trial Details — Status: Recruiting

Administrative data

• NCT number: NCT01050920
• Other study ID #: PK03/32/09
• Status: Recruiting
• Phase: N/A
• First received: January 15, 2010
• Last updated: January 21, 2014
• Start date: September 2013
• Est. completion date: December 2014

Study information

• Verified date: January 2014
• Source: National University Hospital, Singapore
• Contact: Soo Chin Lee, MBBS, MRCP
• Phone: 65 6772 4629
• Email: soo_chin_lee[@]nuhs.edu.sg
• Is FDA regulated: No
• Health authority: Singapore: Domain Specific Review Boards
• Study type: Observational

Clinical Trial Summary

Warfarin is a commonly used anti-coagulant, but has a narrow therapeutic index and wide inter-individual and inter-ethnic variation in dose requirements. Several genetic and non-genetic factors have been identified that could influence warfarin dose requirements. However, current known predictive factors could only explain about 50-60% of warfarin dose variability. Inter-ethnic differences in genetic influences on warfarin dose requirements also exist. We hypothesize that genetic factors other than CYP2C9 and VKORC1 may influence warfarin dosing and serve to further optimize warfarin dosing.

Recruitment information / eligibility

• Status: Recruiting
• Enrollment: 0
• Est. completion date: December 2014
• Est. primary completion date: December 2014
• Accepts healthy volunteers: No
• Gender: Both
• Age group: 21 Years and older

Eligibility

Inclusion Criteria:

• patients receiving maintenance warfarin therapy with a stable therapeutic international normalized ratio (INR) between 2 and 3 for at least 3 months,

• patients recruited from the anticoagulation clinics at the National University Hospital and Tan Tock Seng Hospital in Singapore between June 2002 and June 2004 for a previous genotyping study (C/00/510, NUH; C/00/535, TTSH, PI-Dr Goh Boon Cher).

Exclusion Criteria:

• patients below 21 years old, or

• patients with liver disease, malabsorption or chronic diarrheal diseases, or

• patients taking drugs that may potentially interact with warfarin.

Dietary advice to avoid foods that may interfere with warfarin pharmacokinetics will be given to patients during warfarin therapy.

Study Design

Observational Model: Cohort, Time Perspective: Cross-Sectional

Related Conditions & MeSH terms

• Cancer

Intervention

Biological:
• Blood collection

Locations

Country	Name	City	State
Singapore	National University Hospital	Singapore

Sponsors (1)

Lead Sponsor	Collaborator
National University Hospital, Singapore

Country where clinical trial is conducted

Singapore, 

References & Publications (2)

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. — View Citation

Poller L, Taberner DA. Dosage and control of oral anticoagulants: an international collaborative survey. Br J Haematol. 1982 Jul;51(3):479-85. — View Citation

Outcome

Type	Measure	Description	Time frame	Safety issue
Primary	To identify genetic variants other than CYP2C9 and VKORC1 that may influence warfarin dose requirements in a multi-ethnic population in Singapore.