Genotype-Based Warfarin Therapy (GENWAT) study

Genotype-Based Warfarin Therapy (GENWAT) study - Genotype-Based Warfarin Therapy (GENWAT) study

Status

Active, not recruiting

Phases

Unknown

Study type

Interventional

Source

JPRN

Registry ID

JPRN-UMIN000006794

Enrollment

1000

Registered

2011-12-01

Start date

2011-12-01

Completion date

Unknown

Last updated

2026-06-29

For informational purposes only — not medical advice. Sourced from public registries and may not reflect the latest updates. Terms

Conditions

Atrial fibrillation

Interventions

PG Arm: Decision of initial dosage using warfarin dosing algorism by genotype and clinical information (to a maximum of 5 mg). STD Arm: Initiation of warfarin treatment at a dose of 1 to 2 mg.

Eligibility

Sex/Gender

All

Inclusion criteria

Inclusion criteria: 1) Adult Japanese males and females with atrial fibrillation, who will take warfarin 2) Patients who can understand the contents of this study and will voluntarily give written informed consent

Exclusion criteria

Exclusion criteria: 1) Patients with a history of hypersensitivity to warfarin 2) Pregnancy and lactation patients 3) Patients with severe renal failure (serum creatinine>=2.5 mg/dL, patients on hemodialysis) 4) Patients with cirrhosis 5) Patients with hypoproteinemia (serum albumin<=2.5 g/dL) 6) Patients who require special attention for dosage adjustment 7) Patients with bleeding and who are potentially bleeding 8) Patient who are incapable to understand the contents of this study and will not give informed consent 9) Patients who participate in other clinical studies 10) Patients judged by investigators as ineligible for study enrollment 11) Patients who require invasive treatment during this study

Design outcomes

Primary

Measure	Time frame
1) Efficacy i) Proportion of patients reaching therapeutic INR range (1.6 to 2.5) at week 2, 4 and 8 ii) Time to the therapeutic INR range 2) Safety i) Bleeding (hematoma, hemorrhage in CNS, GI, GU, pulmonary/upper respiratory, petechiae/purpura, other hemorrhage) ii) Thromboembolism (cerebral embolism, cardiac thrombosis, pulmonary embolism, deep vein thrombosis) iii) INR>=4 iv) Discontinuation of warfarin due to inhibition of coagulation v) Use of Vitamin K medication	—

Measure

Time frame

1) Efficacy i) Proportion of patients reaching therapeutic INR range (1.6 to 2.5) at week 2, 4 and 8 ii) Time to the therapeutic INR range 2) Safety i) Bleeding (hematoma, hemorrhage in CNS, GI, GU, pulmonary/upper respiratory, petechiae/purpura, other hemorrhage) ii) Thromboembolism (cerebral embolism, cardiac thrombosis, pulmonary embolism, deep vein thrombosis) iii) INR>=4 iv) Discontinuation of warfarin due to inhibition of coagulation v) Use of Vitamin K medication

—

Secondary

Measure	Time frame
1) Efficacy i) Total number of dose adjustments for reaching therapeutic INR range ii) Total number of INR measurements for reaching therapeutic INR range iii) Differences between initial and maintenance dosages	—

Countries

Japan

Outcome results

None listed

Source: JPRN (via WHO ICTRP) · Data processed: Jul 3, 2026