Recruiting

Clopidogrel vs. Ticagrelor

Sponsor:

Sunnybrook Health Sciences Centre

Code:

NCT06714526

Conditions

Intracranial Atherosclerosis

Eligibility Criteria

Sex: All

Age: 40+

Healthy Volunteers: Not accepted

Interventions

Point-of-Care CYP2C19 Testing

ticagrelor + aspirin

clopidogrel + aspirin

Study Details

Brief summary:

Stroke is an important cause of death, disability, and memory problems in adults. The build-up of plaque in arteries inside the brain is known as "intracranial atherosclerotic disease" or "ICAD" for short, and can reduce blood flow in the brain. Clopidogrel is a medicine used to prevent strokes because it stops blood from clotting. However, there are some people who do not get as much benefit from Clopidogrel because of differences in their genes; they have a variation in a certain gene and their body is not able to properly process Clopidogrel. Another medication called Ticagrelor can benefit people who have this genetic variation. The study investigators will randomize patients who have had a stroke due to ICAD to receive genetic testing, or standard of care. The standard-of-care group will take Clopidogrel for 90 days. The genetic testing group will complete a genetic test to see if they can properly process Clopidogrel. Depending on the results of the genetic test, patients will either take Clopidogrel or Ticagrelor for 90 days. All patients will have a brain scan at baseline and 90 days to see if they had any new strokes. Patients will also complete tests and questionnaires about function and memory at baseline and 90 days. This study will be one of the first to see if it is feasible and safe to use genetic testing to help choose medications for patients who have had a stroke. This will help the study investigators design a larger study that can test if genetic testing in stroke patients reduces future stroke risk and improves health outcomes.

Conditions

Intracranial Atherosclerosis

Study ID

NCT06714526

Start date

Oct 7, 2025

Status verified date

Oct, 2025

Completion date

Aug, 2027

Anticipated

Primary completion date

Aug, 2027

Anticipated

Eligibility Criteria

Eligibility Criteria

Sex: All

Age: 40+

Healthy Volunteers: Not accepted

Inclusion Criteria:

  • Age ≥ 40 years old, male and female.
  • TIA or ischemic stroke secondary to symptomatic atherosclerotic stenosis of 30- 99% involving the intracranial ICA or MCA or posterior circulation arteries as evidenced by CT or MR angiography.
  • Index TIA or ischemic stroke event occurred within past 30 days.
  • Clinical indication for DAPT for at least 3 months.

Exclusion Criteria:

  • Any contraindication to DAPT.
  • Any contraindication to use of clopidogrel (Plavix) or ticagrelor (Brilinta), such as pregnancy. A pregnancy test will be performed on all women of child-bearing age prior to enrollment in the study.
  • Indication for chronic anticoagulation based on guideline recommendations or investigator's judgment (e.g., atrial fibrillation, mechanical heart valve, intracardiac clot, dilated cardiomyopathy, ejection fraction <30%, etc.).
  • Intracranial arterial occlusion (i.e. 100% stenosis) responsible for the acute brain ischemia.
  • Intracranial arterial stenosis secondary to causes other than atherosclerosis.
  • Extracranial carotid disease with a plan for carotid revascularization.
  • Intraluminal thrombus.
  • Unstable subdural hematoma within 12 months of randomization not amenable to embolization.
  • Previous spontaneous hemorrhagic stroke.
  • Traumatic brain hemorrhage within 1 month of randomization.
  • Living in a nursing home or requiring daily nursing care or assistance with activities of daily living.
  • Intracranial tumor (except meningioma) or any intracranial vascular malformation.
  • Life expectancy less than 6 months.
  • Enrolment in another study that would conflict with the current study.

Study Design

Enrollment

100 participants

Anticipated

Allocation

Randomized

Intervention Model

Parallel Assignment

Primary purpose

Treatment

Interventions and Outcome Measures

Arms

experimental: Point-of-Care CYP2C19 Testing

Patients will undergo point-of-care CYP2C19 testing with the Research Use Only (RUO) Genomadix Cube to inform the choice of P2Y12 inhibitor (i.e. clopidogrel vs ticagrelor).

no intervention: Standard of Care

Patients will receive standard-of-care ASA + clopidogrel.

Interventions

Point-of-Care CYP2C19 Testing

Genetic testing with the Genomadix cube to determine P2Y12 inhibitor

ticagrelor + aspirin

If patients are poor or intermediate metabolizers of clopidogrel, they will receive ticagrelor (90 mg PO BID) + aspirin (81 mg PO daily)

clopidogrel + aspirin

Normal, rapid, and ultra-rapid metabolizers of clopidogrel will receive 75 mg PO daily of clopidogrel and 81 mg PO daily of aspirin.

Primary outcome measure

  • Rate of recruitment [ Time Frame: Through study completion, an average of 90 days ]
  • Rate of study completion [ Time Frame: Through study completion, an average of 90 days ]
  • Rate of protocol deviations [ Time Frame: Through study completion, an average of 90 days ]
  • Proportion of patients with Symptomatic intracerebral hemorrhage (ICH) [ Time Frame: Through study completion, an average of 90 days ]
  • Proportion of patients with major extracranial bleeding [ Time Frame: Through study completion, an average of 90 days ]
  • Proportion of patients with non-bleeding adverse events [ Time Frame: Through study completion, an average of 90 days ]

Central Contacts and Locations

Central contacts

Mark I Boulos, MD

416-480-4473mark.boulos@sunnybrook.ca

Locations

Dr. Mark I. Boulos - Sunnybrook Health Sciences Centre

Recruiting

Toronto, Ontario, Canada, M4N3M5

Contacts

Mark I Boulos, MD, MSc

4164804473mark.boulos@utoronto.ca

More Information

Sponsor

Sunnybrook Health Sciences Centre

Last update posted

Nov 20, 2025

Last verified

Oct, 2025

Trial information was received from ClinicalTrials.gov and was last updated on 2026-09-10. This information was provided to ClinicalTrials.gov by Sunnybrook Health Sciences Centre on 2025-11-20.