KEY THALES SECONDARY EFFICACY END POINT
In patients with acute ischemic stroke (NIHSS ≤5) or high-risk TIA, BRILINTA provided superior risk reduction of subsequent ischemic stroke vs aspirin alone1
THALES secondary efficacy end point: Subsequent ischemic stroke at 30 days
Do you have questions about the THALES study?
IPSILATERAL ATHEROSCLEROTIC STENOSIS SUBGROUP
In patients with acute ischemic stroke (NIHSS ≤5) or high-risk TIA, BRILINTA + aspirin vs aspirin alone4
- 21.3% of patients in the overall THALES trial (2351/11,016) had ipsilateral stenosis (≥30%) of the cervicocranial vasculature*
THALES PRESPECIFIED EXPLORATORY SUBGROUP: Primary composite end point of stroke or death in patients with ipsilateral atherosclerotic stenosis ≥30% at 30 days
- In patients without ipsilateral stenosis: Composite of stroke or all-cause death at 30 days: 4.8% vs 5.3% with BRILINTA plus aspirin (N=4387) and aspirin alone (N=4278), respectively (HR 0.89; 95% CI 0.74–1.08; NNT for patients without ipsilateral atherosclerosis is 200†)
- BRILINTA is not indicated to reduce death in patients with acute ischemic stroke or high-risk TIA
*Included patients with symptomatic intracranial or extracranial arterial stenosis, that is, ≥30% narrowing in the diameter of the lumen of an artery that could account for the clinical presentation (irrespective of >4 mm thick aortic arch plaque). Thirty percent narrowing was chosen as cutoff based on criteria of the atherosclerosis, small vessel disease, cardiac pathology, other disease, dissection (ASCOD) grading system.
†NNT was calculated using 1/ARR of BRILINTA + aspirin compared to aspirin alone (0.5%).4
THALES was not designed or powered to demonstrate the efficacy or safety of BRILINTA compared with placebo in specific subgroups. Subgroup analyses were performed to evaluate consistency of results in different cohorts. Analyses must be interpreted cautiously, as differences can reflect the play of chance among a large number of analyses.
Do you have questions about the THALES study?
SUBSEQUENT DISABLING STROKE PRESPECIFIED ANALYSIS5
In patients with acute ischemic stroke (NIHSS ≤5) or high-risk TIA
THALES prespecified exploratory analysis: Disability associated with a subsequent stroke by varying mRS threshold5*
*mRS=modified Rankin Scale. Scores range from 0 to 6 (0-1=no disability; 2-5=increasing disability; 6=death).
THALES was not designed or powered to demonstrate the efficacy or safety of BRILINTA compared with placebo in exploratory analyses. Exploratory analyses were performed to evaluate consistency of results in different cohorts. Analyses must be interpreted cautiously, as differences can reflect the play of chance among a large number of analyses.1
Do you have questions about the THALES study?
SUBSEQUENT DISABLING STROKE PRESPECIFIED ANALYSIS5
In patients with acute ischemic stroke (NIHSS ≤5) or high-risk TIA, Total disability burden at 30 days in patients with a subsequent ischemic stroke
THALES prespecified exploratory analysis: mRS distribution at 30 days in patients with a subsequent ischemic stroke5*
*mRS=modified Rankin Scale. Scores range from 0 to 6 (0-1=no disability; 2-5=increasing disability; 6=death).
THALES was not designed or powered to demonstrate the efficacy or safety of BRILINTA compared with placebo in exploratory analyses. Exploratory analyses were performed to evaluate consistency of results in different cohorts. Analyses must be interpreted cautiously, as differences can reflect the play of chance among a large number of analyses.1
Do you have questions about the THALES study?
THALES STUDY DESIGN
THALES was a randomized, international, double-blind, placebo-controlled, multicenter study to investigate dual antiplatelet therapy with BRILINTA (180-mg loading dose, 90 mg twice daily thereafter) and aspirin vs placebo and aspirin in the prevention of stroke or death in patients with acute ischemic stroke or transient ischemic attack (N=11,016). The primary end point was the first occurrence of the composite of stroke or death at 30 days. In both arms, patients received a loading dose of aspirin 300-325 mg followed by aspirin 75-100 mg once daily. Patients were ≥40 years of age, had mild-to-moderate acute noncardioembolic ischemic stroke (NIHSS score ≤5), or high-risk TIA (ABCD2 score ≥6 or symptomatic intracranial or extracranial arterial stenosis [≥50% narrowing in the diameter of the lumen of an artery that could account for the TIA]). Patients were randomized within 24 hours and treated for a median of 31 days.1,2
ABCD2=Age, Blood pressure, Clinical features, Duration of TIA, and Diabetes mellitus; ARR=absolute risk reduction; CI=confidence interval; HR=hazard ratio; K-M=Kaplan-Meier; mRS=modified Rankin Scale; NIHSS=National Institutes of Health Stroke Scale; NNT=number needed to treat; RRR=relative risk reduction; THALES=Acute STroke or Transient IscHemic Attack Treated with TicAgreLor and Aspirin for PrEvention of Stroke and Death; TIA=transient ischemic attack.
References
- Johnston SC, Amarenco P, Denison H, et al; THALES Investigators. Ticagrelor and aspirin or aspirin alone in acute ischemic stroke or TIA. N Engl J Med. 2020;383(3):207-217 and Supplementary Appendix.
- BRILINTA® (ticagrelor) [package insert]. Wilmington, DE: AstraZeneca Pharmaceuticals LP; 2024.
- Data on File, REF-51076, AstraZeneca Pharmaceuticals LP.
- Amarenco P, Denison H, Evans SR, et al. Ticagrelor added to aspirin in acute nonsevere ischemic stroke or transient ischemic attack of atherosclerotic origin. Stroke. 2020;51(12):3504-3513.
- Amarenco P, Denison H, Evans SR, et al; THALES Steering Committee and Investigators. Ticagrelor added to aspirin in acute ischemic stroke or transient ischemic attack in prevention of disabling stroke: a randomized clinical trial. JAMA Neurol. 2020;78(2):1-9.
THE THALES STUDY1
11,016 patients were randomized within 24 hours and treated for 30 days1
OBJECTIVE
THALES compared dual antiplatelet therapy (DAPT) with BRILINTA 90 mg and aspirin vs placebo and aspirin in patients with acute ischemic stroke or high-risk TIA for the primary efficacy end point of the composite of stroke or death and the primary safety end point of first GUSTO severe bleeding.
STUDY DESIGN
Randomized, double-blind, placebo-controlled, parallel-group, multicenter trial conducted across 28 countries and 414 sites

Primary efficacy composite end point: Stroke (ischemic and hemorrhagic) or all-cause death
Key secondary efficacy end point: Ischemic stroke
Primary safety end point: GUSTO severe bleeding
Key inclusion criteria
- Patients ≥40 years of age, randomized within 24 hours after onset of symptoms, with:
- Mild-to-moderate acute noncardioembolic ischemic stroke (NIHSS score ≤5 and persistent signs or symptoms at the time of randomization or acute ischemic brain lesion determined by CT scan or MRI)
OR
- High-risk TIA (ABCD2 score ≥6 or with large-vessel disease [ie, ipsilateral ≥50% stenosis of extra- or intracranial artery])
Key exclusion criteria
- Thrombolysis or mechanical thrombectomy within 24 hours before randomization
- Planned use of anticoagulation
- Planned use of antiplatelet therapy other than aspirin
- History of atrial fibrillation/flutter or ventricular aneurysm
- Suspicion of a cardioembolic cause of TIA or stroke
- History of ICH or GI bleeding within the past 6 months or major surgery within 30 days
*Loading doses were given to patients as soon as possible after randomization on day 1.
ABCD2=Age, Blood pressure, Clinical features, Duration of TIA, and Diabetes mellitus; BID=twice daily; CT=computed tomography; GI=gastrointestinal; GUSTO=Global Use of Strategies to Open Occluded Coronary Arteries; ICH=intracranial hemorrhage; LD=loading dose; MRI=magnetic resonance imaging; NIHSS=National Institutes of Health Stroke Scale; QD=once daily; THALES=Acute STroke or Transient IscHemic Attack Treated with TicAgreLor and Aspirin for PrEvention of Stroke and Death; TIA=transient ischemic attack.
Reference: 1. Johnston SC, Amarenco P, Denison H, et al; THALES Investigators. Ticagrelor and aspirin or aspirin alone in acute ischemic stroke or TIA. N Engl J Med. 2020;383(3):207-217, Supplementary Appendix, and Protocol.