AstraZeneca enrols first patient in new Brilinta (ticagrelor) stroke trial

Latest Phase III trial to build on evidence of possible ticagrelor benefit in ischaemic stroke and will explore potential in prevention of cerebrovascular accidents  

23 January 2018

AstraZeneca today announced that the milestone of ‘first-subject-in’ (FSI) has been reached for Brilinta (ticagrelor), a P2Y12 inhibitor, currently indicated for the treatment of acute coronary syndromes and prevention of further coronary events in high-risk post-MI (myocardial infarction), in a new randomised, controlled Phase III trial investigating the potential of ticagrelor treatment in stroke. 

This new trial, named THALES, will evaluate the safety and efficacy of 30-day treatment with ticagrelor vs. placebo, on a background therapy of aspirin (ASA), for reducing recurrent stroke and death in patients who have already suffered an acute ischaemic stroke or high-risk transient ischaemic attack (TIA) in the previous 24 hours.

Dr Clay Johnston, Dean of the Dell Medical School at The University of Texas and lead investigator for THALES, said: “With so many potentially avoidable strokes occurring in high risk patients already on standard of care, this new trial for ticagrelor is extremely significant. Around the world, there are more than five million ischaemic strokes every year,1 the impact of which can be truly life-changing. I can think of few areas of medicine where the need for effective new treatments is greater, with the potential to transform outcomes for patients, their families and healthcare systems as a whole.”

THALES is part of PARTHENON, AstraZeneca’s largest-ever cardiovascular (CV) clinical outcomes programme involving patients at high risk of CV events. Through PARTHENON, ticagrelor has been tested in large-scale clinical trials that have included more than 100,000 people to date. Ticagrelor has also been studied through real-world evidence, which enhances our understanding of its potential long-term effects.2

THALES follows the read-out of the SOCRATES trial (ticagrelor monotherapy versus aspirin in acute stroke or transient ischaemic attack) in 2016 which, despite not meeting its primary endpoint of time from randomisation to the first occurrence of any event from the composite of stroke (ischaemic or haemorrhagic), MI, or death, suggested that ticagrelor may be effective in preventing recurrent ischaemic stroke after a stroke or TIA, when administered on a background therapy of low-dose ASA, and in the first weeks following a stroke or TIA when the risk is highest.3

Elisabeth Björk, Vice President, Head of Cardiovascular and Metabolic Diseases, Global Medicines Development, AstraZeneca, said: “THALES is a reinforcement of our long-term commitment to Brilinta, a medicine that has been prescribed to as many as five million people worldwide who are at high-risk post MI or have experienced an acute coronary syndrome.4 Stroke is the second highest cause of disability globally and the burden continues to rise.1,5 Our previous experience in these patients has enabled us to refine our hypothesis and, based on what we learned, better design a trial for Brilinta in stroke.”


About Brilinta (ticagrelor)

Brilinta is a direct-acting P2Y12 receptor antagonist in a chemical class called cyclo-pentyl-triazolo-pyrimidines (CPTPs). Brilinta works by inhibiting platelet activation and has been shown to reduce the rate of atherothrombotic CV events, such as heart attack or CV death, in patients with acute coronary syndromes (ACS).

Brilinta, co-administered with aspirin, also known as acetylsalicylic acid (ASA), is indicated for the prevention of atherothrombotic events in adult patients with ACS, or for patients with a history of myocardial infarction (MI) and a high risk of developing an atherothrombotic event.

About AstraZeneca in Cardiovascular, Renal & Metabolic Diseases (CVMD)

Cardiovascular, renal and metabolic diseases together form one of AstraZeneca’s main therapy areas and platforms for future growth. By following the science to understand more clearly the underlying links between the heart, kidney and pancreas, AstraZeneca is investing in a portfolio of medicines to protect organs and improve outcomes by slowing disease progression, reducing risks and tackling co-morbidities. Our ambition is to modify or halt the natural course of CVMDs and even regenerate organs and restore function, by continuing to deliver transformative science that improves treatment practices and CVMD health for millions of patients worldwide.

About AstraZeneca

AstraZeneca is a global, science-led biopharmaceutical company that focuses on the discovery, development and commercialisation of prescription medicines, primarily for the treatment of diseases in three therapy areas - Oncology, Cardiovascular & Metabolic Diseases and Respiratory. The Company also is selectively active in the areas of autoimmunity, neuroscience and infection. AstraZeneca operates in over 100 countries and its innovative medicines are used by millions of patients worldwide. 

For more information, please visit and follow us on Twitter @AstraZeneca.


1. Roth GA, Johnson C, Abajobir A, et al. Global, Regional, and National Burden of Cardiovascular Diseases for 10 Causes, 1990 to 2015. J Am Coll Cardiol. 2017;70:1-25.

2. Sahlén A, Varenhorst C, Lagerqvist B, et al. Outcomes in patients treated with ticagrelor or clopidogrel after acute myocardial infarction: experiences from SWEDEHEART registry. Eur Heart J. 2016;37:3335-3342.

3. AstraZeneca. Clinical Study Report. D5134C00001. June 2016.

4. IQVIA data on file. 2016

5. Feigin VL, Forouzanfar MH, Krishnamurthi R, et al. Global and regional burden of stroke during 1990-2010: findings from the Global Burden of Disease Study 2010. Global Burden of Diseases, Injuries, and Risk Factors Study 2010 (GBD 2010) and the GBD Stroke Experts Group. Lancet. 2014;383:245-54.