Ticagrelor Hits Mark in Large Stroke Study: THALES Top-line Results

The addition of ticagrelor (Brilinta; AstraZeneca) to aspirin significantly reduces the risk of death and stroke at 30 days compared with aspirin alone in patients who’ve had a minor acute ischemic stroke or transient attack (TIA) in the 24 hours prior to starting therapy, according to the top-line results of the THALES trial.

The study met its primary efficacy endpoint, said the sponsor, but patients treated with the direct-acting P2Y12 receptor antagonist and aspirin did experience more severe bleeding events than those treated with aspirin alone.

The THALES study, led by S. Claiborne “Clay” Johnston, MD, PhD (University of Texas at Austin), included more than 11,000 patients with minor acute ischemic stroke/TIA randomized to treatment within 24 hours of symptom onset and followed for 30 days. The active treatment arm included ticagrelor 180 mg on day 1 followed by ticagrelor 90-mg twice daily. All patients received 300-325 mg of aspirin on day 1 followed by aspirin 75-100 mg. The primary efficacy endpoint was the time to the composite endpoint of death and stroke at 30 days.

In a statement, Johnston said the increase in bleeding was expected, but also that ticagrelor reduced the risk of “potentially devastating events” in the critical 30-day window following a minor acute ischemic stroke or high-risk TIA.

The full study results are scheduled to be presented at an upcoming medical meeting, according to AstraZeneca. Ticagrelor is not approved in the setting of stroke but is approved for secondary prevention in patients with acute coronary syndrome or prior MI.