From today, aspirin will be investigated in the world’s largest clinical trial of treatments for patients hospitalised with COVID-19. The Randomised Evaluation of COVid-19 thERapY (RECOVERY) trial is taking place in 176 hospital sites across the UK, and has so far recruited over 16,000 patients.
Patients with COVID-19 are at higher risk of blood clots forming in their blood vessels. Platelets, small cell fragments in the blood that stop bleeding, seem to be hyperreactive in COVID-19 and may be involved in the clotting complications. Since aspirin is an antiplatelet agent, it may reduce the risk of blood clots in patients with COVID-19.
Professor Peter Horby, from the Nuffield Department of Medicine, co-Chief Investigator of the RECOVERY trial, said ‘We felt it was particularly important to add aspirin to the trial since there is a clear rationale for believing that it might be beneficial and it is safe, inexpensive and widely available. We are looking for medicines for COVID-19 that can be used immediately by anyone, anywhere in the world. We do not know if aspirin is such a medicine but we will find out.’
It is anticipated that at least 2,000 patients will be randomly allocated to receive aspirin 150 mg daily plus usual standard-of-care, and results will be compared with at least 2,000 patients who receive standard-of-care on its own. Patients will not be allocated to receive aspirin if they have a known hypersensitivity to aspirin; if they have experienced recent major bleeding or if they already take aspirin or other antiplatelet agents. The main outcome RECOVERY will assess is mortality after 28 days. Other outcomes include the impact on hospital stay and the need for ventilation. It is likely to be several months before there is enough evidence to conclude whether aspirin has a significant benefit in COVID-19 patients.
Professor Martin Landray from the Nuffield Department of Population Health, who co-leads the RECOVERY trial, said ‘Aspirin is widely used to prevent blood clots in many other conditions, including heart attack, stroke, and pre-eclampsia in pregnant women. But enrolling patients in a randomised trial such as RECOVERY is the only way to assess whether there are clear benefits for patients with COVID-19 and whether those benefits outweigh any potential side effects such as the risk of bleeding.’
The decision to add aspirin to the trial was made by the University of Oxford researchers leading the trial in conjunction with the Chief Medical Officer, following a recommendation by the UK COVID-19 Therapeutics Advisory Panel.