The SOCRATES clinical trial has concluded with summary results having been released to the public. More detailed results will be presented at the European Stroke Organisation Conference in Barcelona, Spain next week.
The trial randomized patients with transient ischemic attacks (TIA) considered to be high risk for stroke and patients with “mild” strokes to take either ticagrelor (Brilinta), a medication that impairs platelet function currently in use the prevention of heart attacks in patients with coronary artery disease or with coronary stents in place, or aspirin. Ticagrelor was taken at a dose of 90mg twice daily, and aspirin was taken at a dose of 100mg daily (plus placebo for the second dose – patients were blinded to which drug they were taking). Patients had to enter the trial within 24 hours of their TIA or stroke symptoms beginning. The endpoints were the amount of time until a recurrent stroke, a heart attack, or death. While the patients in the ticagrelor group are being reported as having fared slightly better than those in the aspirin group, the results were not statistically significant. This means that there is no significant benefit in the primary prevention of stroke after a TIA or in the secondary prevention of stroke following a mild stroke that ticagrelor carries over aspirin.
What does this mean? If you refer to the image to the left, you will see a big part of what it means
– about $300-plus per month in savings for some patients if they now opt for aspirin over a patented drug for which there is no generic equivalent.
It also raises the question about whether pharmaceutical companies will fund clinical trials that cost millions of dollars to run and carry to completion in order to obtain an additional indication for a drug’s use. It’s a gamble. If companies don’t fund trials to demonstrate efficacy, then insurers are less likely to cover drugs for patients, and patients are more likely to opt for a less expensive option, if available. If they fund trials and the drug being tested is not effective, or is not superior to a less expensive option that already widely exists, then not only is it millions down the drain, but negative press about the company and the drug. However, if the drug is shown to be more effective than the cheaper, more widely available option, then the return on investment could be huge.
Personally, I was shocked. Ticagrelor carries a reputation of being a potent antiplatelet medication, and many of us who treat patients with stroke or heart disease felt that this was a softball sort of trial. Of course the ticagrelor was going to win solidly – because it was being compared only to a substance that has been available over-the-counter for decades, a drug that went generic in the 1930s and whose history dates back over 2,000 years as a substance produced by the willow tree. Could it really be that something as simple and low cost as aspirin could rival an expensive, patented, relatively new prescription drug? According to SOCRATES, this may well be the case.
There were limitations to SOCRATES. It’s always difficult to incorporate every possible scenario into a clinical trial, especially in a disease like stroke where each one is different. This did not test whether the combination of aspirin and ticagrelor was more effective than aspirin alone. It also did not compare ticagrelor to other antiplatelet drugs that are generic, such as clopidogrel (Plavix). Medicine is still an art, because above all, it’s important to treat each individual patient with the information available while applying good judgment.