A government institute has stopped a portion of a stroke-prevention study because the combination of the drugs Plavix and aspirin were shown to be linked to increased rates of bleeding and death versus aspirin alone.
The study, which involved 3,000-patients, was funded by the National Institute of Neurological Disorders and Stroke (NINDS). The organization issued a clinical advisory last month about the early termination of the Plavix-aspirin arm of the study.
The study started in 2003 and was testing whether the blood thinner Plavix, co-marketed by Bristol-Myers Squibb Co. and Sanofi SA, together with aspirin could prevent recurring strokes in people who had recently suffered strokes in small vessels of the brain.
NINDS said it canceled the study after a data-safety monitoring board found in the summer that 6.5 percent of patients treated with the Plavix-aspirin combination experienced a bleeding event, versus 3.3 percent of those on aspirin alone. In addition, there were more deaths from all causes in the combination group than in the aspirin group, 5.8 percent versus 4.1 percent.
The analysis also showed that the Plavix-aspirin combination was unlikely to provide a significant benefit in stroke prevention had that part of the study continued to its conclusion.
NINDS stressed that the new study doesn’t affect the approved uses of the Plavix-aspirin combination to prevent future heart attacks, strokes and other cardiovascular events in people with acute coronary syndrome, a condition that includes chest pain associated with heart attacks or unstable angina.
Researchers plan to continue a portion of the study that is testing whether blood-pressure medications can prevent strokes and cognitive decline. The study, Secondary Prevention of Small Subcortical Strokes, is expected to be completed in April 2012.