WASHINGTON (AP) — The Food and Drug Administration on Thursday approved a “super aspirin” to prevent blood clots. The new medicine, inspired by snake venom, could reduce the risk of heart attacks in people hospitalized with severe chest pain.
Merck & Co. estimated that if its drug Aggrastat were given to all Americans hospitalized annually with unstable angina, it could prevent up to 40,000 heart attacks and deaths.
“This is a huge step forward,” said Dr. Christopher Cannon, a cardiologist at Brigham & Women’s Hospital.
Unstable angina, a dangerous pain attack, is the leading reason for admitting people to coronary care units. Today, those patients are treated with aspirin and heparin, a blood thinner, to help stop the formation of blood clots that can trigger heart attacks. Still, 10 percent to 12 percent of patients go on to have a heart attack within a month of developing unstable angina.
Aggrastat is the first in a new class of medicines that, given in addition to heparin and aspirin, appears to cut that risk by about a third.
Ironically, Merck modeled the drug on snake venom.
Doctors knew that some snakebite victims bleed to death because the venom contains powerful anti-clotting proteins. Merck and researchers from Temple University isolated one of those proteins from an African snake called the Saw-scaled viper. Then Merck built the Aggrastat molecule to mimic the snake venom’s anticlotting effect, minus the toxins.
Having a new class of drug to treat these complex patients is important, said Dr. James Willerson, medical director of cardiology at the Texas Heart Institute. “It’s a different kind of inhibitor, and it certainly has appeared to be effective,” he said. “It will get wide use.”
“It doesn’t dissolve blood clots, but it will help prevent them from growing and causing heart attacks,” added Cannon, who has tested the drug.
The FDA, which classified Aggrastat as a priority drug, cautioned that the drug does increase a patient’s risk of bleeding. Particularly at risk are patients who go on to need an angioplasty, where a balloon is threaded into the artery to push aside blockage.
A similar clot preventer, Centocor’s ReoPro, already is used in certain angioplasty patients. But Aggrastat is the first novel platelet inhibitor available for the far larger number of unstable angina patients.
Aggrastat would be given intravenously over two to three days during hospitalization. Merck said it will begin shipping it to hospitals next week.