FDA Approves a New Kind of Blood Thinner to Help Prevent Repeat Strokes

Americans who survive a stroke live with a hard truth: the risk of another one is high. On Nov. 9, the Food and Drug Administration approved a new kind of medicine designed to lower that risk, the agency announced.

The drug, Bayer's Sunharbo, known generically as asundexian, is a 50-milligram tablet taken once a day, according to the FDA. It is the first approved drug in a class called factor XIa inhibitors.

The FDA approved Sunharbo for adults who have recently had a mild-to-moderate ischemic stroke that did not come from a clot in the heart, or a high-risk transient ischemic attack, often called a mini-stroke, to be taken along with antiplatelet therapy such as aspirin. It is not approved for patients with atrial fibrillation, the irregular heart rhythm that is a major source of stroke-causing clots. BioPharma Dive reported that the drug stumbled in an earlier key study in atrial fibrillation.

The most widely used clot-preventing drugs today, such as Eliquis and Xarelto, block a protein in the clotting system called factor Xa, Reuters reported. Sunharbo targets a different protein, factor XIa. BioPharma Dive explained that factor XIa plays only a minor role in sealing injured blood vessels but helps harmful clots grow, so blocking it is meant to prevent dangerous clots while preserving the body's ability to stop bleeding.

The approval rests on a large study called OCEANIC-STROKE, which enrolled 12,327 adults who started treatment within 72 hours of their symptoms, the FDA said. Patients were treated for a median of about 14 months.

Ischemic strokes occurred in 6.2% of patients taking asundexian, compared with 8.4% of those taking a placebo, a 26% relative reduction, NeurologyLive reported. In plain terms, about two fewer patients out of every 100 had another stroke. The combined rate of cardiovascular death, heart attack or stroke was 9.2% versus 11.1%.

Just as important for a blood thinner, major bleeding occurred in 1.9% of patients on the drug and 1.7% on placebo, a difference that was not statistically significant.

The FDA noted that gastrointestinal bleeding was more common with the drug, and it warned against combining it with certain medicines, including some seizure drugs, that strongly speed up how the body clears it. It is not recommended for people with moderate or severe liver disease, and patients should stop taking it at least 24 hours before elective surgery.

Cost may be a hurdle. A Bayer spokesperson put the list price at $748.50 for a 30-day supply, and BioPharma Dive noted that access could limit how quickly the drug is adopted. Bayer's U.S. leader told Reuters the company believes it is bringing a practice-changing innovation to patients.

As with any new medicine, patients should talk with their own doctor about whether it is right for them, and should not stop or switch any current medication without medical advice.

Stroke is one of the most common and devastating health emergencies in America. More than 795,000 people in the United States have a stroke each year, and about 185,000 of those, nearly one in four, happen to people who have had a stroke before, according to the Centers for Disease Control and Prevention. About 87% of strokes are ischemic, caused by a blocked blood vessel.

For families caring for a parent or grandparent after a first stroke, a treatment that meaningfully lowers the odds of a second one without adding much bleeding risk is genuinely good news.

Doctors urge everyone to learn the warning signs of a stroke, summed up as BE FAST, according to University of Iowa Health Care:

Balance: sudden loss of balance or coordination. Eyes: sudden loss of vision, or blurred or double vision. Face: one side of the face drooping or uneven. Arm: sudden weakness or numbness in an arm. Speech: slurred speech or confusion. Time: call 911 right away, and do not drive the person to the hospital yourself.

Every minute counts. Knowing these signs, and acting on them, can save a life.