FDA Approves Sunharbo, the First Factor XIa Inhibitor, to Prevent a Second Stroke at a $748.50 List Price
Bayer's once-daily pill cut ischemic stroke by about a quarter in 12,327 patients without a clear rise in major bleeding. What the label says, and what the trial left open.
Thursday, November 12, 2026/2 min read
A new kind of blood thinner has reached the American market. On Monday 9 November the FDA approved Sunharbo (asundexian), made by Bayer, as the first factor XIa inhibitor cleared in the United States, for adults who have had a recent stroke or a high-risk warning episode and need to avoid a second one.
The approval is narrow and the evidence behind it is a single large trial. Here is what the agency authorised, what the trial found and what it did not settle, as it stood on the morning of Thursday 12 November.
What did the FDA approve Sunharbo for?
According to the FDA announcement, the 50 mg once-daily tablet is approved alongside antiplatelet therapy to reduce stroke risk after a recent mild-to-moderate ischemic stroke not caused by a clot from the heart, or after a high-risk transient ischemic attack. It is not approved for stroke prevention in atrial fibrillation. The agency had granted Fast Track and Priority Review.
BioPharma Dive reported that Bayer will list a 30-day supply at $748.50, a list price that is not necessarily what insurers or patients pay. The same report notes that the drug stumbled in a separate atrial fibrillation study.
What did the OCEANIC-STROKE trial show?
The pivotal trial randomised 12,327 adults within 72 hours of symptoms to asundexian or placebo, with everyone on antiplatelet drugs. In the results published in the New England Journal of Medicine and summarised by Practical Neurology, ischemic stroke occurred in 6.2 percent of the asundexian group and 8.4 percent of the placebo group, a cause-specific hazard ratio of 0.74.
Major bleeding, the main safety measure, was 1.9 percent against 1.7 percent, a difference that was not statistically significant. The confidence interval was wide, though, running from a small reduction to roughly a 44 percent increase in relative risk. The benefit in the first 90 days alone did not reach significance either.
What are the risks and limits on the label?
The FDA says overall major bleeding was similar to placebo, but it was higher in patients older than 75 and during the first 90 days of treatment, and gastrointestinal bleeding was more common. Diarrhea was the most frequent adverse reaction. The label does not recommend use with strong combined P-gp and CYP3A4 inducers such as carbamazepine, or in moderate or severe liver impairment, and the drug should be withheld at least 24 hours before elective surgery.
Questions remain about how it compares with existing options, how long benefit lasts and how insurers will treat it. An accompanying editorial, as summarised by Practical Neurology, argued that follow-up of years rather than months is needed to judge net benefit.
This is reporting, not medical advice. Decisions about stroke prevention, antiplatelet drugs and any anticoagulant belong with a clinician who knows the reader's history, including bleeding risk and other medicines.
The next markers are the product's US launch and any coverage decisions, plus how rival factor XIa drugs perform in their own trials.
Published in The Outspoken Digest
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