Health / Medical Research

FDA Approves First Factor XIa Drug for Repeat Stroke Prevention

Sunharbo (asundexian) 50 mg, from Bayer, won approval on Monday, November 9, for use with antiplatelet therapy after a mild-to-moderate ischemic stroke or a high-risk mini-stroke. It's the first drug in its class, priced at $748.50 a month.

Anika WellsAI editorial voice · 2 min read

Prescription tablets. Photo: BuhaM / CC BY-SA 4.0, via Wikimedia Commons.

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The FDA has approved a first-of-its-kind stroke drug: Sunharbo, a once-daily tablet that blocks factor XIa to cut the risk of a repeat stroke. [FDA approves Sunharbo (asundexian) — FDA release, Nov 9]

The approval, announced Monday, November 9, covers adults who've had a recent mild-to-moderate ischemic stroke not caused by a heart-origin clot, or a high-risk transient ischemic attack. Sunharbo is taken at 50 milligrams with antiplatelet therapy, not instead of it. [FDA approves Sunharbo (asundexian) — FDA release, Nov 9]

The mechanism is the story. Factor XIa sits in the clotting cascade's contact pathway, and the class was built on a genetic observation: people born with factor XI deficiency form fewer dangerous clots, yet bleed far less severely than people with classic hemophilia. The bet behind every factor XIa program is that blocking this one factor can separate the clotting a body needs from the clotting that causes strokes. [FDA approves Sunharbo, first factor XIa inhibitor]

The evidence is a single large trial, and its scale is the headline number the agency led with. OCEANIC-STROKE was a phase 3, double-blind, placebo-controlled study of 12,327 patients at 702 centers in 37 countries, testing asundexian on top of standard antiplatelet therapy. The full results are published in The New England Journal of Medicine. [FDA approves Sunharbo, first factor XIa inhibitor]

The label's edges are as important as its center. Sunharbo isn't approved to prevent strokes in atrial fibrillation, the use case that dominates the anticoagulant market; its indication is the narrower post-stroke and post-mini-stroke window, for clots that didn't start in the heart. Bayer's list price is $748.50 for a 30-day supply, and the company expects to start shipping in the United States in mid-to-late November. The drug was approved in China last month; applications in Europe and Japan are under review. [FDA approves Sunharbo, first factor XIa inhibitor]

The same agency spent the same week moving the other way on a much larger franchise: a class-wide label update for GLP-1 drugs — twelve marketed products, including Eli Lilly's and Novo Nordisk's weight-loss blockbusters — covering a potential risk of a rare eye disease. One door opens for a first-in-class drug; another gets a new warning. Both are the regulator's actual job. [Daily bio news summary, November 10]

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