FDA greenlights Sunharbo — a first-of-its-kind drug to prevent repeat strokes

The FDA has approved Sunharbo (asundexian, Bayer) — the first factor XIa (FXIa) inhibitor ever approved — to reduce the risk of recurrent stroke in adults who recently experienced a non-cardioembolic ischemic stroke or high-risk transient ischemic attack (TIA). The once-daily 50 mg tablet is designed to be used alongside antiplatelet therapy and works by dampening thrombin amplification to reduce clot formation while having a smaller impact on normal blood clotting.

The approval was based on the phase 3 OCEANIC-STROKE trial, which enrolled 12,327 patients within 72 hours of a qualifying stroke or TIA. Over a median 14.2 months of treatment, Sunharbo reduced ischemic stroke risk by 26% compared to placebo, without a statistically significant increase in major bleeding. Secondary outcomes — including cardiovascular death, MI, or stroke — also improved significantly.

By the Numbers:

• 26% reduction in recurrent ischemic stroke risk vs. placebo
• 6.2% vs. 8.4% — ischemic stroke rates in the Sunharbo vs. placebo groups
• ~1 in 10 stroke survivors experience a second stroke within 1 year; ~1 in 5 within 5 years
• Higher major bleeding risk noted in patients >75 years (2.6 vs. 1.7 per 100 patient-years) and during the first 90 days of treatment (4.5 vs. 3.1 per 100 patient-years)

Why it matters: Secondary strokes are often more severe than the first, and existing therapies leave patients at substantial residual risk. Sunharbo offers clinicians a novel mechanism to address that gap — particularly for the ~45% of global strokes that are non-cardioembolic — without the major bleeding burden seen with traditional anticoagulants.