The Factor XI inhibitor movement hit a setback last week, after Bayer announced that it halted its OCEANIC-AF trial due to asundexian’s lack of efficacy.
- Investigative Factor XI inhibitors have sparked optimism among cardiologists for their potential to become safer antithrombotics, avoiding anticoagulants’ typical bleeding risks
- Asundexian is Bayer’s most advanced Factor XIa inhibitor, and already gained two FDA Fast Track Designations (stroke & systemic embolism prevention in Afib patients, stroke prevention after non-cardioembolic ischemic stroke)
The phase III OCEANIC-AF trial was intended to evaluate asundexian against BMS’ popular anticoagulant apixaban (Eliquis) among 18,000 Afib patients with higher stroke risks.
- The study was designed to measure asundexian’s effectiveness in preventing stroke or systemic embolism
- However, an Independent Data Monitoring Committee (IDMC) recommended OCEANIC-AF’s termination just eleven months after enrollment began due to asundexian’s “inferior efficacy” versus apixaban
Bayer didn’t provide more details on the results that prompted the IDMC’s recommendation, but as one prominent cardiologist with a large public platform noted: “To have it stopped this early must have meant there was a serious signal of lack of efficacy.”
Asundexian continued to achieve the safety benefits that Factor XI inhibitors are known for, with similar bleeding reductions as the previous PACIFIC-AF trial.
Despite this setback, the IDMC still recommended that Bayer continue with its OCEANIC-STROKE phase III trial evaluating asundexian’s ability to prevent ischemic stroke in patients who previously experienced a stroke.
- Bayer will also continue to evaluate “other indications in patients in need of antithrombotic treatment.”
There will also be more eyes on other investigative Factor XI inhibitors from Anthos Therapeutics and Janssen/Bristol Myers Squibb, noting that Anthos’s recent AZALEA-TIMI phase II trial also showed impressive bleeding reductions versus rivaroxaban, but more strokes.
The Takeaway
Some might see this as a sign that Factor XI’s “anticoagulation without bleeding risks” value proposition was too good to be true. However, it’s very possible that different Factor XI and Factor XIa inhibitors have different mechanisms, while the scientific learnings from this setback might actually lead to progress for the overall Factor XI drug class.
