Bayer wins first Asundexian nod in China

Bayer has obtained marketing approval in China for its anticoagulant Asundexian to lower the high risk of further events in stroke patients. The Chinese regulator has cleared the drug, marketed as Sunharbo, for the prevention of secondary strokes in patients who have previously experienced an ischemic stroke or a high-risk transient ischemic attack. This marks the first marketing authorization worldwide for Asundexian, which had not been approved in any country before this decision.

According to Bayer, Asundexian is the first medicine from the new class of FXIa inhibitors to reach the market. The drug targets the FXIa protein involved in blood clot formation and is intended for use alongside agents that prevent platelet aggregation. Clinical results show that preventive administration of Asundexian reduces the risk of additional ischemic strokes by 26 percent in patients with a prior stroke.

The FXIa mechanism is designed to deliver anticoagulation while maintaining a lower bleeding risk than currently available blood thinners. Bayer highlights that Asundexian is expected to have a reduced bleeding risk compared with established oral anticoagulants. The company positions the therapy for patients in whom ischemic events often arise from mechanisms where a careful balance between thrombosis prevention and bleeding side effects is required.

Ischemic stroke is described as the leading cause of death and disability in China, underscoring the size of the patient population. Despite existing prevention strategies, roughly one in ten survivors of a non‑cardioembolic ischemic stroke experiences another stroke within one year. Bayer’s head of pharmaceutical research, Christian Rommel, called the approval an important milestone that addresses an area of unmet need with few therapeutic advances over the past two decades.

China granted Asundexian a shortened or accelerated review pathway, speeding its route to market. The approval is based in part on data from the Oceanic-Stroke study, which showed a clear reduction in ischemic stroke risk when Asundexian was combined with platelet aggregation inhibitors in patients with a previous stroke. The decision makes China the first country to authorize a drug from the FXIa inhibitor class.

Bayer is pursuing additional approvals for Asundexian, with regulatory procedures under way in the United States, Europe and Japan. The Chinese launch represents the initial market entry for a drug class that has not previously been part of routine clinical practice. The company’s strategic focus has shifted more strongly toward stroke prevention after a Phase III study in atrial fibrillation patients with stroke risk was halted in 2023 due to lack of efficacy.

Asundexian is viewed by Bayer and analysts as a potential blockbuster capable of generating billions in annual revenue over time. It is described as a prospective successor to the former blockbuster Xarelto in the important Chinese market for secondary stroke prevention. With this approval, Bayer’s pharmaceutical division gains a new potential growth driver.

The company aims for Asundexian to help offset continued revenue declines in Xarelto and the eye drug Eylea, which face competition from generic products after patent expiries. On the day of the announcement, Bayer’s shares were temporarily among the strongest performers in the DAX index, reflecting investor interest in the commercial prospects of the new FXIa inhibitor now entering the Chinese market.