Biologic demonstrates “tremendous” potential advance in atrial fibrillation

US researchers have shown that the Factor XI inhibitor abelacimab significantly reduced bleeding in patients with atrial fibrillation compared to a standard-of-care anticoagulant, rivaroxaban.

The AZALEA-TIMI 71 Phase II trial is the largest and longest trial investigating a Factor XI inhibitor compared to standard of care direct oral anticoagulants to date. The study was stopped early based on this significant reduction in bleeding compared to standard-of-care.

Participants were given monthly injections of 150mg abelacimab, 90mg abelacimab, or standard dosing of rivaroxaban (20mg or 15mg in dose reduced patients).

Potentail of abelacimab for bleeding events

Findings from the study showed that 150mg dose of abelacimab reduced bleeding that required hospitalisation or medical attention by 62 percent, compared with rivaroxaban. The 90mg dose of abelacimab reduced the same types of bleeding by 69 percent.

Additionally, both doses of abelacimab almost eliminated gastrointestinal bleeding compared to rivaroxaban, the data showed. This bleeding is most common type observed in patients taking anticoagulants, the researchers highlighted.

Furthermore, stroke rates in the study were low. No significant differences between patients given abelacimab versus rivaroxaban were identified, according to Ruff et al.

Addressing unmet needs in atrial fibrillation

“It should be enormously satisfying to the cardiovascular field, patients and providers that Factor XI inhibitors live up to their promise of superior safety,” stated Dr Christian Ruff, MPH, Director of General Cardiology within the Cardiovascular Division at Brigham and Women’s Hospital, a founding member of the Mass General Brigham healthcare system, senior investigator in the TIMI Study Group and principal investigator of the AZALEA-TIMI 71 Study. “Atrial fibrillation is a common medical condition, and bleeding with currently available anticoagulants resulting in significant undertreatment is still one of the greatest shortcomings in cardiovascular disease.”

“The AZALEA-TIMI 71 study validated that Factor XI inhibitors have an incredibly safe bleeding profile in patients with atrial fibrillation, which is a tremendous potential advance for our patients,” explained Dr Christian Ruff. “Now we can shift our attention as we await the results of the Phase III trials.”

This new data was published in the New England Journal of Medicine.