ABELACIMAB, a novel Factor XI inhibitor, significantly reduces the risk of bleeding in patients with atrial fibrillation compared to rivaroxaban, regardless of kidney function, according to new results from the AZALEA-TIMI 71 trial. This effect may be particularly beneficial for individuals with impaired renal function, a group at high risk from standard anticoagulation.
Patients with atrial fibrillation frequently require anticoagulant therapy to prevent strokes, but those with chronic kidney disease face increased bleeding risk, complicating treatment decisions. Rivaroxaban and similar anticoagulants are often dose-adjusted for kidney function, yet bleeding rates remain elevated in those with renal impairment. Researchers have sought alternative therapies that could lower these risks without sacrificing protection against stroke.
The AZALEA-TIMI 71 study randomised 1,284 adults with atrial fibrillation to monthly abelacimab or daily rivaroxaban, including both standard and dose-reduced regimens for those with poor kidney function, defined as creatinine clearance of 50 mL/min or less. Median patient age was 74 years, and over 20 percent had reduced kidney function at baseline. In the rivaroxaban group, major or clinically relevant nonmajor (CRNM) bleeding occurred at a rate of 13.6 per 100 person-years for those with kidney impairment, compared with 7.0 per 100 person-years for healthier kidneys. Abelacimab, by contrast, reduced bleeding rates to 0.26 times those of rivaroxaban for impaired kidneys and 0.40 times for others, with consistent risk reduction seen in all related outcomes. Absolute bleeding risk fell by 10.1 and 4.2 events per 100 person-years for impaired and preserved kidney function, respectively.
The evidence points to abelacimab as a safer option for anticoagulation in patients with chronic kidney disease. Clinicians treating atrial fibrillation should be aware of these differences and consider emerging therapies that may offer improved safety with equal efficacy.
Reference
Patel SM et al. Safety of factor XI inhibition with abelacimab in atrial fibrillation by kidney function: a prespecified analysis of the AZALEA-TIMI 71 randomized clinical trial. JAMA Cardiol. 2025;DOI:10.1001/jamacardio.2025.3393.
