Abelacimab provides greater protection against bleeding in older AF patients

Abelacimab consistently reduces the risk of bleeding in patients with atrial fibrillation (AF) regardless of age, with the risk reduction seemingly greater for those with older age, according to the phase IIb AZALEA-TIMI 71 trial.

AZALEA-TIMI 71 included 1,287 AF patients (55.6 percent male). These patients were randomly assigned to receive subcutaneous abelacimab at 90 or 150 mg monthly or oral rivaroxaban at 20 mg daily (with dose reduced to 15 mg if creatinine clearance was ≤50 mL/min). The primary endpoint was the composite of major or clinically relevant nonmajor bleeding.

Of the patients, 662 were in the <75-year age group (median 69 years) and 625 were in ≥75-year age group (median 79 years). Compared with younger patients, those in the ≥75-year age group had lower BMI (28 vs 32 kg/m²), were less likely to be taking antiplatelet therapy at baseline (17 percent vs 32 percent), and were more likely to have creatinine clearance of 50 mL/min or less (33 percent vs 8 percent).

Both abelacimab doses were associated with significantly reduced risk of the primary endpoint compared with rivaroxaban in the ≥75-year age group (90 mg vs rivaroxaban: hazard ratio [HR], 0.32, 95 percent confidence interval [CI], 0.17–0.60; 150 mg vs rivaroxaban: HR, 0.40, 95 percent CI, 0.22–0.73) and in the ≤75-year age group (90 mg vs rivaroxaban: HR, 0.28, 95 percent CI, 0.12–0.61; 150 mg vs rivaroxaban: HR, 0.35, 95 percent CI, 0.17–0.70).

The absolute risk reductions appeared to be greater among patients aged ≥75 years (7.1 and 6.2 per 100 patient-years for abelacimab 90 and 150 mg vs rivaroxaban, respectively) than among those aged <75 years (4.7 and 4.2 per 100 patient-years, respectively).

In continuous age analysis, bleeding risk tended to increase with age with rivaroxaban group but remained stable with abelacimab.

The findings suggest that FXI inhibition with abelacimab may be a particularly attractive option in older patients with AF and higher bleeding risk.