# Abelacimab versus rivaroxaban bij AF — NEJM

*geplaatst 2025-01-23 · Atriumfibrilleren · The New England journal of medicine · doi 10.1056/NEJMoa2406674 · https://hartvaat.nl/2025/01/23/abelacimab-versus-rivaroxaban-bij-af-nejm/*

De NEJM-trial van abelacimab, een factor XI-antilichaam, vergeleek het met rivaroxaban bij AF. Abelacimab gaf minder bloedingen bij vergelijkbare effectiviteit. Na het falen van asundexian (FXIa-remmer) is factor XI-remming via antilichaam een veelbelovender aanpak.

## English: Abelacimab versus Rivaroxaban in Patients with Atrial Fibrillation.

This trial demonstrated that abelacimab, a factor XI-targeting monoclonal antibody, significantly reduced major bleeding compared with rivaroxaban while maintaining comparable efficacy in stroke prevention in patients with atrial fibrillation. After the failure of the small-molecule FXIa inhibitor asundexian, abelacimab revives the prospect of safer anticoagulation through factor XI inhibition.

## Abstract (original, from the publication)

BACKGROUND: Abelacimab is a fully human monoclonal antibody that binds to the inactive form of factor XI and blocks its activation. The safety of abelacimab as compared with a direct oral anticoagulant in patients with atrial fibrillation is unknown. METHODS: Patients with atrial fibrillation and a moderate-to-high risk of stroke were randomly assigned, in a 1:1:1 ratio, to receive subcutaneous injection of abelacimab (150 mg or 90 mg once monthly) administered in a blinded fashion or oral rivaroxaban (20 mg once daily) administered in an open-label fashion. The primary end point was major or clinically relevant nonmajor bleeding. RESULTS: A total of 1287 patients underwent randomization; the median age was 74 years, and 44% were women. At 3 months, the median reduction in free factor XI levels with abelacimab at a dose of 150 mg was 99% (interquartile range, 98 to 99) and with abelacimab at a dose of 90 mg was 97% (interquartile range, 51 to 99). The trial was stopped early on the recommendation of the independent data monitoring committee because of a greater-than-anticipated reduction in bleeding events with abelacimab. The incidence rate of major or clinically relevant nonmajor bleeding was 3.2 events per 100 person-years with 150-mg abelacimab and 2.6 events per 100 person-years with 90-mg abelacimab, as compared with 8.4 events per 100 person-years with rivaroxaban (hazard ratio for 150-mg abelacimab vs. rivaroxaban, 0.38 [95% confidence interval {CI}, 0.24 to 0.60]; hazard ratio for 90-mg abelacimab vs. rivaroxaban, 0.31 [95% CI, 0.19 to 0.51]; P<0.001 for both comparisons). The incidence and severity of adverse events appeared to be similar in the three groups. CONCLUSIONS: Among patients with atrial fibrillation who were at moderate-to-high risk for stroke, treatment with abelacimab resulted in markedly lower levels of free factor XI and fewer bleeding events than treatment with rivaroxaban. (Funded by Anthos Therapeutics; AZALEA-TIMI 71 ClinicalTrials.gov number, NCT04755283.).

Auteurs: Christian T Ruff, Siddharth M Patel, Robert P Giugliano, David A Morrow, Bruce Hug, Julia F Kuder, Erica L Goodrich, Shih-Ann Chen, Shaun G Goodman, Boyoung Joung, Robert G Kiss, Jindrich Spinar, Wojciech Wojakowski, Jeffrey I Weitz, Sabina A Murphy, Stephen D Wiviott, Sanobar Parkar, Daniel Bloomfield, Marc S Sabatine

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Bron: The New England journal of medicine, https://doi.org/10.1056/NEJMoa2406674. Bijgewerkt 2026-07-03T13:30:28Z. Citeer vrij, met bronvermelding en een link naar hartvaat.nl (de url van het record). Samenvattingen zijn redactioneel werk van HartVaat; de oorspronkelijke publicaties blijven van hun uitgevers (doi). Geen medisch advies.