Abelacimab, an experimental anti-clotting drug, was effective at lowering bleeding in people with atrial fibrillation (A-Fib) who were at risk of having a stroke compared with a competing drug, according to new research.
The drug, which was developed by Anthos Therapeutics, cut the overall risk of bleeding by 67% compared with rivaroxaban (Xarelto).
Results of the phase 2 trial were presented at the American Heart Association’s Scientific Sessions 2023 over the weekend.
Abelacimab is an injectable monoclonal antibody known as a factor XI inhibitor.
The study involved comparing bleeding in 1,287 people taking either 90 milligrams or 150 milligrams of abelacimab compared with people taking 20 milligrams a day of the anticoagulant rivaroxaban. Participants came from 95 global study sites in the United States and Canada, Europe and Asia. The researchers followed up on people for 1.8 years after they took the medications. All of the participants were aged 55 or more years, and up and 44% were women; they all had a moderate to high risk for stroke.
Researchers stopped the AZALEA-TIMI 71 trial prematurely in September because of the “overwhelming reduction” in bleeding with abelacimab compared with rivaroxaban.
Abelacimab significantly reduced bleeding among people with A-Fib that typically would require medical attention (but not hospitalization) by 67% in those taking 150 milligrams and by 77% in those taking 90 milligrams, compared with rivaroxaban. In people who took 150 milligrams, abelacimab lowered major bleeding by 74%, and major bleeding was reduced by 81% in people who took 90 milligrams, compared with rivaroxaban. Both doses of abelacimab reduced gastrointestinal bleeding by 93% compared with rivaroxaban.
For the most part, abelacimab was well-tolerated. Similar rates of adverse events were seen compared with rivaroxaban.
“This trial confirms the promise of abelacimab to be an incredibly safe anticoagulant for stroke prevention in people with A-Fib,” Christian T. Ruff, MD, director of general cardiology at Brigham and Women’s Hospital in Boston, senior investigator for the TIMI Group and an associate professor of medicine at Harvard Medical School, said in a statement.
