The number of Americans with irregular heartbeats, known as atrial fibrillation, is expected to top 12 million people by the end of the decade. This heart condition can frequently lead to blood clots and put patients at risk for strokes, which is why they’re often prescribed blood thinning medications. But the downside of anticoagulants is that they can, in some patients, exacerbate bleeding to a dangerous degree.
A number of companies are working on new types of anticoagulants to help avoid this issue so that more people can take them. One of them is Blackstone-backed Anthos Therapeutics, which has developed a monoclonal antibody called abelacimab that binds to Factor XI, an important clotting agent. The company just published results of its phase 2 clinical trials, which found that abelacimab had a 67% lower risk of bleeding compared to standard anticoagulants, while still being effective at preventing clotting and without any significant adverse events. That’s impressive considering that the best case scenario before the trial started was a 40% reduction, said Christian Ruff, the principal investigator of the trial. “That’s great news for us, and more importantly great news for patients.”
Anthos’ Chief Medical Officer Dan Bloomfield told Forbes that the company’s next steps are to move into phase three clinical trials, with results from those expected in mid-2025. If the phase 2 results hold up, he says, the company’s medication could be potentially approved and on the market by 2026, barring any unforeseen events. “These could become the dominant anticoagulants,” he said.
