Investigational Anticoagulant May be Cost-Effective

An investigational inhibitor of Factor XI being studied to prevent stroke and systemic embolism in patients with atrial fibrillation could result in potential cost-savings of $50,000 per patient and higher quality-adjusted life years (QALYs). An economic analysis of phase 2 data of abelacimab show this therapy, if approved, could be a cost-effective anticoagulant. The analysis was recently presented at the recent Professional Society for Health Economics and Outcomes Research (ISPOR) meeting.

Atrial fibrillation is an irregular and rapid heart rhythm. It can lead to blood clots in the heart and increases the risk of stroke, heart failure, and other complications. The CDC estimates that 12.1 million people in the United States will have atrial fibrillation by 2030. But about 40% to 60% of people with atrial fibrillation will not be prescribed an anticoagulant to prevent strokes and blood clots, or thrombosis because anticoagulants such as rivaroxaban can lead to bleeding.

Developed by Anthos Therapeutics, abelacimab is a highly selective human monoclonal antibody that binds to Factor XI and locks into an inactive state. This prevents the formation of the activated form Factor XI. If approved, abelacimab would be administered subcutaneously once a month.

The cost-effectiveness analysis was based on the results from the AZALEA-TIMI 71 phase 2 trial that was sponsored by Anthos Therapeutics. The trial found that abelacimab demonstrated a significant reduction in bleeding events.

AZEALEA TIMI-71 enrolled 1,287 patients with a moderate to high risk of ischemic stroke and evaluated the safety and tolerability of abelacimab. Patients were randomized to either abelacimab 150 mg or 90 mg administered monthly by subcutaneous injection or rivaroxaban daily. Rivaroxaban, marketed as Xarelto by Johnson & Johnson, is a direct-oral anticoagulant (DOAC) that is used to treat and prevent blood clots.

The findings from the AZALEA-TIMI 71 trial were presented in November 2023 at the American Heart Association Scientific Sessions meeting in Philadelphia.

Cost and utility estimates for the cost-effectiveness analysis were derived from literature and publicly available sources. The model used a three-month cycle length and a lifetime horizon, and a 3% annual discount rate was applied to both cost and utilities.

As a placeholder price, investigators in the cost-effectiveness analysis priced abelacimab on parity with the wholesale acquisition cost of Xarelto based on Redbook from 2023, which was $550 for a monthly supply. Abelacimab also assumed to have a one-time up-front training cost.

Investigators found that over a lifetime, on a per-person basis, abelacimab saved more than $50,000 and had 1.5 more QALYs compared with rivaroxaban. Total costs for abelacimab were $61,034 compared with $111,575 for rivaroxaban.

Abelacimab remained cost-effective at a price up to 20 times higher than rivaroxaban because of its ability to curb the risk for bleeding events.

Dan Bloomfield, M.D.

“The significantly improved bleeding profile favoring abelacimab as seen in the AZALEA-TIMI 71 study, coupled with the results from this new cost- effectiveness analysis means that, if approved, patients may have a safer, cost-saving treatment alternative as compared to a standard of care direct-oral anticoagulant,” Dan Bloomfield, M.D., chief medical officer at Anthos Therapeutics said in a news release.

The results of AZALEA-TIMI 71 that were presented at the American Heart Association found that the study met its primary endpoint of a 67% reduction in major or clinically relevant non major bleeding events compared with rivaroxaban. Additionally, the 150 mg dose resulted in 2.7% incidence of bleeding and the 90 mg dose resulted in 1.9% incidence of bleeding, compared with 8.1% incidence of bleeding in those treated with rivaroxaban. In the patients treated with abelacimab, there was a 93% reduction in major GI bleeding and a 74% reduction in major bleeding.

A data monitoring committee in September 2023 stopped the AZEALEA trial early because of its overwhelming reduction in bleeding events.

Previously, abelacimab achieved about an 80% reduction in venous thromboembolism (VTE) versus a standard-of-care comparator in a proof-of-concept efficacy study that was published in The New England Journal of Medicine.