OBJECTIVES: Despite advances in therapy for atrial fibrillation (AF), risk of bleeding remains high, leaving 40-60% of patients either untreated or undertreated with an anticoagulant. AZALEA-TIMI 71 was a safety study evaluating the bleeding profile of the dual-acting FXI/FXIa inhibitor abelacimab relative to rivaroxaban in patients with AF. This analysis explored the potential cost-effectiveness of abelacimab versus rivaroxaban from a US-payer perspective.

METHODS: A Markov model was developed reflecting clinical pathways typical of people with AF at moderate-to-high-risk of stroke. AZALEA-TIMI 71 was stopped early by the Data Monitoring Committee (DMC) due to a significant benefit favoring abelacimab across all bleeding endpoints; results at early study end were used for this analysis. For the primary endpoint, abelacimab 150mg once-monthly demonstrated a 67% lower rate of major or clinically relevant non-major bleeding compared with once-daily rivaroxaban 20mg (p<0.0001). Since AZALEA-TIMI 71 was a safety study, the model assumed no difference in risk of stroke or MI. The wholesale acquisition cost of rivaroxaban was sourced from REDBOOK (December 2023); as a placeholder, abelacimab was priced at parity to rivaroxaban. Event costs and utilities were derived from publicly available sources. A scenario analysis explored the value-based price of abelacimab using the 95% confidence interval of the primary bleeding endpoint. Total costs and quality-adjusted life years (QALYs) over a lifetime were compared.

RESULTS: Abelacimab was dominant (i.e., lower costs, higher QALYs) versus rivaroxaban. Over a lifetime, on a per-person basis, abelacimab saved over $50,000 and had 1.5 more QALYs compared to rivaroxaban. Using 0.19-0.55 for the relative risk of bleeding events, abelacimab remained cost-effective at a price up to 20 times higher than rivaroxaban.

CONCLUSIONS: This is the first analysis assessing the cost-effectiveness of abelacimab, an investigational once-monthly, dual-acting FXI/FXIa inhibitor for people with AF at moderate-to-high risk of stroke. If approved, abelacimab could yield substantial cost savings.