Abelacimab for the Treatment of Stroke Prevention in Atrial Fibrillation (SPAF): An Early Cost-Effectiveness Analysis (CEA) Versus Rivaroxaban from 5 European Country Perspectives

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, a safety study, evaluated the bleeding profile of the Factor XI inhibitor abelacimab, a monthly-dosed fully human monoclonal antibody, relative to rivaroxaban in patients with AF. This analysis explored the potential cost-effectiveness of abelacimab versus rivaroxaban from France, Germany, Italy, Spain (EU4) and United Kingdom (UK) national health system perspectives.

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 due to a significant benefit favoring abelacimab across all bleeding endpoints; results at early study end were used for this analysis. Since AZALEA-TIMI 71 was a safety study, the model assumed no difference in risk of stroke or myocardial infarction. The cost of rivaroxaban was sourced from national drug pricing databases; as a placeholder, abelacimab was priced at parity to rivaroxaban. Event costs and utilities were derived from publicly available sources. Total costs and quality-adjusted life years (QALYs) were compared over a lifetime.

RESULTS: Abelacimab was dominant (i.e., lower costs, higher QALYs) versus rivaroxaban across all five countries. Over a lifetime, on a per-person basis, treatment with once-monthly abelacimab resulted in improvements of 1.3-1.5 QALYs and cost savings of €392-693 (EU4) and ₤7,347 (UK) compared to daily-dosed rivaroxaban. Results were robust in one-way sensitivity analyses across all five countries.

CONCLUSIONS: This is the first analysis assessing the potential cost-effectiveness of abelacimab, an investigational once-monthly, Factor XI inhibitor for people with AF at moderate-to-high risk of stroke, from five European country perspectives. If approved, abelacimab could yield substantial cost savings.