American Society of Hirudotherapy

RE-LY Trial — Dabigatran vs Warfarin in Atrial Fibrillation

Landmark trial establishing leech-inspired oral anticoagulant dabigatran for stroke prevention

Last Updated: March 18, 2026Reviewed by: ASH Editorial Board
Research article — evidence reviewArticle reference
Drug DevelopmentConnolly SJ et al. · New England Journal of Medicine, 2009

Summary

The RE-LY (Randomized Evaluation of Long-Term Anticoagulation Therapy) trial compared dabigatran — a direct thrombin inhibitor inspired by leech hirudin — against warfarin for stroke prevention in atrial fibrillation. The trial (n=18,113) demonstrated non-inferiority and, at higher doses, superiority over warfarin with lower intracranial hemorrhage rates.

Why This Matters for Hirudotherapy

Dabigatran represents the most transformative drug to emerge from leech biology. This NEJM landmark trial led to FDA approval and fundamentally changed anticoagulation practice. It is the definitive example of bench-to-bedside translation from leech salivary pharmacology.

Citation

Dabigatran versus Warfarin in Patients with Atrial Fibrillation

Connolly SJ et al. · New England Journal of Medicine, 2009

DOI

Added to ASH library: March 18, 2026 · Site last updated: March 18, 2026

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RE-LY Trial — Dabigatran vs Warfarin in Atrial Fibrillation | ASH