Recent advances in factor XI (FXI) inhibition are reshaping the landscape of anticoagulation therapy
Recent advances in factor XI (FXI) inhibition continue to reshape the landscape of anticoagulation therapy and thrombosis prevention. We acknowledge the positive results from the phase III OCEANIC-STROKE study of asundexian in secondary stroke prevention, demonstrating that FXI inhibition can significantly reduce the risk of stroke. Interest in this therapeutic area is further accelerating, supported by this encouraging new clinical data.
As a company actively advancing FXI inhibition through siRNA-based therapeutics, Ribo is committed to developing the next generation of safe and effective anticoagulant treatments. Our leading position in this field is highlighted in a recently published scientific review (https://doi.org/10.1007/s40256-025-00787-0)
We have also published our Phase 1 data from the first‑in‑human study of our GalNAc‑conjugated small interfering RNA (siRNA) candidate, Vortosiran (RBD4059), targeting FXI (https://doi.org/10.1182/bloodadvances.2025018348). The results show a robust, dose‑dependent, and durable suppression of FXI activity exceeding 90%. Moreover, Vortosiran maintain sustained clinically meaningful FXI inhibition for up to six months or longer, underscoring its potential to meaningfully improve treatment adherence in chronic anticoagulation.
We are also excited to announce that our Phase 2a program has completed last patient last dose and final data will be shared at upcoming cardiovascular congress during 2026. The overall Vortosiran clinical program is progressing according to plan, aiming for exploration of multiple clinical indications and positioning Vortosiran as the most advanced siRNA for FXI inhibition in development today.
We remain committed to advancing FXI siRNA inhibition toward a safer standard of care in anticoagulation.

