Suzhou Ribo Life Science Co., Ltd. (RIBOLIFE-B) has filed a Phase 2b clinical-trial application (CTA) with the European Medicines Agency for vortosiran (RBD4059), its lead small-interfering RNA (siRNA) therapy aimed at preventing venous thromboembolism (VTE).

The submission forms part of a broader clinical program that will evaluate vortosiran across several thromboembolic cardiovascular indications. VTE affects an estimated 10 million patients globally each year and remains a leading cause of cardiovascular morbidity and mortality; existing anticoagulants are often under-utilised or discontinued due to bleeding risks.

Vortosiran targets factor XI (FXI), aiming for selective and durable inhibition of the FXI-mediated coagulation pathway to reduce clotting activity while mitigating bleeding concerns. According to the company, vortosiran is the most advanced siRNA-based FXI inhibitor in clinical development. A Phase 2a study in coronary artery disease in Europe has been completed, and a separate Phase 2b CTA for atrial fibrillation was filed with the EMA in April 2026.

Management cautions that vortosiran may ultimately not achieve successful development or commercialisation. Shareholders and prospective investors are advised to exercise caution when dealing in the company’s shares.