Aug. 31, 2024 - Gothenburg - Kunshan - Beijing

Suzhou Ribo Life Science Co., Ltd. (Ribo) announced that the first clinical data from its completed Phase I study of the world′s first and most advanced hemostasis-sparing antithrombotic Factor XI (FXI) targeting siRNA asset, RBD4059, have been presented at ESC (European Society of Cardiology) Congress 2024 in London on August 31, 2024.

As reported, RBD4059 demonstrated dose dependent, predictable PK, and pronounced (>90%) and durable FXI activity and protein reduction in the dose range of 50 mg - 600 mg. Primary endpoint for safety and tolerability has been met - RBD4059 demonstrated favorable safety profile with no identified adverse safety signals across the investigated dose-range.

This first-in human study supports the further development of RBD4059 as an anticoagulant that can maintain a high level of PD effect with every 3- or 6-months dosing regimen, with potential for enhanced compliance and low bleeding risk in chronic anti-coagulant therapy.

Anticoagulants are essential for the prevention and treatment of thrombosis, addressing a wide range of indications including coronary artery disease, peripheral artery disease, end-stage renal disease (ESRD), atrial fibrillation (AF), venous thromboembolism (VTE), postoperative orthopedic surgery etc.  Current anticoagulants often suffer from short duration of action and high dosing frequency, coupled with bleeding risks, highlighting the urgent need for potent, long-acting anticoagulants with lower bleeding risks.

RBD4059, discovered and developed by Ribo based on its proprietary RIBO-GalSTAR^TM technology platform, is an innovative GalNAc-conjugated siRNA drug, which achieves anticoagulant / antithrombotic effects by inhibiting FXI and blocking the activation of the intrinsic coagulation pathway. Compared to existing antithrombotic therapies, RBD4059 offers the advantages of stronger efficacy, longer duration of action and lower bleeding risk as an siRNA drug.

Previously, RBD4059 received approval from the European Medicines Agency (EMA) for a randomized, double-blind, placebo-controlled Phase IIa clinical trial, aimed at evaluating the safety, pharmacokinetics, and pharmacodynamics of repeated subcutaneous injections of the drug in patients with stable coronary artery disease. The first patient was enrolled in August 2024.

Dr. Li Ming Gan, Co-CEO and Global Head of R&D at Ribo, remarked: "We are excited to have progressed world’s first and most advanced FXI siRNA program, now into PhaseⅡ, based on these encouraging data from Phase Ⅰ. The molecule fulfills the target product profile we set up to achieve in terms of clinically meaningful and relevant potency and duration, which clearly differentiates from all established anti-thrombotic therapies as well as profiles of all other FXI inhibition programs in clinical development, including small molecules and antibodies. Also, we are extremely encouraged to see the low inter-individual variability in treatment response, which further strengthens the first- and best-in-class potential of the program. We look forward to continuing the further clinical development of RBD4059 based on the encouraging Phase Ⅰ results, and it's believed it will bring a transformative change to the current anti-thrombotic therapy."