Ribo Bio Unveils First-in-Class FXI-Targeting siRNA Anticoagulant RBD4059 with Promising Phase I Data at ESC Congress 2024

On August 31, 2024, Suzhou Ribo Life Science Co., Ltd. ("Ribo Life Science") presented the Phase I clinical study data of RBD4059, the world’s first small nucleic acid drug targeting anticoagulant Factor XI (FXI) from its self-developed pipeline, in a conference report at the ESC Congress 2024 London hosted by the European Society of Cardiology. The main findings are as follows:

RBD4059 demonstrated dose-dependent, predictable pharmacokinetic properties, along with significant (>90%) and sustained reductions in FXI activity and protein levels; meanwhile, it met the primary endpoints for safety and tolerability, with no adverse safety signals identified within the studied dose range, exhibiting favorable safety.

This study will support the further development of RBD4059 as an anticoagulant drug. It maintains a high level of pharmacodynamic (PD) effects in dosing regimens of every 3 months or 6 months, which is expected to achieve higher compliance and lower bleeding risk in chronic anticoagulation therapy.

Anticoagulant drugs are fundamental for the prevention and treatment of thrombosis, with a wide range of indications including coronary artery disease, peripheral artery disease, end-stage renal disease (ESRD), atrial fibrillation (AF), venous thromboembolism (VTE), and post-operative care in orthopedic surgeries. Current anticoagulants have limitations such as short efficacy duration, high dosing frequency, and carry a certain risk of bleeding. Therefore, there is a significant clinical demand for new anticoagulants that are potent, long-lasting, and associated with a low risk of bleeding.

RBD4059 is a product of Ribo Life Science based on RIBO-GalSTAR.^TMRBD4059, a GalNAc-conjugated siRNA drug independently developed by the liver-targeting technology platform with global rights, achieves its anticoagulant/antithrombotic effects by inhibiting FXI and blocking the activation of the intrinsic coagulation pathway. Compared with current antithrombotic treatment methods, RBD4059, as an siRNA drug, has the advantages of being more potent, long-lasting, and carrying a lower risk of bleeding.

Previously, a randomized, double-blind, placebo-controlled Phase IIa clinical trial of RBD4059 has been approved by the European Medicines Agency (EMA). This trial aims to evaluate 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. Gan Liming, Co-CEO of Ribo Life Science and President of Global R&D, stated:"We have obtained exciting Phase I clinical data, and we are very excited to advance this world's first and most clinically advanced FXI-targeted siRNA drug, RBD4059, into Phase II clinical trials. The efficacy and duration demonstrated by RBD4059 in the clinic have met our pre-set Target Product Profile (TPP), which clearly distinguishes it from all other globally marketed anticoagulant therapies and all other FXI inhibitors currently in clinical development, including small molecules and antibodies. At the same time, we are highly encouraged by the consistency of treatment responses among the subjects, further solidifying the drug’s potential as a First-In-Class and Best-In-Class therapy."

Ribo Life Science will continue to spare no effort in advancing the clinical development of RBD4059, bringing more precise and effective treatment options to patients worldwide. We look forward to the future performance of this innovative drug and believe it will bring significant changes to the field of antithrombotic therapy.