CAMBRIDGE, Mass. — City Therapeutics, Inc., a biopharmaceutical company developing RNA interference (RNAi)-based medicines, announced it has submitted a Clinical Trial Application to the UK Medicines and Healthcare Products Regulatory Agency to begin a Phase 1 study of CITY-FXI, an investigational RNAi therapy targeting Factor XI. The therapy is being developed as a potential anticoagulant designed to lower bleeding risk compared to current standard-of-care treatments. The company anticipates beginning the Phase 1 trial in early 2026, with initial human data expected later that year.
“This CTA filing marks our transition to a clinical-stage company and underscores our team’s ability to move rapidly and effectively to move our product candidates into the clinic,” said Andy Orth, chief executive officer of City Therapeutics. “Our long-term strategy is to leverage our differentiated RNAi platform to build a deep and diverse pipeline of high-value clinical programs. We have the expertise, insight and differentiated science to lead the next wave of RNAi breakthroughs.”
Thromboembolic disease remains a significant unmet medical need, with thrombosis contributing to roughly one in four deaths worldwide. While treatment options have improved, many patients continue to face bleeding risks and challenges with adherence under current anticoagulant therapies.
“Low FXI levels are associated with protection from many thromboembolic diseases such as deep vein thrombosis, pulmonary embolism and stroke,” said Baisong Mei, M.D., Ph.D., chief medical officer of City Therapeutics. “A large body of evidence suggests that FXI knockdown via RNAi is potentially the most direct and efficacious way to suppress FXI production and protect against thrombosis. CITY-FXI is designed to address a critical need for patients who need long-term, safe and effective anticoagulation.”
Preclinical data for CITY-FXI have shown strong potency, durability and specificity, with no off-target effects observed to date. Pending clearance of the Clinical Trial Application, City Therapeutics plans to initiate the Phase 1 study.
