Home

City Therapeutics Announces Submission of Clinical Trial Application for CITY-FXI, an Investigational RNAi Therapeutic for the Treatment of Thromboembolic Diseases

via Business Wire

Company plans to initiate a Phase 1 study in early 2026 with initial human data expected late 2026

Company’s first clinical-stage program headlines a diverse and novel pipeline poised to deliver 1-2 new investigational drugs into the clinic annually

City Therapeutics, Inc., a biopharmaceutical company leading the future of RNA interference (RNAi)-based medicine, today announced the submission of a Clinical Trial Application (CTA) to the UK Medicines and Healthcare Products Regulatory Agency (MHRA) to initiate a Phase 1 study of CITY-FXI, an investigational RNAi therapeutic targeting Factor XI (FXI). CITY-FXI is intended to be a safe and effective anticoagulant with reduced bleeding risk compared to today’s standard of care therapies.

“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.”

Safe and effective anticoagulation remains a significant unmet medical need, with thrombosis responsible for approximately one in four deaths worldwide. Despite advances in treatment, the current standard-of-care anticoagulants have been associated with substantial bleeding risks and challenges with patient adherence, leaving many patients inadequately protected.

“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.”

In preclinical studies, CITY-FXI demonstrated substantial potency, durability and specificity with no off-target effects observed to date. Upon CTA clearance, City Therapeutics plans to initiate a Phase 1 clinical trial.

About City Therapeutics

City Therapeutics is a biopharmaceutical company harnessing its next-generation RNAi platform to improve and expand the reach of RNAi-based medicines. The company is building a pipeline of innovative RNAi therapeutics to make a significant impact for patients across multiple therapeutic areas. Co-founded by pioneering executives and scientists in RNAi, City Therapeutics is based in Cambridge, MA, and has raised $135 million from leading life sciences investors. For more information, please visit us at www.citytx.com and follow us on LinkedIn.

Contacts