City Therapeutics has raised $99.5 million in Series B financing to advance its next-generation RNA interference therapeutics platform and expand its clinical pipeline. The Cambridge, Massachusetts-based biopharmaceutical company said the round included new participation from Viking Global Investors and Sofinnova Investments, alongside a broad group of existing life sciences investors. The financing strengthens the company’s position as it works to develop RNAi-based medicines for serious diseases across multiple therapeutic areas.
City Therapeutics Secures New Growth Capital
The Series B round brings additional capital to support City Therapeutics’ RNAi engineering platform, pipeline development, and business development activities. New investors Viking Global Investors and Sofinnova Investments joined Casdin Capital and NYBC Ventures, as well as existing backers including ARCH Venture Partners, Fidelity Management & Research Company, Invus, Slate Path Capital, Rock Springs Capital, Regeneron Ventures, AN Ventures, and other undisclosed investors. The company has now raised more than $230 million from leading life sciences investors since its founding.
City Therapeutics plans to use the proceeds to accelerate multiple programs, including its ongoing Phase 1 clinical trial of CITY-FXI. The therapy targets Factor XI, known as FXI, and is being developed for the treatment of thromboembolic diseases. The company also intends to move two additional programs into the clinic by the end of 2026, including CITY-RBP4, an RNAi candidate for Stargardt disease.
Advancing RNAi-Based Medicines
RNA interference is a biological mechanism that can be used to silence disease-causing genes, offering a targeted approach to treating a range of conditions. City Therapeutics is focused on expanding the reach of RNAi medicines through a platform designed to improve engineering, delivery, and therapeutic application across new tissue types. Its pipeline reflects the company’s goal of building differentiated programs that could address areas where existing treatment options remain limited.
The company recently reported positive preclinical data for CITY-RBP4, which it describes as a potentially first-in-class RNAi therapy for Stargardt disease. Stargardt disease is an inherited retinal disorder that can lead to progressive vision loss, making it an area of significant unmet medical need. By advancing CITY-RBP4 toward the clinic, City Therapeutics is seeking to demonstrate the potential of its platform beyond more established RNAi applications.
Leadership Highlights Clinical and Strategic Progress
Andy Orth, chief executive officer of City Therapeutics, said the financing reflects the company’s progress since its Series A round two years ago. He pointed to several milestones, including the advancement of CITY-FXI into clinical testing and the completion of strategic collaborations with Bausch + Lomb and Biogen. Orth said the new funding positions the company to move two programs into clinical development this year and continue validating its RNAi platform.
John Maraganore, Ph.D., co-founder and executive chairman of City Therapeutics, said the round underscores the team’s mission to lead the next generation of RNAi-based medicines. He highlighted the company’s work to expand RNAi beyond traditional boundaries and into new programs and tissue types. Maraganore also emphasized that the platform’s progress reflects the broader potential of RNAi technology to create meaningful advances for patients.
Investor Support and Board Participation
As part of the financing, Rohan Nirody, managing director at Viking Global Investors, and Maha Radhakrishnan, M.D., executive partner, private equity at Sofinnova Investments, will join City Therapeutics’ board of directors as observers. Their involvement adds further life sciences and investment expertise as the company expands its clinical and platform activities. The addition of new board observers also signals continued investor confidence in City Therapeutics’ scientific strategy and development plans.
Nirody said City Therapeutics has assembled a highly experienced RNAi team and is pursuing a compelling scientific vision. He noted that Viking Global shares the company’s belief that RNAi can transform treatment for serious diseases. The investor support provides City Therapeutics with both financial resources and strategic backing as it advances programs through clinical development.
City Therapeutics’ $99.5 million Series B financing marks a significant step in the company’s effort to build a broader pipeline of next-generation RNAi therapeutics. With CITY-FXI already in Phase 1 testing and additional programs moving toward the clinic, the company is entering a more active stage of clinical execution. Backed by a strong syndicate of new and existing investors, City Therapeutics aims to expand the reach of RNAi medicines and deliver new treatment options for patients with serious diseases.