City Therapeutics, a buzzy biotechnology startup working on new types of RNA interference therapies, secured $200 million in an initial public offering on Thursday.
City sold just over 11.1 million shares at $18 apiece, more than it had expected when setting projections earlier this week. It will begin trading on the Nasdaq on Friday under the ticker symbol “CTY.”
Co-founded by longtime Alnylam Pharmaceuticals CEO John Maraganore, City is one of many young companies aiming to take RNA interference technology — a way of silencing genes before they can make harmful proteins — in new directions. Though eight RNAi medicines have been approved by regulators, most are used to treat rare diseases and all are aimed at genetic targets in the liver.
Newer technical advances have emboldened companies to broaden RNAi’s reach. Some are focusing on more common conditions, while others are trying to send RNAi drugs into different tissue types, like the brain or lungs.
City is working on a mix of both. The top three drugs in its pipeline, for instance, are directed at liver targets. Yet they’re for a combination of chronic conditions — like clotting disorders and anemia — and degenerative eye diseases.
The company’s most advanced candidate is dubbed CITY-FXI and aims at the blood-clotting protein Factor XI. Like other Factor XI-targeting drugs in development, City’s prospect is designed to prevent “thromboembolic” diseases, when blood clots form, spring loose and cause harm. It’s also supposed to lower the risk of bleeds, a safety hazard associated with existing medications.
City plans to develop the therapy in multiple indications, including secondary stroke prevention, atrial fibrillation and cancer-associated thrombosis. Phase 1 testing has shown an ability to drop Factor XI levels by as much as 85%. The company’s first Phase 2 trial, expected next year, will involve people who have a higher risk of a postoperative clot following a knee replacement.
The company’s second most advanced candidate is for Stargardt disease, a genetic eye condition several biotechs are targeting with oral drugs, gene therapies and other approaches. Called CITY-RBP4, it mutes a gene that produces “RBP4,” a protein that shepherds vitamin A to the eye. It’ll enter a Phase 1 clinical trial later this year, and should produce results in 2027.
City is exploring CITY-RBP4’s use in other eye diseases, including geographic atrophy, too.
A third City program is for a particularly common form of anemia that occurs when long-term illnesses trigger chronic inflammation. This “anemia of chronic disease” affects over five million people in the U.S., the company said. An early-stage study is coming in 2027. City may eventually test it in other disorders where anemia is prevalent, such as chronic kidney disease.
Beyond those therapies is earlier research meant to expand the reach of RNAi treatments “across new tissues, targets and disease areas,” City said in its filing. Partnerships with Bausch + Lomb and Biogen are part of that effort. So are two programs built around tiny, synthetic RNAs that City believes to have certain advantages over traditional RNAi approaches.
Prior to its IPO, City raised about $239 million in venture funding from Arch Venture Partners, Fidelity Management & Research and Invus, among others.