City Therapeutics
Cambridge, US · 88 employees on LinkedIn · 13 known investors
City Therapeutics develops RNAi-based medicines targeting rare, specialty, and prevalent diseases using engineered trigger molecules and precision delivery ligands. The company aims to expand RNAi therapeutics beyond liver targeting to additional cell and tissue types.
Also known as City Therapeutics, Inc. · City Tx · CityTx
Founders & leadership
Investors · 13
Also in the syndicate · 6
Funding
SEC filings, press & company announcements$99.5M disclosed across 1 of 3 rounds · 2024–2026
- $99.5MSeries BJun 2026 · 5 sources
Sofinnova Investments (lead), Viking Global Investors (lead), AN Ventures, ARCH Venture Partners, Casdin Capital, Fidelity Management and Research Company, Invus, NYBC Ventures, Regeneron Ventures, Rock Springs Capital, Slate Path Capital
Source ↗
Source: company announcements and press reports — follow each round's link for the claim.
Company profile
researched Aug 2026City Therapeutics, Inc. is a Cambridge, Massachusetts-based biotechnology company developing RNA interference (RNAi)-based medicines that silence disease-causing gene expression by targeting and degrading messenger RNA. The company's platform has two components: engineered RNAi trigger molecules designed for potency, specificity, durability and cellular uptake through chemistry, sequence and length — including proprietary "cleavage-inducing tiny (city) RNAs" — and precision targeting ligands intended to deliver siRNAs to a broader range of cell and tissue types than current RNAi medicines, extending beyond hepatic delivery to ocular, CNS and additional tissues.
The disclosed pipeline spans discovery through early clinical stages. CITY-FXI is an RNAi candidate targeting coagulation Factor XI for thromboembolic diseases, intended to prevent clots without increasing bleeding risk and, based on preclinical duration of effect, to support an infrequent dosing schedule. CITY-RBP4 targets RBP4, a liver-produced protein that transports vitamin A to the eye, with the goal of slowing or halting progression of Stargardt disease and geographic atrophy. Additional programs include an undisclosed hepatic target ("Target 3"), an undisclosed CNS program and an undisclosed ocular program for geographic atrophy. As of 2026 the company reported having initiated a Phase 1 trial of CITY-FXI and expected to move two programs into the clinic during the year.
Founding story
The company states it was founded by pioneers of the RNAi field. Sebastian Trousil, PhD, is a co-founder and chief operating officer, previously at RTW Investments and Flagship Pioneering, where he led company-creation efforts, and a co-founder of liquid biopsy company Harbinger Health. John Maraganore, PhD, is co-founder and executive chairman and was described in 2024-2025 press coverage as leading the newly launched RNAi company.
Business model
Biopharmaceutical R&D company advancing a proprietary siRNA engineering platform and an internal pipeline of drug candidates, complemented by partnered programs with larger pharmaceutical companies. Caplight characterizes the company as B2B in the healthcare and life sciences sector.
No product revenue is described in the sources. The company has entered strategic collaborations with Bausch + Lomb (reported potential value of $485 million-plus) and Biogen (reported at up to $1 billion), which trade press describes as strategic validation; deal economics beyond these headline figures are not disclosed in the sources.
Traction
Caplight reports total funding of $264.5 million and an employee count of 79; FinSMEs reports over $230 million raised from life sciences investors. Operational milestones include two announced pharma collaborations (Bausch + Lomb, Biogen), a CTA submission and initiation of a Phase 1 trial for CITY-FXI, preclinical data for CITY-RBP4, and management guidance of two programs reaching clinical stage in 2026.
Latest developments
In June 2026 the company closed a $99.5 million Series B led by Viking Global Investors and Sofinnova Investments, with proceeds directed to pipeline advancement, platform acceleration and business development; Rohan Nirody (Viking Global) and Maha Radhakrishnan (Sofinnova) joined the board as observers. In August 2026 City Therapeutics appointed Keith Regnante, MBA, as chief financial officer and Mary Beth DeLena, J.D., as chief legal officer.
▸Full profile — market position, technology, go-to-market, geography, history, risks & controversies
Market position
The company positions itself within an RNAi field that has produced seven FDA-approved therapies since 2018, arguing that more than 200 cell types remain untargeted. Caplight lists Sanegene Bio, Atalanta Therapeutics and Suzhou Ribo Life Science as most similar companies by embedding similarity. Its founding team and executive chairman John Maraganore are described in press coverage as pioneers of the RNAi field.
Emphasis on combining engineered trigger molecules with novel targeting ligands to extend RNAi beyond hepatic delivery into ocular, CNS and other tissues, together with foundational intellectual property around new trigger chemistries such as cleavage-inducing tiny (city) RNAs and a leadership team with long-standing RNAi experience.
Technology
Next-generation RNAi trigger molecule engineering combined with tailored targeting ligands for delivery. Triggers are designed for enhanced potency, specificity and cellular uptake through chemistry, sequence and length, and include proprietary cleavage-inducing tiny (city) RNAs that cleave target mRNA to silence gene expression. Delivery work spans foundational hepatic conjugate delivery and proprietary extrahepatic delivery to ocular, CNS and other tissue types.
Go-to-market
Advancing internal programs toward IND/CTA and clinical stage while entering strategic research and development collaborations with established pharmaceutical companies to apply the RNAi platform to selected targets and tissue types; Series B proceeds are earmarked in part for business development.
Patients with rare, specialty and prevalent diseases addressable by gene silencing, including thromboembolic disease, Stargardt disease (more than 30,000 people in the United States; roughly 1 in 8,000 globally) and geographic atrophy (approximately 5 million people worldwide). Pharmaceutical partners such as Bausch + Lomb and Biogen are counterparties for platform collaborations.
Geography
Headquartered in Cambridge, Massachusetts, with offices in Kendall Square; the company describes itself as an intentionally in-person organization.
History
Caplight lists a founding year of 2024. The company launched publicly on 2024-10-08 with a $135 million Series A led by ARCH Venture Partners. Andy Orth was appointed chief executive officer in January 2025, the same month the Bausch + Lomb geographic atrophy collaboration was announced. The executive team and board were expanded in April 2025, and a Biogen research collaboration followed in May 2025, alongside a convertible debt round dated 2025-05-27. A Clinical Trial Application for CITY-FXI was submitted in November 2025, preclinical CITY-RBP4 data were presented at ARVO in May 2026, and a $99.5 million Series B closed on 2026-06-08. In August 2026 the company appointed Keith Regnante as chief financial officer and Mary Beth DeLena as chief legal officer.
Risks & controversies
No controversies are reported in the available sources. Standard development-stage risk is implied: the pipeline is preclinical to early clinical, several programs and targets remain undisclosed, and no approved products or revenues are described. Reported total funding figures differ between sources ($264.5 million per Caplight versus over $230 million per FinSMEs).
Compiled by commissioned research from 8 cited public sources — announcements, filings, and press listed under research sources below.
Key figures
latest reportedCompany-reported or press-reported figures, each dated to when it was claimed — not independently audited.
Founder mafia
2 people who came through City Therapeutics went on to found or lead other companies.
Competitors · 2
by search overlap
Companies competing with City Therapeutics for the same Google search keywords, organic and paid, via search-intersection analysis.
Timeline · 9
launches, deals, and filingsSeries B led by new investors Viking Global Investors and Sofinnova Investments, with Casdin Capital, NYBC Ventures and existing backers ARCH Venture Partners, Fidelity Management & Research Company, Invus, Slate Path Capital, Rock Springs Capital, Regeneron Ventures and AN Ventures. Proceeds are intended to advance the RNAi pipeline, accelerate the next-generation RNAi engineering platform and support business development. Rohan Nirody (Viking Global) and Maha Radhakrishnan (Sofinnova) joined the board as observers.
$99.5M source ↗
City Therapeutics presented preclinical data on CITY-RBP4, an investigational next-generation RNAi therapy for Stargardt disease, at the ARVO 2026 Annual Meeting.
The company announced submission of a Clinical Trial Application for CITY-FXI, an investigational RNAi therapeutic for thromboembolic diseases.
City Therapeutics and Biogen announced a strategic research collaboration to develop select novel RNAi-based therapies; trade press reported the deal as worth up to $1 billion.
$1B source ↗
City Therapeutics announced a strategic collaboration with Bausch + Lomb to develop a novel RNAi-based treatment for geographic atrophy; trade press described the pact as worth $485 million-plus in potential milestones.
$485M source ↗
City Therapeutics publicly launched with a $135 million Series A financing to develop next-generation RNAi-based medicines; the round was led by ARCH Venture Partners. Press coverage described the company as led by John Maraganore.
$135M source ↗
Dated company events from announcements, filings, and press; legal rows summarize public dockets and regulator releases.
In the news
▸Research sources · 8
primary sources listed
- City Therapeuticscitytx.com · web
8 public sources were cited for this profile; the first-party ones are listed here.
Frequently asked questions
- What does City Therapeutics do?
- Cambridge, MA biotech engineering next-generation RNAi trigger molecules and delivery ligands to reach tissues beyond the liver.
- Who founded City Therapeutics?
- City Therapeutics was founded by Mark Keating, MD, Kotaro Nakanishi, PhD, Yukihide Tomari, PhD, Phillip Zamore, PhD.
- Who are City Therapeutics's investors?
- City Therapeutics's investors include AN Venture Partners, ARCH Venture Partners, Sofinnova Ventures, Casdin Capital, Fidelity Investments, Invus, Rock Springs Capital.
- How much funding has City Therapeutics raised?
- City Therapeutics has disclosed $99.5M raised across 1 of its 3 known rounds.
- Where is City Therapeutics headquartered?
- City Therapeutics is headquartered in Cambridge, US.