City Therapeutics closed an upsized initial public offering on 19 October 2026, after underwriters exercised their over-allotment option in full — 12,777,777 shares at $18.00, for $230.0 million gross before expenses. The Cambridge, Massachusetts company's technology traces to a chemistry lab at Ohio State University, where researchers found a way to make RNA-interference drugs smaller, more stable and able to reach tissue the first generation of the medicine class could not.
A chemistry-department discovery becomes a Nasdaq ticker
From an Ohio State lab bench to CTY
- ~2020
The trigger chemistry is discovered
Kotaro Nakanishi, a professor of chemistry and biochemistry at Ohio State University, publishes findings on small, stable RNA molecules that activate the Argonaute-3 enzyme to cleave a target messenger RNA — a different trigger chemistry than the siRNA used in approved RNAi drugs.
- Summer 2023
City Therapeutics founded
Former Alnylam Pharmaceuticals founding CEO John Maraganore co-founds City with Nakanishi and other scientific collaborators, building a company around the Ohio State chemistry while based in Cambridge, Massachusetts.
- October 2024
Public launch, $135 million Series A
City launches publicly with a $135 million Series A led by ARCH Venture Partners, described at the time as the largest Series A to trace to Ohio State-derived research.
- January 2025
Andy Orth named CEO
Orth, who previously led the U.S. commercial launch of Alnylam's ONPATTRO, the first FDA-approved RNAi drug, joins as Chief Executive Officer; Maraganore moves to Executive Chairman.
- June 2026
$99.5 million Series B
New investors Viking Global Investors and Sofinnova Investments lead a Series B; City also discloses a neurological-disease collaboration with Biogen.
- 15–19 October 2026
Nasdaq IPO prices and closes
The offering upsizes and prices at $18.00 a share, then closes with the underwriters' option exercised in full for $230.0 million gross.
- Late 2026
More CITY-FXI Phase 1 data expected
Additional single-ascending-dose results for CITY-FXI, beyond the interim knockdown figures already reported.
City Therapeutics is not, strictly, an Ohio State University spinout in the formal technology-transfer sense — no licensing agreement between the university and the company turned up in the public record. What is well documented is the science: City is built on RNA "trigger" molecules discovered in Nakanishi's lab that activate a different enzyme, Argonaute-3, than the Argonaute-2 pathway every approved RNAi drug uses. The company says the result is a smaller, more stable trigger that is easier to chemically modify and conjugate to delivery molecules — the basis for City's stated goal of reaching tissues beyond the liver, where first-generation RNAi medicines are confined by their GalNAc delivery chemistry.
“I am proud to have joined the City Therapeutics team of RNAi pioneers as we push the category’s boundaries and deliver breakthrough therapeutic innovations for a range of diseases.” Andy Orth, Chief Executive Officer, City Therapeutics — 7 January 2025, on his appointment as CEO (not a statement about the IPO itself)
City's raise, in four figures
Figures from City Therapeutics' 15–19 October 2026 IPO pricing and closing announcements and its prior Series A/B financing announcements.
A clotting target five companies are chasing five different ways
CITY-FXI silences Factor XI, a clotting-cascade protein increasingly seen as a way to prevent stroke and venous blood clots without the bleeding risk that limits today's anticoagulants. The idea is not new, and City is a late, different-shaped entrant: Bristol Myers Squibb and Johnson & Johnson's milvexian and Bayer's asundexian are oral small molecules already in Phase 3 (Bayer halted its own atrial-fibrillation trial for asundexian on an inferiority signal, while a stroke-prevention trial continues); Anthos Therapeutics' abelacimab is a monthly injected antibody, also in Phase 3; Ionis and Bayer's fesomersen is an antisense oligonucleotide in Phase 2. City's RNAi candidate is the only one of the five built on gene-silencing chemistry, with the modality's characteristic trade-off: slower onset, but dosing that can stretch to once a quarter or longer once established.
Three things City is betting its chemistry can do
A different enzyme pathway
City's RNA triggers activate Argonaute-3, not the Argonaute-2 pathway every approved RNAi drug relies on — a chemistry the company says is smaller and more stable, developed from Kotaro Nakanishi's Ohio State research.
Built to leave the liver
First-generation RNAi drugs reach only the liver, via GalNAc delivery chemistry. City says its platform is designed to pair the same trigger chemistry with delivery ligands aimed at other tissues.
Three programs, three organs
CITY-FXI (blood, anticoagulation), CITY-RBP4 (eye, Stargardt disease) and CITY-TFR2 (anemia of chronic disease) span three different tissues on one platform — the test of the extra-hepatic claim before any one program reaches late-stage data.
What a Factor XI inhibitor is worth before one is approved
No Factor XI inhibitor of any modality has yet won approval anywhere, so every market estimate is necessarily a forecast built on a drug class that does not exist commercially yet. The narrowest, most relevant published figures come from The Business Research Company's Factor XIa Inhibitors Global Market Report, which estimated the class at $1.06 billion in 2025, growing to $1.24 billion in 2026 and $2.32 billion by 2030 — a forecast built entirely on pipeline assumptions, since the publisher has no sales to measure yet. One Citi Research analyst note cited in trade coverage floats a bull case above $50 billion by the mid-2030s if the class displaces a meaningful share of today's anticoagulant prescribing; we treat that as a scenario, not a market-research estimate, and do not use it as a published figure below.
Factor XI inhibitors, before a single approval
$1.06B → $2.32B
Factor XIa inhibitors, 2025 to 2030, as forecast by The Business Research Company (September 2026) — a pipeline-only class with no approved product yet.
Sources: The Business Research Company, Factor XIa Inhibitors Global Market Report, September 2026
Regulatory News outlook
We expect the Factor XI-inhibitor class, across every modality combined, to reach roughly $3 billion by 2032 as the first approvals land, with RNAi dosing carving out a minority share among once-daily oral and monthly-injected rivals that are further along in testing.
How we got here: The Business Research Company's $2.32 billion 2030 figure, compounded forward at the 16.8% annual rate the same report states, reaches about $3.2 billion by 2032; we assume RNAi takes a minority share of that total because City's CITY-FXI is still in Phase 1 while oral and antibody competitors are already in Phase 3.
CITY-FXI against the Factor XI field
| Program | Modality | Stage | Dosing |
|---|---|---|---|
| CITY-FXI (City Therapeutics) | RNAi (siRNA) | Phase 1 | Subcutaneous, infrequent once established |
| Milvexian (BMS / Johnson & Johnson) | Oral small molecule | Phase 3 | Once or twice daily |
| Asundexian (Bayer) | Oral small molecule | Phase 3 (AFib trial halted for inferiority; stroke trial continues) | Once daily |
| Abelacimab (Anthos Therapeutics) | Monoclonal antibody | Phase 3 | Monthly subcutaneous |
| Fesomersen (Ionis / Bayer) | Antisense oligonucleotide | Phase 2 | Subcutaneous, infrequent |
From each company's own disclosures and public trial registrations; not a clinical comparison. No Factor XI inhibitor of any modality is yet approved.
What the raise still has to prove
City's own disclosures put roughly $30 million of the pre-upsize raise toward CITY-FXI's clinical development and $20 million toward CITY-RBP4, figures reported before the offering was upsized to $230 million; the company has not published a revised breakdown for the larger total, so a reader should treat the original split as directional rather than final. The Phase 1 trial behind CITY-FXI, registered as NCT07430397, is a single-ascending-dose study at a single UK site, with a reported 128-participant ceiling; secondary reporting describes knockdown of Factor XI exceeding 60% after a 15 mg dose and around 85% three weeks after a 150 mg dose, though we could not independently verify those figures against a City Therapeutics release.
- More Phase 1 data: additional single-ascending-dose results for CITY-FXI are expected in late 2026, ahead of any dose-selection decision for a larger trial.
- CITY-RBP4: the Stargardt disease program was described in mid-2026 as approaching an investigational new drug application, with a target of entering the clinic by the end of 2026.
- Cash runway: secondary reporting on the pre-upsize raise put the company's cash runway into 2028; City has not published an updated runway figure reflecting the final $230 million.
- Crowded field, different clock: three Factor XI programs are already in Phase 3; City's RNAi candidate is years behind on data but, if it works, offers the least-frequent dosing of the five.
What the closing announcement does not say: an exact, final-total use-of-proceeds breakdown, a post-upsize cash-runway estimate, or any new clinical data beyond what the company had already disclosed before pricing. CITY-FXI remains a Phase 1 program; nothing in this raise moves it closer to proof that silencing Factor XI is both safe and effective at preventing clots in a real patient population, which only a larger trial can show.
Sources & further reading
- City Therapeutics, “City Therapeutics Announces Closing of $230.0 Million Upsized Initial Public Offering, Including Full Exercise of Underwriters’ Option to Purchase Additional Shares,” 19 October 2026. globenewswire.com
- City Therapeutics, “City Therapeutics Announces Pricing of Upsized Initial Public Offering,” 15–16 October 2026. nasdaq.com
- RTTNews, “City Therapeutics Prices Upsized $200 Mln IPO At $18/Shr,” 15 October 2026. rttnews.com
- pharmaphorum, “RNAi biotech City hauls in $200m in upsized IPO,” October 2026. pharmaphorum.com
- Fierce Biotech, “City goes public with $200M IPO, while Frazier Life Sciences takes biotech-focused SPAC to Nasdaq,” October 2026. fiercebiotech.com
- City Therapeutics, “City Therapeutics Appoints Andy Orth as Chief Executive Officer,” 7 January 2025. businesswire.com
- ClinicalTrials.gov, study record NCT07430397 (CITY-FXI Phase 1). clinicaltrials.gov
- The Business Research Company, Factor XIa Inhibitors Global Market Report, September 2026 (via Research and Markets). researchandmarkets.com
Regulatory News reports on public regulatory documents. It is not legal advice, and the primary sources above govern. If we have made an error, we will say so in public: see corrections.
Frequently asked questions
How much did City Therapeutics raise in its IPO?
$230.0 million gross, after the underwriters exercised their over-allotment option in full for 12,777,777 total shares at the $18.00 IPO price. The offering priced 15 October 2026 and closed 19 October 2026 on the Nasdaq Global Market under the ticker CTY.
What is CITY-FXI?
An investigational RNAi (small interfering RNA) therapy that silences Factor XI, a blood-clotting protein, aimed at preventing stroke and venous blood clots without the bleeding risk of standard anticoagulants. It is in Phase 1 dosing studies; no clinical efficacy has yet been established.
Is City Therapeutics an Ohio State University spinout?
Its founding science is: City licenses RNA-trigger chemistry discovered in Professor Kotaro Nakanishi's chemistry lab at Ohio State. The company itself is headquartered in Cambridge, Massachusetts, co-founded in 2023 by Nakanishi and former Alnylam CEO John Maraganore, and launched publicly in October 2024 with a $135 million Series A.
What else is in City's pipeline?
CITY-RBP4, targeting Stargardt disease, and CITY-TFR2, targeting anemia of chronic disease, both earlier-stage than CITY-FXI. The company has also disclosed a neurological-disease collaboration with Biogen.
