Two Biotechs, One Window: Iambic and Cambridge’s City Therapeutics Test the Fall IPO Market

NORTH MYRTLE BEACH, S.C. — October 14, 2026 — The fall IPO calendar has been a graveyard of postponements. Rising Treasury yields, a jittery AI trade and geopolitical noise have pushed one issuer after another to the sidelines. Yet this week two drug developers are walking straight into that weather, together. Iambic Therapeutics, a San Diego company that designs cancer drugs with artificial intelligence, and City Therapeutics, a Cambridge, Massachusetts, RNA interference developer, are each seeking roughly $150 million to $185 million on Nasdaq. Between them, they are asking public investors to value two very different bets at a combined $1.7 billion or so.

Neither had announced final pricing in the reporting we reviewed as of Wednesday morning. What follows is what their filings and the IPO trackers show, and what it means for the healthcare capital markets Paxton-Digital follows every day.

The two deals, side by side

• Iambic Therapeutics (proposed: IAM). 9.4 million shares at $15 to $17, or about $150 million at the midpoint. Renaissance Capital puts the fully diluted market value near $809 million at the midpoint; Reuters calculated up to $805.8 million based on shares outstanding. Bookrunners: J.P. Morgan, Jefferies, BofA Securities and Citi. Expected to price the week of Oct. 12.
• City Therapeutics (proposed: CTY). 9.72 million shares at $17 to $19, or about $175 million at the midpoint and up to $184.7 million at the top. IPOScoop estimates a market cap near $906 million at the midpoint. Bookrunners: Goldman Sachs, Jefferies, Stifel and Oppenheimer. Pricing is expected after the market close on Thursday, Oct. 15, according to a launch report from MedPath.

Iambic: the AI-discovery test case

Founded in 2019 under the name Entos by CEO Tom Miller and CTO Fred Manby, Iambic pairs proprietary AI models with automated, high-throughput chemistry and biology labs. Models propose molecules, robots make and test them, and the results feed back into the models. Its lead program, IAM1363, is an oral, brain-penetrant HER2 inhibitor in Phase 1/1b testing for HER2-altered solid tumors. Behind it sit IAM217, a KIF18A inhibitor entering the clinic, and IAM-C1, a dual CDK2/CDK4 inhibitor.

The partnership list is long. Takeda signed a multiyear platform deal in February worth up to $1.7 billion in milestones, AbbVie announced a collaboration in September, according to Fierce Biotech, and Nvidia is both a backer, per Reuters, and a listed partner. ARK Investment Management and Duquesne Family Office have indicated interest in buying about $60 million of the offering, roughly 40% of the deal, Reuters reported. Iambic had about $207.9 million in cash at the end of June and says the IPO would fund operations through the end of 2028. Its filing earmarks about $75 million of proceeds for IAM1363.

City Therapeutics: Cambridge’s RNAi pedigree

City was founded in July 2023 and is led by John Maraganore, the founding CEO of Alnylam, the company that turned RNA interference into approved medicines. Its lead candidate, CITY-FXI, is a GalNAc-conjugated siRNA that silences Factor XI, a target the industry is chasing for safer blood thinners. Phase 1 data are expected in late 2026, with a Phase 2 study in total knee replacement patients planned for mid-2027. Two earlier programs target Stargardt disease and anemia of chronic disease.

City has collaboration agreements with Biogen and Bausch + Lomb, reported a net loss of about $87.7 million on $14.3 million of collaboration revenue for the 12 months ended June 30, and held roughly $141.9 million in cash as of Sept. 30 after a $99.5 million Series B in June at $14.63 a share. That last number matters: the IPO range sits comfortably above the Series B price, a step-up recent private investors will be watching closely.

What is confirmed, and what is not

Share counts, price ranges, ticker symbols, bookrunners and pipeline details come from the companies’ SEC filings as reported by at least two outlets each. Market-value figures are third-party estimates and differ by methodology. The Oct. 15 pricing date for City comes from a single launch report and could move. Final prices, deal sizes and first-day trading are unknown until the deals close.

Paxton-Digital’s Take

This is a two-question exam for the window. Iambic asks whether public investors will pay up for an AI-built pipeline whose lead asset is still in Phase 1. City asks whether a proven RNAi playbook and a famous founder are worth a near-billion-dollar valuation before mid-stage data. Different questions, same answer key: price discipline.

Anchor demand changes the math. Sixty million dollars of indicated interest from ARK and Duquesne de-risks Iambic’s book in a market where many deals cannot get started. Indications are not orders, but they signal to the rest of the book that the deal will clear.

Watch the step-up. For City, pricing near or above the midpoint would validate the June Series B. Pricing below the range would tell every RNAi and cardiometabolic startup in Kendall Square something less pleasant about where crossover money stands this fall.

The bigger signal is plural. One biotech IPO is a data point. Two in the same week, alongside TRex Bio and Retension Pharmaceuticals pricing on Oct. 8, starts to look like a pipeline of issuers that believe the window is open for quality. For healthcare M&A, that matters too: a healthy IPO exit raises every target’s walk-away price.

Discussion questions

• Should an AI-discovery platform earn a valuation premium before it has mid-stage clinical data?
• Does a founder’s track record, like Maraganore’s at Alnylam, justify a higher IPO price?
• If both deals price well, which healthcare sectors are next to test the public markets?

Sources

• Nvidia-backed Iambic Therapeutics launches IPO as biotechs buck market gloom — Reuters (via Investing.com)
• Iambic Therapeutics sets terms for $150 million IPO — Renaissance Capital
• AI biotech Iambic aims for $135M IPO — Fierce Biotech
• City Therapeutics sets terms for $175 million IPO — IPOScoop
• City Therapeutics IPO: RNAi biotech seeks up to $185 million — Quartz
• City Therapeutics launches IPO to fund RNAi pipeline — MedPath
• Health Care IPOs — Renaissance Capital

Featured image: AI-generated illustration (DeepAI). This article is for information only and is not investment advice.