Undecimal Bio raises $18M seed to take RNA medicines beyond the liver

Undecimal Bio, a Cambridge spin-out from Eleven Therapeutics, has raised an $18M oversubscribed seed round co-led by 4BIO Capital and IQ Capital to deliver siRNA medicines to tissues beyond the liver, starting with renovascular disease.

Gene silencing is one of the rare corners of biotech where the science has stopped being the argument. The chemistry works and the drugs are approved – and yet almost every siRNA medicine in the clinic ends up in the same organ. The field calls it the liver trap, and on 13 October 2026 a Cambridge team raised $18M to spring it.

Below, I lay out the round, the platform behind it, and why European RNA money keeps flowing to delivery rather than discovery.

An oversubscribed seed aimed at the liver trap

Undecimal Bio announced its $18M seed round on 13 October 2026, co-led by 4BIO Capital and IQ Capital, with Verve Ventures, Harel Technology Investments, Entrée Capital, Kerna Ventures and Saras Capital participating. The company describes the round as oversubscribed. Representatives of 4BIO Capital, IQ Capital and Harel join the board alongside co-founders Yaniv Erlich and Shaul Ilan, with Verve Ventures taking an observer seat.

The money goes where the name points: expanding the DELiveri delivery platform, advancing the company’s first programmes in renovascular disease and growing the team at its laboratories at the Cancer Research UK Cambridge Institute.

Half of Eleven Therapeutics, all of the delivery problem

Undecimal is one half of a deliberate split. Eleven Therapeutics, the RNA company it spun out from, divided itself in two this year: ScionxBio launched in July to carry long-acting RNA medicines for cardiometabolic disease forward, while Undecimal keeps the siRNA delivery platform, the Cambridge laboratories and a set of research collaborations with large pharmaceutical companies it has not yet named. Yaniv Erlich, who co-founded Eleven, leads the new company as CEO, and the team works across Cambridge and Tel Aviv.

The platform pairs large-scale combinatorial chemistry with transformer-based AI, then sets agentic AI loose on the structure-activity data that comes back. The company says DELiveri is validated in vivo and screens chemical spaces at a pace conventional medicinal chemistry cannot match. “The hard problem in RNAi was never the silencing, it was getting the molecule to the right cell,” Erlich said in the announcement.

The first stop is renovascular disease – conditions of the blood vessels supplying the kidneys where, in the company’s words, today’s treatments mostly manage symptoms rather than causes.

A $14.3bn market that rarely leaves one organ

So why does a field this proven still raise seed money for delivery? Because the market is growing faster than its reach. Global antisense and RNAi therapeutics stood at $5.1bn in 2024 and are forecast to reach $14.3bn by 2030, a 19.0% CAGR over 2025-2030 (Grand View Research, July 2026 update). That growth has been built overwhelmingly on liver-targeted drugs; Undecimal’s pitch is that the next phase belongs to whoever can give siRNA a different address.

The round also lands inside a visible European cluster. In the past three weeks our database has logged Aptadir’s €40M seed for switching silenced genes back on and Sensible Biotechnologies’ $47M Series A for cell-made mRNA. At $18M, Undecimal sits comfortably in that band – large for a European seed, unremarkable for an RNA platform play, where the tooling is the product.

Delivery is becoming a European speciality

What we are seeing is a pattern, not a coincidence. European investors are funding the infrastructure of RNA medicine rather than single assets: Aptadir, Sensible and now Undecimal are all platform rounds, none a bet on one molecule. The reality is that Europe rarely wins the single-asset race against Boston’s war chests. The good news is that platforms compound differently – a conjugate that reliably reaches the kidney matters to every payload owner in the field, wherever they raised.

Cambridge keeps stacking the evidence. The same week this round closed, CMR Surgical took $400M from Stryker a few miles from Undecimal’s lab bench. And look at the cap table’s geography: UK specialists co-leading, Tel Aviv institutions alongside, Swiss money observing. The UK-Israel corridor in deep bio is quietly becoming one of Europe’s more productive partnerships.

What to watch now: the first disclosed target, and whether those unnamed pharma collaborations convert into signed partnerships once DELiveri shows a conjugate that lands where it is pointed. The silencing is solved; the addressing is not. The companies working on the address rather than the message are where European RNA money is flowing – watch the kidney.