Alethio Therapeutics Raises €80.46M Series A for Blood Cancer Drugs

Oxford spin-out Alethio Therapeutics has closed an oversubscribed €80.46 million ($90 million / £67 million) Series A to take its targeted blood cancer therapies into the clinic.

Sofinnova Partners and RA Capital co-led the round as new investors. Founding investor Oxford Science Enterprises joined them, with additional support from Cancer Research Horizons and the University of Oxford. Graziano Seghezzi, Managing Partner at Sofinnova Partners, and Maxwell DeNies of RA Capital have taken seats on Alethio's Board of Directors.

The money has a precise job: turn a preclinical biotech into a clinical-stage company.

What does the financing fund?

Alethio will deploy the capital to advance its lead programme, ATX-011, through completion of Phase 1/2a studies in essential thrombocythaemia (ET) and to Phase 3 readiness. Additional MPN programmes will move toward IND submission. ATX-011 is currently in IND-enabling studies.

Preclinical data for ATX-011 has been selected for oral presentation at the American Society of Hematology (ASH) 2026 Annual Meeting — an early credibility marker for a company that hasn't dosed a patient yet.

The bottom line: €80.46 million buys Alethio a shot at Phase 3 readiness for its first drug.

Why target G6B?

ATX-011 is a first-in-class monoclonal antibody targeting G6B, a novel MPN target. According to the company, G6B is uniquely expressed on MPN-initiating stem cells but not on healthy stem cells. It is also expressed on megakaryocytes and platelets — the cells that drive thrombosis and transformation to myelofibrosis.

Alethio says these findings support ATX-011's potential to deliver broad therapeutic benefit across MPN patients, regardless of driver mutation.

Myeloproliferative neoplasms, including ET, are blood cancers marked by uncontrolled blood cell production and elevated risk of thrombosis, bone marrow scarring (myelofibrosis), and transformation to acute leukaemia.

The target's selectivity is the whole thesis: hit diseased stem cells, spare healthy ones.

What's wrong with current treatment?

Plenty, by the company's account. Current ET therapies are non-targeted treatments that have been around for decades — hydroxycarbamide and interferon — and they can affect, and disproportionately damage, healthy cells.

Dr. Rohit Batta, Chief Executive Officer of Alethio Therapeutics, described the patient journey bluntly: "Too often, a patient's first encounter with ET is a thrombotic event that lands them in the emergency room. What follows is typically lifelong treatment with therapies that can cause burdensome side effects and are associated with high rates of resistance."

He added: "Alethio was founded on a simple conviction – if you can selectively eliminate the cells driving disease, you can redefine what is possible for patients. This financing enables us to turn that conviction into reality."

The pitch is disease modification, not symptom control.

Who built the company?

Alethio was founded in 2021 as a University of Oxford spin-out by Professors Adam Mead and Beth Psaila, two globally recognised physician-scientists in MPNs. The company is based in Abingdon-on-Thames.

"Alethio Therapeutics was born from years of research at the University of Oxford and from our direct experience treating patients with MPNs. We founded the company to ensure that deep human disease insight and rigorous science translate into medicines that can alter disease progression, not just manage its symptoms," Mead and Psaila said on the company website.

Seghezzi framed the investment thesis around challenging orthodoxy: "The most transformative companies are built around insights that challenge long-held assumptions in medicine. In MPNs, the field has long accepted that controlling the disease is enough. Alethio challenges that assumption. By targeting the cells that drive the disease, its approach has the potential to move patients beyond symptom management toward true disease modification."

What comes after ATX-011?

Alethio has built ARTEMIS — Advanced Research & Translational Engine for Myeloproliferative Neoplasms — an integrated discovery and development engine designed to systematically identify, validate, and de-risk novel mutant disease drivers and therapeutic candidates against them.

Powered by ARTEMIS, the company is developing a second programme targeting mutant calreticulin (CALR)-driven disease, which occurs in roughly 30% of MPN patients.

Sally Dewhurst, Principal at Oxford Science Enterprises, said the team has built "not only a promising lead programme but also the ARTEMIS discovery platform, providing a powerful engine for future pipeline innovation."

With cash through Phase 3 readiness and an ASH 2026 oral slot on the calendar, Alethio's next milestone is its first human data.