Alethio Therapeutics Raises $90M Series A for Blood Cancer Drugs

Alethio Therapeutics has raised $90 million (£67 million) in an oversubscribed Series A round to advance targeted treatments for blood cancers. Sofinnova Partners and RA Capital co-led the financing, with founding investor Oxford Science Enterprises, Cancer Research Horizons and the University of Oxford also participating.

The money funds clinical development of ATX-011, the company's lead candidate for essential thrombocythaemia (ET). Alethio plans to move the drug through Phase 1/2a studies and reach Phase 3 readiness, while pushing earlier programs toward Investigational New Drug submissions.

What makes the target different?

Alethio is a University of Oxford spinout founded by Professors Adam Mead and Beth Psaila, physician-scientists who specialize in the biology of myeloproliferative neoplasms (MPNs). These are chronic blood cancers marked by abnormal production of blood cells. Patients face serious complications, including thrombosis, bone marrow scarring and progression to acute leukemia.

ET itself is driven by excessive platelet production and carries a heightened risk of blood clots. Existing treatments usually manage blood cell counts rather than selectively eliminating the cells responsible for disease progression.

Alethio takes a different route. ATX-011 targets G6B, a protein expressed on platelets and megakaryocytes. The company reports that G6B also appears abnormally on certain disease-initiating stem cells linked to MPNs, while healthy stem cells do not express it in the same way. ATX-011 is designed to enhance platelet clearance and potentially attack the cells that sustain the disease, a mechanism Alethio believes could work across patients with different underlying genetic mutations.

CEO Dr. Rohit Batta framed the unmet need 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," Batta said. "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."

Why the investors wrote the checks

Graziano Seghezzi, Managing Partner at Sofinnova Partners, said the company challenges the field's basic assumption that controlling MPNs is enough.

"By targeting the cells that drive the disease, its approach has the potential to move patients beyond symptom management toward true disease modification," Seghezzi said.

Maxwell DeNies of RA Capital pointed to the science behind the pitch.

"We were drawn to the strength of the biology underpinning Alethio's approach. G6B is a highly differentiated target with compelling human data supporting its role in selectively identifying disease-driving cells in MPN. Combined with the extensive patient-derived validation generated by the team, this creates a strong scientific foundation for the programme as it advances toward the clinic," DeNies said.

Sally Dewurst, Principal at Oxford Science Enterprises, noted the company has translated Oxford research into both a lead program and the ARTEMIS discovery platform, which the financing also supports and which is intended to generate further targeted therapeutic candidates.

What happens next?

The science has already cleared some external hurdles. Alethio has advanced ATX-011 through preclinical development, and its research was selected for an oral presentation at the American Society of Hematology's 2026 Annual Meeting — a competitive slot that signals peer attention.

The round also reshaped governance. Seghezzi and DeNies joined Alethio's board following the close.

The $90 million now converts biology into data. Alethio must show in Phase 1/2a trials that clearing G6B-positive cells can change the disease course, not just the platelet count.