Alethio Therapeutics, a biopharmaceutical company developing therapies for myeloproliferative neoplasms (MPNs), has raised £67 million in an oversubscribed Series A round. Sofinnova Partners and RA Capital co-led the round as new investors, alongside founding investor Oxford Science Enterprises, with support from Cancer Research Horizons and the University of Oxford.
MPNs are blood cancers characterised by the uncontrolled production of blood cells and an increased risk of thrombosis, bone marrow scarring (myelofibrosis) and transformation to acute leukaemia. Alethio is developing targeted therapies designed to selectively eliminate the disease-driving cells that sustain MPNs, to modify the underlying disease features, restore healthy blood counts and reduce thrombotic risk. Current therapies for essential thrombocythaemia (ET), such as hydroxycarbamide and interferon, are non-targeted treatments that have been around for decades and can affect, and disproportionately damage, healthy cells.
Its lead programme, ATX-011, is a monoclonal antibody that targets G6B, a protein expressed on platelets and megakaryocytes. ATX-011 is designed to normalise platelet counts in patients with ET by selectively enhancing platelet clearance. G6B is also expressed on MPN-initiating stem cells but not on healthy stem cells, and on megakaryocytes implicated in the development of bone marrow fibrosis. Preclinical data for ATX-011 has been selected for oral presentation at the American Society of Hematology (ASH) 2026 Annual Meeting, and Alethio is advancing the antibody through IND-enabling studies and toward clinical development in ET.
Alethio is a spin-out from the University of Oxford, founded by Adam Mead and Beth Psaila. The financing will enable the company to become clinical-stage, with capital deployed to take ATX-011 through completion of Phase 1/2a studies in ET, up to Phase 3 readiness, while also progressing additional MPN programmes towards IND submission. Graziano Seghezzi, Managing Partner at Sofinnova Partners, and Maxwell DeNies of RA Capital have been appointed to Alethio's board of directors.
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. 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 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. All of this is based on an exceptional team and founders with a deep understanding of the disease.
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.
Since its formation, Alethio has made incredible progress in translating pioneering University of Oxford science into a focused and ambitious biotechnology company. The team has built not only a promising lead programme but also the ARTEMIS discovery platform, providing a powerful engine for future pipeline innovation. We are proud to continue supporting the company and are delighted to welcome such an experienced syndicate to help Alethio transition to the next stage of growth; delivering meaningful impact for patients in the clinic.
