Alethio Closes $90 Million Series A Round
The oversubscribed round will advance the mutation-agnostic antibody ATX-011 toward clinical studies in essential thrombocythaemia.
Updated on Nov. 5, 2026 in Biotech
Alethio Therapeutics has closed an oversubscribed $90 million series A funding round. The Oxford spinout will use the proceeds to advance ATX-011 into Phase I/IIa studies in essential thrombocythaemia.
Why it matters
The financing moves a targeted antibody for a myeloproliferative neoplasm closer to the clinic, offering a possible alternative to non-targeted treatments that can damage healthy cells. Investor interest signals confidence in a platform approach to MPN drug discovery.
The disclosed figure is a $90 million series A round, described by the company as oversubscribed. The extraction provides no clinical efficacy data or valuation, so the scientific case for ATX-011 remains unverified.
The players
Alethio Therapeutics
A biotechnology company spun out from the University of Oxford that is developing targeted therapies for myeloproliferative neoplasms.
Sofinnova Partners
A European venture capital firm focused on life sciences that co-led the financing.
RA Capital
A healthcare-focused investment firm that co-led the financing.
Oxford Science Enterprises
A University of Oxford-linked investor that participated as a founding investor in Alethio.
The details
The round was co-led by Sofinnova Partners and RA Capital, with Oxford Science Enterprises participating as a founding investor alongside Cancer Research Horizons and the University of Oxford. ATX-011 is built on Alethio's ARTEMIS target-discovery engine and aims to normalise platelet counts by enhancing platelet clearance through G6B binding.
Timeline
October (prior year): Alethio emerged from stealth.
November 5, 2026: Alethio announced the $90 million series A close.
First half of 2028: Dosing in essential thrombocythaemia studies is expected to begin.
Big Picture
Unlike broadly acting kinase inhibitors such as ruxolitinib, ATX-011 is designed as a mutation-agnostic antibody that works through platelet clearance rather than JAK signalling. Its success would show whether targeted biologics can complement or replace non-selective therapies in essential thrombocythaemia.
For people living with essential thrombocythaemia, a therapy that targets the disease rather than broadly suppressing blood cells could mean fewer damaging side effects if it reaches the clinic. Patients and clinicians should note that the treatment remains years from availability and has not yet been tested in humans.
The takeaway
Targeted approaches to blood disorders could reduce collateral damage to healthy cells compared with current non-selective treatments. Readers should watch whether ATX-011 demonstrates clinical benefit as it enters human studies.
What happens next
Dosing in the essential thrombocythaemia studies is expected to commence in the first half of 2028.
Further reading
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