Alethio Therapeutics has closed a $90 million Series A to advance a blood-cancer antibody it prioritized after primate studies showed reversible platelet reductions. The Oxford spinout announced the financing on November 5, with Sofinnova Partners and RA Capital co-leading, ahead of human trials expected in 2028.
The company plans to take ATX-011 through Phase 1/2a studies in essential thrombocythemia, a chronic blood cancer in which excess platelets increase the risk of clots and bleeding. It aims to prepare the drug for Phase 3 development and move other candidates toward applications for human testing.
Alethio emerged from stealth in October 2025 emphasizing antibodies carrying attached drug payloads. Chief executive Rohit Batta told European Biotechnology that reversible platelet reductions in primates led the team to prioritize ATX-011, an antibody without an attached payload.
ATX-011 targets G6B, a protein on platelets that Alethio says also marks cancer-driving stem cells while being absent from healthy blood stem cells. The company hopes this will allow treatment across different disease-driving mutations. European Biotechnology described a study in just two nonhuman primates: platelet counts fell 80% after 96 hours and recovered as the antibody cleared. Patient benefit remains unproven.
BioPharma Dive reported that human testing is expected in the first half of 2028. Alethio currently lists ATX-011 as undergoing the work needed to support regulatory applications to begin those studies.