Alethio Therapeutics, an Oxford spinout, raised $90 million in an oversubscribed Series A to advance ATX-011 into Phase I/IIa studies for essential thrombocythemia (ET). The monoclonal antibody targets G6B on platelets and megakaryocytes, and the company argues the biology could support broader myeloproliferative neoplasm (MPN) relevance. Alethio said ATX-011 was designed to lower platelet counts by boosting platelet clearance, aiming to improve on hydroxyurea’s limitations in response rate, time to effect, and tolerability. The company’s Phase I/IIa plan is expected to generate first-in-patient data while progressing IND-enabling activities. The financing underscores investor appetite for mutation-agnostic approaches in rare blood disorders, especially when standard therapies remain non-targeted and delivered on broad hematologic endpoints. Strategically, the raise also signals a sustained emphasis on early clinical proof to establish target engagement, biomarker alignment, and downstream safety/tolerability before expanding into wider MPN labels.