Ethyreal Bio emerges with $101M to challenge Amgen’s Tepezza in thyroid eye disease

Ethyreal Bio has exited stealth with $101 million in funding, joining other biotechs aiming to challenge Amgen’s Tepezza (teprotumumab), a treatment for thyroid eye disease (TED). The Series A/B raise was led by Atlas Venture, Medicxi Ventures, and Avoro Capital, among others. The Cambridge, Massachusetts–based company is advancing ETHY-001, a fully human anti-TSHR antibody, into a planned first-in-human trial this year for both TED and Graves’ disease. ETHY-001 is designed to be a potentially best‑in‑class therapy with increased potency and selectivity versus existing TSHR‑targeting antibodies.