– ETHY-001 demonstrated potent and durable TSHR target engagement from a single subcutaneous dose in healthy volunteers –
– Rapid, dose-dependent pharmacodynamic activity observed with a pharmacokinetic profile supportive of dosing every three months or longer –
– ETHY-001 was well tolerated, with no serious or severe adverse events –
– First reported clinical results support continued development in TED and GD, with first patient cohorts initiated –
– ETHY-001 has received FDA Fast Track designation for the treatment of TED –
CAMBRIDGE, Mass., Oct. 19, 2026 (GLOBE NEWSWIRE) -- Ethyreal Bio (“Ethyreal” or “the Company”), a biotechnology company developing precision therapies for thyroid diseases with high unmet need, today announced the achievement of proof of mechanism in Part A of its first-in-human Phase 1 clinical trial, evaluating ETHY-001 in healthy volunteers. Designed to block activation of the thyroid stimulating hormone receptor (TSHR), ETHY-001 demonstrated significant pharmacodynamic effects denoting potent and durable TSHR target engagement after a single subcutaneous dose. These results demonstrate ETHY-001’s potential as a novel therapeutic option for TED and GD, conditions caused by autoantibody-driven activation of TSHR. Based on these data, Ethyreal is advancing development of ETHY-001 for the treatment of TED and GD and has initiated the first patient cohorts.
“These strong results represent a significant milestone for Ethyreal Bio and provide the first clinical validation of our differentiated approach to treating TSHR-driven disease,” said Niranjan Kameswaran, Ph.D., Chief Executive Officer. “The clear target engagement, pharmacokinetic durability, and favorable tolerability reinforces ETHY-001’s best-in-class potential as we advance into patients. We believe ETHY-001 has the opportunity to treat TED and Graves’ with a single mechanism and patient-friendly dosing regimen, potentially transforming the therapeutic landscape.”
Key results from Part A of the Phase 1 study highlight the potential of ETHY-001’s differentiated clinical profile:
- Potent target engagement: Clear TSHR engagement was evidenced by consistent thyroid function test changes across healthy volunteer cohorts.
- Rapid onset of effect: ETHY-001 produced an early and pronounced pharmacodynamic response following a single dose.
- Extended half-life: Pharmacokinetic profile supports a dosing interval of every three months or longer.
- Convenient administration: Low-volume, subcutaneous drug delivery provides improved ease and access for patients.
- Safety: ETHY-001 was well-tolerated with no serious or severe adverse effects.
Taken together, ETHY-001 has the potential to enable durable disease control across the full spectrum of TED and GD patients. Ethyreal is rapidly advancing clinical development of ETHY-001 and has initiated patient cohorts of individuals with TED and underlying GD. ETHY-001 has received the U.S. Food and Drug Administration's Fast Track designation for the treatment of TED.
About Graves’ Disease and Thyroid Eye Disease
Graves’ disease (GD) is the most common cause of hyperthyroidism, affecting approximately 1–2% of the adult population. GD is driven by pathogenic autoantibodies that activate the thyroid stimulating hormone receptor (TSHR), leading to excess thyroid hormone production and significant systemic consequences, including cardiovascular, neurological, and metabolic complications. Approximately half of patients with GD develop thyroid eye disease (TED). Today, treatment options for GD are limited, do not address the underlying cause, are associated with high rates of relapse, and carry risks of serious side effects. Many patients eventually undergo permanent thyroid removal. Existing therapies do not treat or prevent TED.
Thyroid eye disease is a serious, disfiguring, and potentially vision-threatening manifestation of GD that arises when pathogenic autoantibody-mediated TSHR activation occurs within the orbit of the eye. Most patients with TED have coexisting hyperthyroidism due to GD. TED can cause inflammation, proptosis, pain, diplopia, and in severe cases, permanent vision loss. Treatment options are limited and may be associated with burdensome systemic side effects including hyperglycemia and risk of hearing loss, as well as risk of relapse.
There remains a significant unmet need for safe, effective, durable, and targeted therapies for GD and TED that can address the full spectrum of disease.
About Ethyreal Bio
Ethyreal Bio is a biotechnology company headquartered in Cambridge, Massachusetts, developing precision therapies for thyroid diseases with high unmet need. The company’s lead program, ETHY-001, is a monoclonal antibody antagonist of the thyroid stimulating hormone receptor (TSHR). ETHY-001 is designed to rapidly and comprehensively block autoantibody-mediated activation of TSHR, the shared pathogenic driver of GD and TED. ETHY-001 is formulated for patient-friendly subcutaneous administration and incorporates half-life extension technology to enable infrequent dosing. Ethyreal Bio is currently evaluating ETHY-001 in a Phase 1 clinical trial for individuals with TED and underlying GD. ETHY-001 has received the U.S. Food and Drug Administration's Fast Track designation for the treatment of TED.
For more information, please visit www.ethyrealbio.com and follow the Company on LinkedIn.
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