WALTHAM, Mass. — Viridian Therapeutics said its experimental thyroid eye disease treatment met the main goal of a late-stage clinical trial in patients with chronic disease, supporting the company’s plan to seek U.S. approval for the drug in early 2027.
The Waltham-based biotechnology company said elegrobart, a subcutaneous monoclonal antibody targeting the insulin-like growth factor-1 receptor, showed statistically significant improvement compared with placebo in the Phase 3 REVEAL-2 trial. The study evaluated dosing every four weeks and every eight weeks in 204 patients with chronic thyroid eye disease.
Viridian said the trial met its primary endpoint, with proptosis responder rates of 50% for patients receiving elegrobart every four weeks and 54% for those receiving the drug every eight weeks, compared with 15% for placebo. Proptosis, or eye bulging, is a key symptom of thyroid eye disease.
The company also reported statistically significant results on several secondary measures. Patients receiving elegrobart every four weeks had a 61% diplopia responder rate at week 24, compared with 38% for placebo. The every-eight-weeks group had a 55% diplopia responder rate.
“We are excited by today’s positive REVEAL 2 results and view these data as a major step forward for the chronic TED patient population. Given the IV-like proptosis response and our plans to launch with an at-home autoinjector, we believe elegrobart can meaningfully attract chronic patients to seek treatment. Elegrobart’s unmatched simplicity and convenience could uniquely drive expansion of the large and underserved chronic TED market,” said Steve Mahoney, President and Chief Executive Officer of Viridian Therapeutics. “With our anticipated launch of veligrotug, which is a short IV infusion course, and two positive phase 3 REVEAL pivotal clinical trials supporting both Q4 weekly and Q8 weekly subcutaneous dosing for elegrobart, our portfolio has the potential to offer anti-IGF-1R efficacy and safety in convenient treatment regimens for TED patients with active or chronic disease.”
Viridian said elegrobart was generally well tolerated, with most adverse events described as mild and consistent with the anti-IGF-1R drug class. The company reported low rates of hearing impairment in both treatment groups and said 91% of elegrobart-treated patients completed the full course of treatment. No treatment-related serious adverse events were reported.
“Chronic TED remains a challenging condition. Many patients have been living with this disease for years or decades and would benefit from an effective and convenient treatment option,” said John Mandeville, MD, PhD, an oculoplastic surgeon at Ophthalmic Consultants of Boston and who is also a clinical associate at the Massachusetts General Hospital. “These REVEAL 2 results demonstrate the potential for elegrobart to provide meaningful improvement in the signs and symptoms of TED in as few as three doses. What’s more, a simple autoinjector that patients can use at home could be an attractive option for many patients living with chronic disease.”
REVEAL-2 is the second successful pivotal Phase 3 trial for elegrobart, following positive results from the REVEAL-1 study in active thyroid eye disease. Viridian said it remains on track to submit a Biologics License Application to the U.S. Food and Drug Administration in the first quarter of 2027.
The company is also advancing veligrotug, its lead thyroid eye disease program. Viridian said veligrotug has received Breakthrough Therapy Designation from the FDA and is under Priority Review, with a target action date of June 30, 2026.
