WALTHAM, Mass. — Viridian Therapeutics said Monday that its experimental drug elegrobart met the primary endpoint in a late-stage clinical trial for patients with active thyroid eye disease, delivering statistically significant improvements in eye bulging and double vision.
The company reported that the Phase 3 REVEAL-1 trial achieved its main goal of improving proptosis, or eye protrusion, with both dosing regimens of the drug outperforming placebo at 24 weeks. Patients receiving elegrobart every four weeks showed a 54% proptosis responder rate, while those treated every eight weeks reached 63%, compared with 18% for placebo.
Viridian also said 51% of patients receiving the drug every four weeks experienced complete resolution of diplopia, or double vision, versus 16% in the placebo group.
The therapy, a subcutaneous monoclonal antibody targeting the insulin-like growth factor-1 receptor, was generally well tolerated in both dosing groups, with low rates of hearing-related side effects, according to the company.
“We are excited to report these results from REVEAL-1, the largest pivotal clinical trial conducted in active TED to date, which position elegrobart as potentially the first ever subcutaneous autoinjector treatment for TED,” said Steve Mahoney, president and chief executive officer of Viridian Therapeutics. “REVEAL-1 met its primary endpoint with high statistical significance. Elegrobart treatment drove robust proptosis responses in a treatment regimen comprised of as few as three subcutaneous doses. Further, in the Q4W arm, we saw clinically meaningful diplopia responses and diplopia resolution. Currently, the only marketed treatment for TED requires eight intravenous infusions and, despite low market penetration, annualized in 2025 to approximately $2B in revenues. We believe there is a significant opportunity with subcutaneous elegrobart in TED, including the potential to expand the market as an at-home and self-administered treatment option, if approved.”
An independent expert also highlighted the potential benefits of the therapy’s convenience and effectiveness.
“Subcutaneous elegrobart showed rapid and clinically meaningful reductions in proptosis and diplopia in REVEAL-1 with a highly convenient, well-tolerated dosing profile,” said Prem Subramanian, M.D., Ph.D., professor of ophthalmology at Colorado University Anschutz and chief of neuro-ophthalmology at the Sue Anschutz-Rodgers Eye Center. “Patients are seeking more treatment choices for TED, and there remains a clear need for a more conveniently administered therapy. I am very encouraged to see the data for elegrobart and believe it has the potential to reach more TED patients than an intravenous therapy and to provide them with an attractive treatment option.”
Viridian said a second Phase 3 trial, REVEAL-2, evaluating elegrobart in chronic thyroid eye disease remains on track to report results in the second quarter of 2026. The company plans to submit a biologics license application for the drug in early 2027.
The company ended 2025 with $875 million in cash and said it expects its existing resources, along with potential milestone payments and future product revenue if approved, to fund operations through profitability.
