Viridian’s elegrobart met Phase 3 endpoints in thyroid eye disease, showing strong proptosis and diplopia improvements with a convenient subcutaneous dosing regimen, supporting a planned FDA filing in 2027.
Written By: Mohamed Musharaf, BPharm
Reviewed By: Pharmacally Editorial Team
Viridian Therapeutics reported positive topline results from the Phase 3 REVEAL-1 trial evaluating elegrobart in patients with active thyroid eye disease (TED), meeting its primary endpoint with high statistical significance and reinforcing its potential as a convenient, subcutaneous treatment option.
Elegrobart is a half-life-extended monoclonal antibody targeting the insulin-like growth factor-1 receptor (IGF-1R), designed for subcutaneous administration via autoinjector. If approved, it could become the first self-administered therapy for TED, offering a clear alternative to currently available intravenous treatments.
Steve Mahoney President and Chief Executive Officer of Viridian Therapeutics highlighted that REVEAL-1 results position elegrobart as a potentially first subcutaneous, at-home TED therapy with strong efficacy, convenient dosing, and significant market opportunity versus existing IV treatments.
Robust Efficacy Across Primary and Key Secondary Endpoints
The REVEAL-1 trial (NCT06625411) enrolled 132 patients randomized equally to elegrobart every four weeks (Q4W), every eight weeks (Q8W), or placebo.
At Week 24, the Q4W regimen met the primary endpoint, achieving a proptosis responder rate (clinically meaningful reduction in eye protrusion) of 54% compared to 18% with placebo (p<0.0001). The Q8W arm showed similarly strong efficacy, with a 63% responder rate (p<0.0001).
Mean reductions in proptosis were clinically meaningful in both dosing arms, reaching −2.33 mm (Q4W) and −2.50 mm (Q8W), versus −0.81 mm with placebo (p<0.0001 for both). MRI-based assessments further supported these findings, confirming reductions in orbital protrusion.
Beyond proptosis, elegrobart demonstrated notable benefits in diplopia. In the Q4W arm, diplopia response rates (defined as at least a one-grade improvement in double vision severity) reached 71% versus 32% with placebo (p=0.0009), with complete resolution observed in 51% of patients (p=0.0013). The Q8W regimen also showed improvements, though results were more modest and not consistently statistically significant across all diplopia endpoints.
Clinical Activity Score (CAS), a composite measure of inflammation in TED, also improved. Reductions to a score of 0 or 1 were higher with elegrobart, particularly in the Q8W arm (69% vs 50%; p=0.03), while the Q4W arm showed a numerical but non-significant improvement.
Elegrobart was generally well tolerated, with most adverse events mild and consistent with the anti-IGF-1R class. Hearing-related events were infrequent, with low placebo-adjusted rates (11.3% in Q4W and 2.3% in Q8W), all limited to tinnitus without associated hearing loss.
Convenience and Differentiation
The study highlights elegrobart’s potential to shift the TED treatment landscape by enabling at-home administration with as few as three subcutaneous injections given once every eight weeks. This may expand patient access compared to existing intravenous therapies that require multiple clinic-based infusions.
Viridian expects results from the ongoing REVEAL-2 Phase 3 trial in chronic TED in Q2 2026 and plans to submit a Biologics License Application (BLA) to the U.S. FDA in Q1 2027.
In parallel, the company’s second TED candidate, veligrotug, is under FDA Priority Review with a PDUFA target action date of June 30, 2026. Viridian is building a commercial infrastructure to support both assets, positioning itself to offer multiple treatment options across the TED spectrum.
Thyroid eye disease (TED) is a rare autoimmune condition, often linked to Graves’ disease, where inflammation behind the eyes causes symptoms such as eye bulging (proptosis), double vision (diplopia), and swelling. It can impair vision and significantly affect quality of life, particularly during the active phase.
References
Viridian Therapeutics Announces Positive Topline Results from Elegrobart Phase 3 REVEAL‑1 Clinical Trial in Active Thyroid Eye Disease, 30 March 2026, https://investors.viridiantherapeutics.com/news/news-details/2026/Viridian-Therapeutics-Announces-Positive-Topline-Results-from-Elegrobart-Phase-3-REVEAL1-Clinical-Trial-in-Active-Thyroid-Eye-Disease/default.aspx
An Efficacy, Safety, and Tolerability Study of VRDN-003 in Participants with Active Thyroid Eye Disease (TED) (REVEAL-1), ClinicalTrials.gov ID NCT06625411, https://clinicaltrials.gov/study/NCT06625411
Mohamed Musharaf A is a Pharmacy graduate from Ariyur, Puducherry, with a strong interest in data analysis and its application in healthcare. He is particularly interested in using data-driven insights to support pharmacovigilance and medical writing, with a focus on understanding complex datasets and translating them into meaningful, actionable solutions. Known for his dedication to learning and attention to detail, he continuously works to strengthen his analytical and domain knowledge.