Viridian Shares New 52-Week Phase III Trial Data for Active TED

New THRIVE trial data highlight long-term proptosis response with veligrotug in thyroid eye disease patients.

Fresh long-term data is showing that an experimental thyroid eye disease (TED) treatment might be in it for the long haul.

In newly released data from the Phase III THRIVE trial, Viridian’s (Massachusetts, United States) veligrotug maintained proptosis response in 70% of active thyroid eye disease patients through 52 weeks. 

Veligrotug, an investigational intravenously delivered anti-insulin-like growth factor-1 receptor (IGF-1R) antibody, previously met all primary and secondary endpoints across two Phase III trials. 

The new data adds to veligrotug’s momentum toward a planned 2025 Biologics License Applications (BLA) submission. The update comes as clinicians continue to seek longer-lasting, lower-burden therapies for TED, a rare, vision-threatening autoimmune condition that can cause proptosis, diplopia and functional impairment.

With Breakthrough Therapy Designation already secured, the long-term THRIVE results could help solidify veligrotug’s case as a high-efficacy, durable option for TED management moving into next year.

Long-term durability data from THRIVE

Viridian’s results from THRIVE Phase III, a pivotal TED clinical trial, showed sustained efficacy of veligrotug (VRDN-001) in patients with active thyroid eye disease (TED), a serious and potentially disfiguring autoimmune condition that affects an estimated 100,000 people in the United States.

At the one-year mark, 70% of patients who achieved a proptosis response by week 15 maintained that response through week 52. This supports growing interest in long-term efficacy in TED therapies.

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For clinicians tracking TED, that’s a number worth circling. The durability data offer an important marker of long-term control in a condition where relapse and tapering challenges can complicate treatment decisions. The proptosis response was defined as a ≥1 mm reduction from baseline with no deterioration in the fellow eye.

No new safety signals were reported in the 52-week analysis. These results build on earlier data showing rapid onset of effect and improvement in diplopia as early as week 6, with a consistent safety profile across treatment arms. These findings are crucial for a condition where sustained efficacy is key, reinforcing veligrotug’s potential as a leading treatment for TED.

Primary and secondary endpoints met across two pivotal trials

Veligrotug has now met all primary and secondary endpoints in both THRIVE and THRIVE-2—phase III trials evaluating the drug in active and chronic TED, respectively.¹ The trials enrolled a broad patient population, including those with more severe disease and longer symptom duration.

Key efficacy outcomes include:

• Rapid onset of proptosis response (as early as 6 weeks)
• Reduction or resolution of diplopia in a high percentage of patients
• Durable proptosis response through 52 weeks (70% maintenance)
• No new safety concerns reported across the dataset

This consistent performance across trial phases supports the potential utility of veligrotug in both early and established TED, offering a fresh contender in a field that hasn’t seen much disruption.

Regulatory momentum builds

On the heels of its THRIVE readout, veligrotug received Breakthrough Therapy Designation from the U.S. Food and Drug Administration. The designation was granted based on the drug’s early and sustained proptosis response, a key marker of effectiveness in autoimmune eye disease This was coupled with clinical improvement in diplopia—two of the most functionally and cosmetically disabling features of TED.

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The Breakthrough Therapy pathway is designed to expedite development and review for treatments that may offer substantial benefit over existing options. Viridian confirmed plans to submit a Biologics License Application (BLA) in the second half of 2025.

A commercial launch in the United States is anticipated in 2026, pending regulatory approval.

A competitive edge with fewer infusions, faster onset

Unlike some existing IGF-1R inhibitors on the market, veligrotug offers a differentiated dosing profile. The drug is delivered via intravenous infusion but requires fewer infusions overall and has demonstrated faster onset of action in clinical trials.

That means less chair time, fewer patient visits and potentially more optimism in both the waiting room and the boardroom.

These advantages could position veligrotug as a more convenient and potentially cost-effective option in the therapeutic landscape, where infusion burden and access logistics remain a barrier for many patients.

The company has also highlighted a shorter administration time per infusion, which could further streamline clinic operations and improve patient throughput.

What’s next for veligrotug?

As veligrotug moves toward regulatory submission, attention will turn to commercial readiness, market positioning and physician adoption. TED remains a niche indication with high unmet need, particularly for patients who do not respond to corticosteroids or require steroid-sparing alternatives.

Analysts are watching closely to see how veligrotug’s performance compares with other IGF-1R inhibitors—particularly in real-world settings where durability, access and patient experience all factor into treatment choice.

Further real-world studies and health economic analyses are expected to follow the BLA submission, along with expanded access programs and potential ex-U.S. regulatory filings. If approved, veligrotug may help redefine standards in thyroid eye disease treatment, offering faster relief with fewer infusions. For now, veligrotug has earned its spot on the TED treatment radar and all eyes are on the 2026 launch window.

Editor’s Note: See the full press release from Viridian Therapeutics here.

Reference

1. Viridian Therapeutics, Inc. An efficacy, safety, and tolerability study of veligrotug (VRDN-001) in participants with chronic thyroid eye disease (TED) (THRIVE-2). ClinicalTrials.gov. 2025. Available from: https://clinicaltrials.gov/study/NCT06021054 Accessed May 22, 2025.