Viridian Therapeutics reports 70% durability at one year in Phase 3 THRIVE trial for veligrotug in thyroid eye disease

Viridian Therapeutics, Inc. has announced compelling 52-week durability data for veligrotug, its lead intravenously delivered anti-IGF-1R antibody targeting thyroid eye disease (TED), a rare autoimmune condition. The new data, emerging from its pivotal Phase 3 THRIVE clinical trial, shows that 70% of proptosis responders at week 15 maintained their clinical response at week 52. This long-term follow-up strengthens earlier topline results and supports veligrotug’s potential market positioning as a future treatment-of-choice for both active and chronic TED patients.

The announcement follows veligrotug’s recent Breakthrough Therapy Designation (BTD) from the U.S. Food and Drug Administration (FDA), which confirms its eligibility for regulatory Priority Review. Viridian Therapeutics expects to submit its Biologics License Application (BLA) to the FDA in the second half of 2025, with U.S. commercialization targeted for 2026.

What Does the 52-Week Durability Data Reveal?

The THRIVE trial enrolled patients with active TED and administered five intravenous infusions of veligrotug or placebo over a 15-week period. The primary analysis occurred at week 15, while durability was evaluated through week 52. Of the patients who demonstrated a reduction in proptosis (a hallmark of TED involving forward eye displacement) at the 15-week mark, 70% sustained this improvement by the end of one year.

Proptosis response durability was defined rigorously: patients needed to maintain a ≥2 mm reduction in proptosis without a ≥2 mm worsening in the fellow eye. These results were measured by exophthalmometry, ensuring clinical consistency. Importantly, no new safety concerns emerged, and most of the adverse events noted earlier had resolved by week 52.

Viridian‘s President and CEO, Steve Mahoney, described these findings as reinforcing the “strong and consistently robust clinical profile” of veligrotug, stating that the durability, rapid onset of action, and safety signal collectively elevate the candidate’s potential as a market leader.

Why Is Thyroid Eye Disease (TED) So Challenging to Treat?

TED is a rare autoimmune inflammatory disorder associated with Graves’ disease. It causes inflammation and tissue expansion behind the eyes, leading to debilitating symptoms such as bulging eyes (proptosis), double vision (diplopia), eye pain, and vision loss in severe cases. Management has historically been difficult due to limited therapeutic options and the chronic, relapsing nature of the disease.

Until recently, treatment options were largely limited to corticosteroids, radiation, or orbital surgery, all of which come with considerable risks and inconsistent outcomes. The approval of targeted biologics in recent years, such as anti-IGF-1R therapies, marked a significant turning point. Veligrotug enters this therapeutic landscape with potential advantages in efficacy, infusion schedule, and long-term results.

How Does Veligrotug Compare to Existing TED Therapies?

Veligrotug distinguishes itself from current IGF-1R inhibitors with a shorter dosing schedule—just five infusions, each spaced three weeks apart. The drug also offers a quicker onset of effect and has now demonstrated sustained efficacy over 52 weeks without additional dosing. This durability may address concerns about relapse and retreatment, particularly in patients with aggressive or relapsing TED.

In addition to these logistical and clinical advantages, veligrotug’s tolerability and safety profile—validated through THRIVE and THRIVE-2 trials—are expected to play a key role in its regulatory journey. The drug’s differentiated profile may make it more appealing to patients and physicians alike, particularly in comparison to longer and more burdensome treatment regimens.

What Did the THRIVE-2 Trial Add to Veligrotug’s Profile?

While THRIVE evaluated veligrotug in active TED, its sister trial THRIVE-2 focused on patients with chronic TED. Chronic cases often involve persistent symptoms such as diplopia even after the initial inflammatory phase subsides. Veligrotug demonstrated statistically significant improvements in diplopia resolution, making THRIVE-2 the first global Phase 3 trial to achieve this milestone in chronic TED.

These results expand veligrotug’s potential market applicability across both phases of the disease and underscore its role as a potential foundational therapy in the management of TED. The combination of THRIVE and THRIVE-2 data constitutes the largest clinical program to date in TED, further enhancing its standing before regulatory authorities and potential payers.

How Is Viridian Preparing for Commercialization?

Viridian Therapeutics has been actively preparing for the commercial rollout of veligrotug, pending regulatory approval. The company is leveraging its protein engineering and antibody discovery expertise to streamline production and ensure scalable delivery for the U.S. market. It anticipates submitting the veligrotug BLA in the second half of 2025 and aims to launch the drug commercially in 2026.

Concurrently, the company is developing VRDN-003, a subcutaneous IGF-1R antibody therapy that may offer additional convenience for TED patients. Two Phase 3 trials—REVEAL-1 and REVEAL-2—are underway to evaluate this candidate in both active and chronic TED. Viridian believes that veligrotug’s strong performance may help pave the way for VRDN-003’s market acceptance, should it also prove successful.

What Is the Market Opportunity for IGF-1R Inhibitors in TED?

The U.S. market for IGF-1R inhibitors in TED reached approximately $2 billion in 2024, reflecting the unmet clinical need and willingness of payers to support biologics that offer durable and meaningful outcomes. With the Breakthrough Therapy Designation and promising durability data, veligrotug is positioned to capture a substantial share of this market.

Viridian’s strategy focuses on first establishing a stronghold in the intravenous segment of the TED market before introducing more patient-friendly subcutaneous versions. This two-tiered approach may offer lifecycle management advantages and better penetration across multiple TED patient subsets.

What Are the Broader Implications for Viridian’s Pipeline?

Beyond veligrotug and TED, Viridian is diversifying its development pipeline to include neonatal Fc receptor (FcRn) inhibitors. Its clinical-stage candidates, VRDN-006 and VRDN-008, are designed for autoimmune conditions and may follow a similar development path of focusing on validated targets with differentiated dosing or delivery profiles.

This platform strategy—targeting known mechanisms with novel engineering—enables Viridian to derisk its development portfolio while maximizing potential commercial upside in rare diseases. The company’s pipeline expansion complements its flagship TED franchise and reflects its ambition to grow into a broader rare disease biopharma player.

How Are Investors Responding to the Veligrotug Results?

Market sentiment has remained positive following the release of the THRIVE 52-week data. Investors and analysts view the data as a critical validation of veligrotug’s durability and commercial promise. The clarity around regulatory timelines and the potential for a 2026 launch contribute to forward-looking confidence in Viridian’s valuation.

With two complementary TED programs in late-stage development and a strong cash position as of its latest filings, Viridian is positioned for an inflection point in value creation over the next 12–24 months. Institutional attention will likely intensify as the BLA submission nears and more data from REVEAL-1 and REVEAL-2 becomes available.

What Comes Next for Veligrotug and Viridian?

Looking ahead, Viridian is expected to complete its BLA submission in the second half of 2025 and intensify commercial readiness activities through early 2026. Final FDA approval, if granted, could establish veligrotug as a first-line IV therapy for TED, offering both physicians and patients a streamlined, evidence-backed option.

Meanwhile, the ongoing evolution of the TED therapeutic landscape—with greater recognition of the importance of early intervention and disease-modifying treatments—places veligrotug at the center of clinical conversation. If successful, the program could not only redefine standards of care but also validate Viridian’s broader strategy in autoimmune disease therapeutics.