Viridian Therapeutics, Inc. reported positive topline data from its REVEAL-1 phase 3 clinical trial evaluating elegrobart for the treatment of thyroid eye disease (TED).
Take note: Elegrobart isn’t to be confused with the company’s other TED-indicated therapeutic, veligrotug.
That was going to be my first question …
Not surprising, considering veligrotug has been the subject of regulatory news as of late.
Case in point: The therapeutic is currently the subject of the FDA’s ongoing review of its Biologics License Application (BLA), which the company submitted in November 2025 and the federal agency accepted in late December 2025.
Alrighty then—let’s get a refresh on this second TED therapeutic.
You may be more familiar with its previous name: VRDN-003.
What it is: Similar to veli, elegrobart is an anti-insulin-like growth factor-1 receptor (IGF-1R) monoclonal antibody designed to:
- Block cell surface receptor activity
- Target antibody and protein engineering for specific diseases and autoimmune disorders (such as TED)
And how is it administered?
Eligrobart is delivered via a subcutaneous self-injection with a dosing regimen of every 4 (Q4W) or 8 (Q8W) weeks.
- See how this differs from veli.
Now let’s talk REVEAL-1.
REVEAL-1 (NCT06625411) is one of two randomized, double-masked, placebo-controlled phase 3 studies (the other being REVEAL-2) analyzing the safety and efficacy of eligrobart for active and chronic TED.
A rundown on its setup:
- 85 participants randomized in a 1:1:1 ratio
- Eligrobart arm (n = 44)
- Placebo arm (n = 44)
- Each patient received either eligrobart or a placebo Q4W or Q8W
- Initial loading dose: 600 mg (via two 300 mg injections)
- Following doses: 300 mg single injections
- Total doses: six (for Q4W) or three (for Q8W)
And the findings?
We’ll start with the most important: The study met its primary and key secondary endpoints (both measured with exophthalmometry) with “highly statistical significance.”
- The primary objective: Proptosis responder rate, as measured by achieving at least a 2 mm improvement in proptosis from baseline at week 24 (vs placebo).
- The secondary endpoint: Q4W proptosis mean change from baseline in the study eye.
- Others included change in and rate of clinical activity score (CAS) in the study eye, as well as diplopia responder and resolution rate with a baseline score > 0.
Give me some numbers.
For the primary endpoint: The proptosis responder rate (and mean change from baseline) for the Q4W-dosed patients was:
- 54% among elegrobart-treated patients (p < 0.0001)
- 18% among placebo-treated patients (p < 0.0001)
Talk more about the secondary endpoints for the Q4W dosing.
The proptosis mean change from baseline was:
- -2.33 mm among elegrobart-treated patients (p < 0.0001)
- -0.81 mm among placebo-treated patients (p < 0.0001)
As for the diplopia responder rate and diplopia complete resolution, respectively, this was achieved by:
- 71% and 51% of elegrobart-treated patients (p = 0.0009, p = 0.0013)
- 32% and 16% of placebo-treated patients (p = 0.0009, p = 0.0013)
And the percentage of patients achieving a CAS reduction to 0 or 1 was:
- 57% among elegrobart-treated patients (p = 0.24)
- 50% of placebo-treated patients (p = 0.24)
Let’s take a look at the Q8W dosing patients.
The diplopia responder rate and diplopia complete resolution, respectively, were achieved by:
- 54% and 28% of elegrobart-treated patients (p = 0.05, p = 0.014)
- 32% and 16% of placebo-treated patients (p = 0.05, p = 0.014)
And those who achieved a CAS reduction were:
- 69% among elegrobart-treated patients (p = 0.03)
- 50% of placebo-treated patients (p = 0.03)
Did we miss any others?
Just a couple of secondary endpoints (proptosis responder rate and mean change from baseline).
See here for those outcomes among both dosing groups.
Next up: safety outcomes.
In general, Viridian noted elegrobart as generally well-tolerated in each group, with the majority of its associated adverse events (AEs) reported as mild and “expected from the anti-IGF-1R class.”
Notably: Between both Q4W and Q8Q treatment arms, hearing impairment rates were low, and “all reports were of tinnitus, none of which were associated with reductions in hearing.”
- The numbers: 11.4% and 2.3% placebo-adjusted rates, respectively
What’s the potential big-picture significance?
Viridian President and CEO Steve Mahoney noted that elegrobart could become the “first ever subcutaneous autoinjector treatment for TED.”
So … with all of this data in mind … what’s next?
Excellent question. Elegrobart is reportedly on track for a potential BLA submission by early next year (Q1 2027).
And don’t think we forgot about that second phase 3 trial (REVEAL-2) evaluating chronic TED patients.
- The latest: Viridian expects to release a data readout of its topline data in Q2 2026 (April 1-June 30).
Nice! And just to bring this full circle: Any updates on that veligrotug BLA ?
No major updates since our last report: Its Prescription Drug User Fee Act (PDUFA) target action date is still set for June 30.