Shares of Viridian Therapeutics (NASDAQ:VRDN) dropped roughly 40% on Monday after the company disclosed topline data from the Phase 3 REVEAL-1 trial of elegrobart in active thyroid eye disease (TED), even though the trial met its primary endpoint.
The REVEAL-1 results showed a statistically robust treatment effect. At week 24, proptosis responder rates were 54% for the elegrobart every four weeks (Q4W) arm and 63% for the every eight weeks (Q8W) arm, versus 18% for placebo. In addition, the Q4W dosing arm reported complete resolution of diplopia in 51% of patients compared with 16% for placebo.
The trial randomized 132 patients equally across three arms - elegrobart Q4W, elegrobart Q8W, and placebo. The study achieved statistical significance for its primary endpoint of proptosis responder rate in the Q4W group, with a p-value below 0.0001. Mean change from baseline in proptosis measured -2.33 mm for the Q4W group and -2.50 mm for Q8W, compared with -0.81 mm for placebo.
On safety, elegrobart was described as generally well tolerated, with adverse events consistent with those expected for the anti-IGF-1R class. Reports of hearing impairment were limited in the treatment arms. The placebo-adjusted rates for hearing-related events were 11.3% for the Q4W arm and 2.3% for the Q8W arm. All hearing-related reports were tinnitus and were not associated with measurable reductions in hearing.
Viridian said it expects to submit a Biologics License Application (BLA) to the U.S. Food and Drug Administration for elegrobart in the first quarter of 2027. The company’s second pivotal Phase 3 trial, REVEAL-2, which is evaluating elegrobart in chronic TED patients, remains on schedule for a topline readout in the second quarter of 2026.
Financially, Viridian reported $875 million in cash at the end of the fourth quarter of 2025. The company also has another TED candidate, veligrotug, which is currently under Priority Review at the FDA and carries a PDUFA target action date of June 30, 2026.
Key takeaways
- REVEAL-1 met its primary endpoint with highly statistically significant proptosis responder rates for elegrobart Q4W and Q8W versus placebo.
- Clinically meaningful secondary outcomes included a 51% complete resolution of diplopia in the Q4W arm compared with 16% for placebo.
- Despite favorable efficacy and an acceptable tolerability profile, Viridian's stock fell about 40% on the day of the announcement.
Risks and uncertainties
- Market reaction to clinical data can diverge significantly from trial outcomes, affecting equity valuations in the biotech sector.
- Regulatory timelines remain future events - the company expects a BLA submission in Q1 2027 and the ongoing REVEAL-2 topline readout in Q2 2026, both of which carry execution risk for the biopharma and healthcare sectors.
- Safety signals, even if limited (for example, tinnitus reports), will be monitored through regulatory review and could influence labeling or uptake if further data emerge.
This report reflects the data and company statements released in the REVEAL-1 topline announcement and the financial figures provided for the fourth quarter of 2025.