Viridian Therapeutics on Tuesday reported topline Phase 3 data for its rare autoimmune disease drug veligrotug as it aims to compete with Amgen and Horizon’s Tepezza.
Veligrotug hit on all primary and secondary endpoints in a 113-patient trial measuring its efficacy in thyroid eye disease, or TED, Viridian said Tuesday morning. After 15 weeks, the trial saw a 70% proptosis responder rate (PRR) in the active arm, compared to 5% in the placebo group (p<0.0001). The placebo-adjusted PRR came in at 64%.
The data ensure the program is on track for an FDA submission in the second half of 2025. Viridian is also conducting another Phase 3 trial in chronic TED, with both studies expected to make up the backbone of its FDA pitch.
Viridian’s stock $VRDN was up 15% in morning trading on Tuesday.
On an investor call Tuesday morning, Viridian CEO Steve Mahoney emphasized both the topline data and veligrotug’s administration profile. With similar efficacy and fewer infusions — veligrotug is given in five infusions compared to Tepezza’s eight — Mahoney said he believes Viridian has a winning commercial argument.
“Similar outcomes is what we’re seeing here — again, not a cross-trial comparison. You’ve got to draw that conclusion for yourself,” Mahoney said. “But when you see those profiles lined up against each other, we think we’re going to win that conversation every time.”
Mahoney also addressed questions about hearing impairment, a notable side effect for Tepezza and veligrotug’s class of drugs. Viridian reported a 5.5% placebo-adjusted rate of hearing impairment — 16% of patients had impairment in the active arm and 10.5% did so in the placebo arm.
The CEO pointed to Phase 4 results from Amgen and Horizon that showed a 10% placebo-adjusted rate (10% active, 0% placebo), in addition to a 12% rate in the chronic setting (22% active, 10% placebo). Mahoney said he expects Viridian’s chronic setting study to see a similar placebo-adjusted rate as the one reported Tuesday.
In a note last week, Leerink analyst Thomas Smith outlined expectations for how Viridian’s drug might measure up to Tepezza. Results for veligrotug (previously known as VRDN-001) appeared to fall in Smith’s “base case” scenario, being “generally competitive and consistent” with Tepezza data.
But Smith also noted that the Tepezza Phase 3 study, measured out to 24 weeks instead of 15, saw an 83% absolute PRR and 73% placebo-adjusted PRR.
Smith followed up with a new note, saying the data Tuesday helped Viridian’s case for another program that is designed to treat TED through subcutaneous injections called VRDN-003. Data from two Phase 3 trials are expected in the first half of 2026.
Editor’s note: This story has been updated with additional information from Viridian’s investor call Tuesday morning.