A Viridian Therapeutics drug for thyroid eye disease now has FDA approvalmaking it just the second treatment for this inflammatory disorder and providing key competitive advantages over the Amgen product that was first.
The drug, Viridian’s first commercial product, will launch immediately, the Waltham, Massachusetts-based biotechnology company said in the approval announcement after Friday’s market close. Known in development as veligrotug, or veli for short, Viridian’s intravenous therapy will be marketed under the Lumvoa brand.
Thyroid eye disease, or PDD, is an autoimmune disease that causes inflammation around and behind the eyes. The disease causes eye pain and redness as well as visual impairment. The distinguishing feature of TED is exophthalmos, which is swelling of the eyes.
TED develops in two stages: an active phase characterized by inflammation that develops over months or even years, followed by a stable or chronic phase in which symptoms persist. The disease is associated with overexpression of insulin-like growth factor-1 (IGF-1), a growth hormone responsible for inflammation. Lumvoa is an antibody designed to bind to the IGF-1 receptor, blocking its signaling.
Viridian’s submission to the FDA for Lumvoa was based on two placebo-controlled phase 3 studies, one in the active phase and the other in the chronic phase. Results from both studies showed a statistically significant and clinically meaningful improvement in signs and symptoms of TED measured at week 15. A reduction in proptosis was observed as early as three weeks after the start of treatment.
The most common side effects reported in studies included muscle spasms, headache, and hearing loss that may become permanent. In clinical trials, 17% of participants who received the study drug developed hearing loss, compared to 6% of those who received a placebo. Lumvoa’s label advises clinicians to assess the patient’s hearing before, during, and after treatment with the drug.
Corticosteroids have been used off-label to reduce inflammation caused by TED. Until Lumvoa, the only approved TED therapy was Amgen’s Tepezza, a monoclonal antibody designed to bind to the IGF-1 receptor. Like Viridian’s drug, Tepezza also carries a risk of hearing loss, so the safety profile is similar. But Lumvoa’s advantage comes from a shorter dosage regimen. Viridian medication is administered as an intravenous infusion that takes 30 to 45 minutes. The dosage regimen is five infusions in total, three weeks apart. In contrast, Tepezza is administered as an intravenous infusion that takes 60 to 90 minutes, or eight infusions in total three weeks apart.
Tepezza was approved by the FDA in 2020which will become Horizon Therapeutics’ largest product. Amgen acquired Horizon for $28 billion in 2023. For 2025, Amgen reported Tepezza revenue of $1.9 billion, an increase of 3% from the previous year.
In a note sent to investors Friday evening, Leerink Partners analyst Thomas Smith said the Viridian drug’s advantages over Tepezza include its rapid onset of action, durability and lower dosage burden. Viridian is also developing a subcutaneous injectable version of its drug called elegrobart. Last month, the company reported preliminary results showing that this drug met the primary endpoint of its Phase 3 study, with four- and eight-week dosing showing comparable responses to the intravenously infused version. Viridian announced plans to file a biologics license application for elegrobart in the first quarter of 2027. If approved, the company plans to make this product available in a self-injection device that patients can use at home.
“Overall, we think [Viridian] “is well positioned to compete in the multi-billion dollar TED market, based on veli’s best-in-class profile that appears differentiated from Tepezza in terms of effectiveness, safety and convenience, as well as elegrobart’s competitive profile in active and chronic TED,” Smith said.
Amgen could still compete with an injectable TED drug that attacks the IGF-1 receptor. An ongoing phase 1/2 study is evaluating a subcutaneously injectable antibody designed to provide enhanced binding and blocking of its target as well as a longer half-life.
Viridian has scheduled a conference call Monday at 8 a.m. to discuss Lumvoa’s approval and the company’s commercialization plans. Smith said he expects the call to provide more details on the product’s pricing. He expects a price comparable to Tepezza, which has a list price of more than $18,000 per bottle.
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