Tepezza Just Lost Its Monopoly. Here's What Dethroned It.
For six years, Tepezza was the only FDA-approved drug for thyroid eye disease, generating nearly $2 billion in annual sales with zero competition. Viridian Therapeutics just changed that with the approval of Lumvoa, and the monopoly's days are officially numbered.
For six years, if you had thyroid eye disease and wanted an FDA-approved drug, you had exactly one option. Tepezza. That was it. Take it or leave it.
Now there are two.
The FDA just approved Lumvoa (veligrotug-vvze), made by Viridian Therapeutics, for the treatment of thyroid eye disease (TED). It's the first real competitor to Amgen's blockbuster Tepezza, which has been printing nearly $2 billion a year with zero marketed competition. Viridian's stock popped about 6% in extended trading on the news, and analysts are lining up with Buy ratings and price targets as high as $43.
But the bigger story isn't about one company's stock price. It's about what happens when a monopoly cracks open.
The Disease That Rearranges Your Face
Thyroid eye disease sounds mild. It is not. TED is an autoimmune condition, most often tied to Graves' disease, where the immune system attacks the tissue behind the eyes. The result: your eyes literally push forward out of their sockets (a symptom called proptosis), you develop double vision (diplopia), and the pain and disfigurement can be devastating.
Think of it like inflammation that remodels the architecture of your eye socket. The muscles and fat behind your eyes swell, and the eyeball has nowhere to go but out.
About 20% to 30% of TED patients develop moderate-to-severe disease. For those people, life before Tepezza meant high-dose IV steroids, radiation therapy, and a parade of surgeries: first to decompress the orbit, then to fix the eye muscles, then to repair the eyelids. Multiple operations, sequenced over months or years, with no guarantee of a good outcome.
Tepezza changed that calculus when it launched in 2020. But being the only game in town has its downsides, for patients and the market alike.
Why One Drug Wasn't Enough
Tepezza works well. Nobody disputes that. But "well" and "perfectly" aren't the same word.
Some patients can't take Tepezza because of contraindications: poorly controlled diabetes, pregnancy risk, or concerns about hearing loss (a known side effect). Others struggle with access; the drug requires eight IV infusions given every three weeks, and the price tag is steep enough that insurance fights are common. Physician surveys from 2025 found that specialists still flagged unmet needs around earlier intervention, safety, and broader access.
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Perhaps the most telling stat: market penetration in the U.S. remains in the single-digit percentage of an estimated 100,000 TED patients. That means the vast majority of people who could benefit from targeted therapy simply aren't getting it.
A monopoly didn't just mean no competition for Amgen. It meant no alternatives for patients.
Enter Lumvoa: Same Target, Different Approach
Lumvoa and Tepezza both go after the same molecular target, a protein called the IGF-1 receptor (IGF-1R). This receptor sits on the surface of cells behind the eye and, when overactivated by the immune system, drives the swelling and tissue expansion that cause TED symptoms.
But Viridian argues its drug hits that target harder. In preclinical studies, Viridian described Lumvoa as a "full antagonist" of IGF-1R, meaning it blocks the receptor's activity more completely. Tepezza, by comparison, was characterized as an "incomplete" blocker in those same bench experiments. Whether that distinction translates into meaningful clinical differences is still an open question, but the trial data are encouraging.
The treatment course is also notably shorter. Lumvoa requires five IV infusions over 12 weeks, given once every three weeks. Compare that to Tepezza's eight infusions. Fewer trips to the infusion center is a tangible quality-of-life win.
And there's one label detail that could matter a lot commercially: Lumvoa is approved for TED regardless of disease activity or duration. That means it covers both active TED (where inflammation is ongoing) and chronic TED (where the damage has already been done but symptoms persist). Viridian calls it the first approved TED treatment with labeling that includes data for both populations.
The Data That Got It Across the Finish Line
Lumvoa's approval rested on two Phase III trials, THRIVE (in active TED) and THRIVE-2 (in chronic TED), which Viridian describes as the two largest completed Phase III programs in thyroid eye disease to date.
The results in active TED were striking. In the THRIVE trial, 70% of patients on Lumvoa saw a meaningful reduction in eye protrusion at 15 weeks, compared to just 5% on placebo. That's not a subtle difference; it's a canyon. Improvements showed up as early as three weeks after the first infusion.
Diplopia told a similar story. About 49% of treated patients saw their double vision completely resolve, versus 12% on placebo.
Chronic TED is traditionally harder to treat because the inflammation has quieted but the physical damage remains. Even so, THRIVE-2 showed a 56% proptosis response rate versus 8% on placebo. Complete diplopia resolution hit 32% versus 14%. Not as dramatic as the active-disease numbers, but for a population that was previously funneled toward surgery, these are meaningful results.
Durability matters too. At week 52, 70% of patients who initially responded maintained their improvement. That's the kind of staying power that builds physician confidence.
The Safety Trade-Offs
No drug is free of side effects, and Lumvoa is no exception. Its safety profile is broadly consistent with what you'd expect from an IGF-1R inhibitor, which means it shares some concerns with Tepezza.
Infusion-related reactions occurred in about 9% of patients. The label also flags hyperglycemia (high blood sugar), particularly in patients with pre-existing diabetes, possible worsening of inflammatory bowel disease, and hearing problems that may be permanent in some cases. Common side effects included muscle spasms, headache, fatigue, diarrhea, and high blood pressure.
None of this is wildly different from Tepezza's risk profile. The question for doctors will be whether the shorter treatment course and broader label give Lumvoa an edge in the risk-benefit calculation for individual patients.
A $1.9 Billion Market Gets Its First Real Fight
Tepezza generated $1.9 billion in sales in 2024. That's a staggering number for a drug in a relatively niche indication, and it speaks to both the severity of TED and the pricing power of a monopoly.
Viridian reportedly plans to price Lumvoa at parity with Tepezza on a course-of-therapy basis. That's a smart opening move: it avoids a price war while letting the clinical profile and shorter treatment duration do the selling.
Analysts seem to like what they see. H.C. Wainwright reiterated a Buy rating with a $22 price target. RBC raised its target to $34. Wedbush went even higher, lifting to $43 with an Outperform rating. The consensus across the Street sits around a Strong Buy with average targets in the high $30s, well above the stock's recent trading level near $19.40.
But approval and commercial success are very different things. Viridian now has to build a sales force, convince physicians to prescribe a new entrant, navigate insurance formularies, and execute on reimbursement. Those are non-trivial challenges for a company that has never launched a product before.
The Bigger Picture: A Crowded Race Is Forming
Lumvoa is the first challenger, but it won't be the last. The TED pipeline is filling up fast with multiple mechanisms of action and delivery formats.
Immunivant is developing an FcRn inhibitor, which works by reducing the pathogenic antibodies that drive Graves' disease and TED. Sling Therapeutics is working on linsitinib, an oral small molecule targeting the same IGF-1R pathway; if that works, it could eliminate the need for infusions entirely. Tourmaline Bio has pacibekitug, an anti-IL-6 antibody, in Phase 2b development for TED. Even Roche is exploring its IL-6 blocker satralizumab in TED.
And Viridian itself isn't done. The company has a second antibody, elegrobart, delivered subcutaneously rather than intravenously. Its Phase III REVEAL trials showed strong proptosis and diplopia results with a shot instead of an IV drip. If approved, it could give Viridian a one-two punch: an IV option for the infusion center and a subcutaneous option for greater convenience.
The TED treatment market is projected to grow at roughly 8% to 9% annually through the early 2030s. That growth, combined with the fact that most patients still aren't being treated, means this isn't necessarily a zero-sum game. A bigger pie could mean room for multiple winners.
What Happens Next
For patients, this is unambiguously good news. More options mean more leverage: against the disease, against access barriers, and against the simple bad luck of not responding to the first drug your doctor tries.
For Amgen, the Tepezza monopoly era is over. The company is pushing into international markets (Japan, Europe) and developing a subcutaneous formulation of its own to defend market share. But the comfortable days of being the only option on the shelf are gone.
For Viridian, the real test starts now. The FDA approval is the entrance exam. The commercial launch is the final.
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