> ## Content Index > Fetch the complete content index at: https://nexi.fund/llms.txt > Use this file to discover other available public pages before exploring further. # A $1.9 Billion Drug, Nine Delivery Bets, and an FDA Decision Due October 15 - URL: https://nexi.fund/thyroid-eye-delivery-race-2026/ - Published: 2026-10-08T18:00:10.000Z - Updated: 2026-10-08T18:00:10.000Z - Description: Amgen's Tepezza lost its only-drug status in June. Since then every thyroid-eye differentiation claim has collided with a larger company that moved first — and Roche's Enspryng decision lands October 15. - Author: Nexi.fund Labs - Tags: Biotech & Health, #mode-6, #hook-thesis, #track-A, #layout-thesis-spine The constraint in thyroid eye disease was never efficacy. Amgen's Tepezza works. It also asks patients for eight intravenous infusions across 24 weeks. Net sales still fell 10% in 2024, to $1.9 billion, on a lower net selling price rather than on falling patient numbers. Nine clinical programmes across five companies are now aimed at that gap. Almost all of them are chasing the same thing: a version of the drug a patient can take without sitting in an infusion chair. The companies clearing the FDA first are not the ones that raised the most money in 2026. 🎯 Tepezza stopped being the only approved drug for thyroid eye disease on 26 June 2026, when the FDA cleared Viridian's Lumvoa. The competitive axis is route of administration, not mechanism. On that axis Amgen is the fastest mover, not the target. The two big 2026 stealth rounds, Ethyreal's $101 million and Khartis's $95 million, are each differentiating against a larger company already further along on the same target and the same route. Thyroid eye disease, or TED, affects roughly 155 people per 100,000\. It is progressive and sometimes sight-threatening, and it attacks the tissue behind the eye rather than the thyroid itself. $1.9B TEPEZZA net sales, 2024 ↓ 10% vs 2023 #### Four years from launch to a plateau Net sales ran $0.4 billion in 2020, $1.66 billion in 2021 and $1.97 billion in 2022, then stalled at $1.9 billion in both 2023 and 2024\. Amgen attributes the 2024 decline to a lower net selling price, with volumes roughly flat. *Amgen, 2025* ## The infusion chair is the product Tepezza, or teprotumumab, was approved on 21 January 2020 and became the first and only therapy specifically indicated for TED. Horizon Therapeutics built it into a franchise and Amgen bought the company for $27.8 billion, closing on 6 October 2023\. The clinical result is real. In the pivotal programme, patients on teprotumumab reduced proptosis by an average of 2 mm by week 6, against 0.38 mm on placebo, and seven in ten reported improvement in double vision. The delivery is the problem. A course is eight infusions over 24 weeks, and Amgen has treated more than 25,000 patients worldwide on that schedule. The drug is a fully human monoclonal antibody against insulin-like growth factor 1 receptor, or IGF-1R. It has to be given in a clinic because it is both a biologic and an infusion. That combination is what caps the franchise. Tepezza's own commercial record reads like a product whose demand is limited by its format. Sales climbed from $0.4 billion in a partial 2020 to $1.97 billion in 2022\. Then they stopped. Full-year 2024 revenue came in at $1.9 billion, down 10%, and Amgen attributed the decline to the net selling price rather than to patient numbers. The company said in early 2025 that it expected continued price declines with relatively flat volumes. The 2026 quarters show what happens when a franchise is squeezed between price and format. First-quarter sales rose 29% to $490 million, but Amgen credited 22 percentage points of that to higher inventory. Second-quarter sales rose 14% to $576 million, with 6% from price and 6% from volume. Those are not the growth numbers of an unconstrained market leader. They are the numbers of a drug defending a position it reached six years ago. ## Amgen answered its own product first The most important competitive fact about TED in 2026 is that the incumbent moved first on delivery. On 6 April 2026, Amgen reported positive topline results from a Phase 3 trial of teprotumumab given subcutaneously through an on-body injector, a device the patient wears rather than a chair they sit in. The trial is registered as NCT06248619. The numbers were strong. The TEPEZZA OBI study hit a 76.7% proptosis response rate over the 24-week placebo-controlled period, against 19.6% on placebo, a difference significant at p<0.0001\. Mean proptosis reduction, a key secondary endpoint, was 3.17 mm at week 24 versus 0.80 mm on placebo. Safety was generally consistent with the intravenous formulation, with mild-to-moderate injection site reactions that did not interrupt or stop treatment. Read that against the franchise's own history and the logic is blunt. Amgen did not wait for a startup to solve the infusion problem. It solved it itself, and it now has a subcutaneous route that could carry the same brand, the same label, and the same commercial infrastructure. A separate Phase 3b/4 study for the FDA postmarketing requirement has also completed, testing four, eight and 16 intravenous infusions to assess retreatment. ## Roche is third to a slot it is calling first Roche, through Genentech, has the nearest dated catalyst. On 30 June 2026 the FDA accepted and granted priority review to a supplemental Biologics License Application for Enspryng, or satralizumab, in TED. The agency is expected to decide by 15 October 2026\. The Roche release describes Enspryng as the first and only at-home subcutaneous treatment option for the disease. The mechanism is different from the IGF-1R antibodies. Satralizumab is a humanised monoclonal antibody against the interleukin-6 receptor, given subcutaneously. It is not a new molecule. It has been approved for neuromyelitis optica spectrum disorder since 2020 and is available in roughly 90 countries, with a safety record across more than 10,000 patients. Roche is extending a marketed biologic into a new indication, not building a company around a first approval. The efficacy case rests on two identically designed Phase 3 studies, SatraGO-1 and SatraGO-2\. In SatraGO-2, 53% of patients on Enspryng achieved a proptosis response at week 24, against 23% on placebo. The company also reports reductions in clinical activity score for 78% to 90% of patients with active TED. > By targeting the underlying disease biology with a novel mechanism of action, this subcutaneous therapy has the potential to introduce a new treatment approach that combines clinical efficacy and a favourable safety profile with the convenience of at-home administration.— Levi Garraway, chief medical officer and head of global product development, Roche That is a credible claim. It is also not an exclusive one. As we wrote in July, when the FDA cleared Viridian's Lumvoa, the competitive set in this indication was already widening. Enspryng would be arriving into a market where a subcutaneous competitor is only one filing behind it. ## Two 2026 rounds bought the weakest seats The two venture rounds that drew attention this year are the furthest from the market, and each is differentiating against a company that got to the same place sooner. Ethyreal Bio emerged from stealth on 10 June 2026 with $101 million to develop ETHY-001, a half-life-extended monoclonal antibody against thyroid stimulating hormone receptor, or TSHR. The Series A was co-led by Atlas Venture and Medicxi, with the Series B led by Avoro. It is designed for subcutaneous administration through an autoinjector, with first-in-human trials planned for the second half of 2026\. The pitch is that blocking TSHR addresses the causal driver shared by TED and Graves' disease, rather than a downstream target. Viridian has the same idea on a faster clock. The company is developing a half-life-extended anti-TSHR monoclonal antibody for subcutaneous delivery in an autoinjector, for both TED and Graves' disease, and expects to file an Investigational New Drug application in the fourth quarter of 2026\. Ethyreal raised a $101 million Series A and B to reach a first-in-human study in the same half-year in which a company with an approved TED drug files the same class of molecule. Khartis Therapeutics has a comparable problem. It came out of stealth on 13 August 2026 with $95 million for an oral, selective IGF-1R inhibitor, which its release calls the first designed specifically for TED. The target is validated. But it is not novel, and the oral version already exists. Linsitinib is an oral IGF-1R inhibitor. Sling Therapeutics raised $123 million in a Series C on 16 September 2026, led by Forbion, and dosed the first patients in its global Phase 3 ORBIT trial the same day. When we covered Sling's round in September, the detail worth holding onto was that its oral programme is already in Phase 3 on a Fast Track designation, with a completed Phase 2b/3 behind it. It calls itself the first and only late-stage oral small-molecule therapy for TED. Two companies are claiming the same first, and one is years further along. ## Nine programmes, one axis Set the field out by route and the pattern stops looking like a race between startups and starts looking like a market being rebuilt around a device. Four programmes are already approved or in Phase 3\. Four are at the stage where the differentiation claim is doing more work than the data. | Company | Programme | Route | Stage | | ------------ | ----------------------- | --------------------------------------------- | --------------------------------------------- | | **Amgen** | Tepezza (teprotumumab) | IV infusion, 8 doses over 24 weeks | Approved 2020 | | **Amgen** | TEPEZZA OBI | Subcutaneous on-body injector | Phase 3 positive, April 2026 | | **Viridian** | Lumvoa (veligrotug) | Intravenous | Approved 26 June 2026 | | **Viridian** | Elegrobart (VRDN-003) | Subcutaneous autoinjector, every 4 or 8 weeks | Phase 3 positive, BLA planned Q1 2027 | | **Viridian** | Anti-TSHR antibody | Subcutaneous autoinjector | IND planned Q4 2026 | | **Roche** | Enspryng (satralizumab) | Subcutaneous, every 4 weeks | Priority review, decision due 15 October 2026 | | **Sling** | Linsitinib | Oral, 150 mg twice daily | Phase 3 ORBIT started | | **Ethyreal** | ETHY-001 | Subcutaneous, half-life extended | First-in-human H2 2026 | | **Khartis** | Oral IGF-1R inhibitor | Oral | First trial planned Q1 2027 | Route and stage as disclosed by each company, 2026\. Proptosis response rates are not comparable across programmes: they come from different trials, populations and endpoints. ## What 15 October actually prices The Enspryng decision is the only dated event in the field, and it will be read well beyond Roche. An approval would put an at-home, every-four-weeks subcutaneous injection from an already-manufactured biologic onto the market before either 2026 startup reaches the clinic. That compresses the differentiation window that Ethyreal and Khartis are selling to their investors. A second relevant detail is what Enspryng does not do. Its proptosis response in SatraGO-2, 53% against 23% on placebo, is lower than the 76.7% Amgen reported for subcutaneous Tepezza. Different trials and different populations make a direct ranking misleading, and no head-to-head study exists. But the comparison sets the commercial question the field will argue about: whether a monthly injection with a modest response rate and an established safety record beats an on-body injector with a stronger response and a known class of side effects. Reimbursement will decide more of that than the curve. The third variable is price. Tepezza already showed that a TED drug can lose 10% of its revenue to net price while volumes sit flat. Add an approved intravenous competitor, an approved or near-approved subcutaneous competitor, and two oral programmes, and the negotiation moves to payers. Whichever route wins on convenience will be asked to justify a premium against an oral pill that arrives in 2027 or later. That is the trade the money in 2026 is really taking, and it is a bet on margin, not on biology. 📊 **Signals to track** The FDA decision on Enspryng, due 15 October 2026. Whether Amgen files a supplemental application for subcutaneous Tepezza, and when. Viridian's elegrobart BLA submission, guided to the first quarter of 2027. First-in-human data from Ethyreal's ETHY-001, planned for the second half of 2026. Tepezza's net-price trajectory in Amgen's quarterly results, which has mattered more than volume for two years. [ FDA grants Priority Review to Roche's Enspryng for thyroid eye disease Primary source for the 15 October 2026 decision date, the SatraGO Phase 3 programme and the at-home subcutaneous positioning. F. Hoffmann-La Roche ](https://www.roche.com/media/releases/med-cor-2026-06-30?ref=nexi.fund) Company primary source, dated 30 June 2026. [ Viridian's second-quarter 2026 results and TED portfolio update Confirms the 26 June 2026 approval and launch of Lumvoa, the positive REVEAL-1 and REVEAL-2 subcutaneous results, the Q1 2027 BLA plan and the anti-TSHR IND for Q4 2026. Viridian Therapeutics ](https://investors.viridiantherapeutics.com/news/news-details/2026/Viridian-Therapeutics-Highlights-Recent-Business-Progress-and-Reports-Second-Quarter-2026-Financial-Results?ref=nexi.fund) Investor release, 6 August 2026. [ Amgen's subcutaneous Tepezza Phase 3 meets its primary endpoint Source for the 76.7% proptosis response, the 3.17 mm reduction at week 24 and the more than 25,000 patients treated worldwide. Amgen ](https://www.amgen.com/newsroom/press-releases/2026/04/amgen-announces-positive-topline-phase-3-results-for-subcutaneous-tepezza-in-adults-living-with-moderate-to-severe-active-thyroid-eye-disease?ref=nexi.fund) Company primary source, dated 6 April 2026. [ Sling doses the first patients in its Phase 3 ORBIT trial of oral linsitinib Basis for comparing Khartis's oral IGF-1R claim against a programme already in Phase 3 on a Fast Track designation. Sling Therapeutics ](https://slingtx.com/2026/09/16/sling-therapeutics-announces-first-patients-dosed-in-global-phase-3-orbit-pivotal-trial-of-linsitinib-for-thyroid-eye-disease?ref=nexi.fund) Company primary source, dated 16 September 2026.