Thyroid eye disease (TED), also called Graves’ ophthalmopathy or orbitopathy, is an autoimmune disorder that causes inflammation in the orbital and retroocular tissues. It generally occurs as a manifestation of Graves’ disease, a condition in which the immune system attacks the thyroid gland, commonly affecting the eyes and skin. Although TED is usually found in Graves’ hyperthyroidism patients, some patients may have autoimmune euthyroid or hypothyroid thyroiditis. TED is mostly a mild, non-progressive, and self-limiting disease; however, in rare cases it can progress to vision loss. The negative impact of TED on the social and psychological well-being of individuals is an established consequence of the disease.

Key Takeaways

• Thyroid eye disease (TED) is associated with thyroid disease, and most commonly occurs in Graves’ disease, where it is estimated to be present in ~40% of patients.
• Epidemiological data are limited for TED, but it is reported in the literature that annual incidence in the general population is 16 per 100,000 in women and three per 100,000 in men.
• Based on these rates, Datamonitor Healthcare estimates that in 2020, there were 384,000 incident cases of TED worldwide, and expects that number to increase to 438,000 incident cases by 2029.
• The only approved drug in the TED space is Horizon’s Tepezza, which targets insulin-like growth factor-1 receptor. It is currently available as an intravenous formulation.
• There are currently no pipeline candidates in Phase I–III clinical development for TED in the US. High-impact upcoming events for drugs in the TED space comprise topline results from Tepezza’s Chronic TED trial, as well as topline Phase I/II trial results for VRDN-001.
• The overall likelihood of approval of a Phase I ophthalmology-other asset is 19.2%, and the average probability a drug advances from Phase III is 57.1%. Drugs, on average, take 8.7 years from Phase I to approval, compared to 8.9 years in the overall ophthalmology space.
• The distribution of clinical trials across Phase I–IV indicates that the majority of trials for TED have been in the late phases of development, with 67% of trials in Phase III–IV, and 33% in Phase II.
• Horizon Therapeutics has the highest number of completed clinical trials for TED, with three trials.
• Horizon Therapeutics leads industry sponsors with the highest overall number of clinical trials for TED.