The US Food and Drug Administration (FDA) has approved Enspryng (satralizumab) for the treatment of adults with thyroid eye disease (TED).
TED is a chronic endocrine, autoimmune disease characterized by immune-mediated orbital inflammation that greatly impacts a person’s vision. The condition often occurs in people with hyperthyroidism or Graves’ disease, but also can occur in association with hypothyroidism, euthyroidism, and Hashimoto’s thyroiditis. Graves’ disease affects approximately 1% to 2% of the adult population, with an estimated 40% of patients subsequently developing TED over the course of their lifetime. The onset of TED typically occurs between 30 and 50 years of age, with the disease course more severe after the age of 50. Common symptoms can include ocular discomfort, upper eyelid retraction, dry eyes, tearing, inflammation, erythema, light sensitivity, and sensation of a foreign body present in the eye.
Satralizumab is a humanized monoclonal antibody designed to bind to both soluble and membrane-bound interleukin-6 receptors (IL-6R), inhibiting IL-6 mediated signalling involved in inflammation. The treatment is the first and only at-home subcutaneous treatment option for TED. Satralizumab was previously approved for neuromyelitis optica spectrum disorder (NMOSD) in 2020.
The approval is based on results from the pivotal phase 3 SatraGO-1 (NCT05987423) and SatraGO-2 clinical trials (NCT06106828). Both studies are identically designed, randomized, placebo-controlled, multicenter studies looking at the efficacy, durability, and tolerability of satralizumab in patients with active, moderate-to-severe and chronic TED.
The studies enrolled a total of 258 patients. The primary endpoints were the proportion of participants with active, moderate-to-severe TED who achieved an at least 2 mm reduction in proptosis in the study eye from baseline at week 24. While SatraGO-1 did not meet its primary efficacy endpoint at week 24, SatraGO-2 achieved significant and clinically meaningful difference in proptosis response (52.9% in the satralizumab group compared to 23.4% in the placebo group) and in diplopia reduction (60.7% in the satralizumab group compared to 25.8% in the placebo group) in the active TED population. Consistent results were achieved in the overall population, including both active and chronic patients, in SatraGO-2.
No new safety signals were identified in both trials, with a safety profile consistent with its known profile in neuromyelitis optica spectrum disorder (NMOSD).
Satralizumab is also being studied in additional neurological autoimmune and inflammatory diseases and has been accepted by the FDA for priority review in myelin oligodendrocyte glycoprotein antibody-associated disease (MOGAD).
For more information, visit: https://www.roche.com/media/releases/med-cor-2026-10-16
To learn more about TED and other rare endocrine disorders, visit https://checkrare.com/diseases/endocrine-disorders/
