FDA Approves First At-Home Subcutaneous Thyroid Eye Disease Treatment

The FDA approved satralizumab-mwge (Enspryng; Genentech) on October 15, 2026, for adults with thyroid eye disease (TED) following a priority review designation, making it the first and only at-home subcutaneous option for this patient population.¹

Expanding Treatment Options for TED

TED is a progressive rare disease, affecting approximately 155 people out of every 100,000, most commonly in those with hyperthyroidism. Common symptoms include redness, eye swelling, eyelid retraction, bulging of one or both eyes, double vision, and pain.

Satralizumab is a first-in-class humanized monoclonal antibody that is designed to bind to both soluble and membrane-bound IL-6 receptors, inhibiting IL-6–mediated signaling, a key pathway involved in inflammation. Patients or caregivers can administer it at home following training from a health care provider.

“Until now, our community has had very limited choices,” Christine Gustafson, CEO of the TED Community Organization, said in a news release. “The approval of Enspryng represents a critical turning point through a convenient, targeted option.”

Satralizumab Shows Efficacy in Active TED in SatraGO-2

The approval is the second US indication for satralizumab, following its first, on August 17, 2020, for adults with anti-aquaporin-4 antibody–positive neuromyelitis optica spectrum disorder (NMOSD).² The most recent decision was based on data from the phase 3 SatraGO program, which included SatraGO-1 (NCT05987423) and SatraGO-2 (NCT06106828).¹ Full results from both trials were shared in October 2025 at the American Society of Ophthalmic Plastic and Reconstructive Surgery Fall Scientific Symposium.

The phase 3 trials are identically designed, randomized, placebo-controlled, multicenter studies evaluating the efficacy, durability, and tolerability of satralizumab in adults with active, moderate-to-severe TED and chronic TED. The primary end point was the proportion of participants with active, moderate-to-severe TED who achieved a reduction in proptosis of at least 2 mm in the study eye from baseline at week 24.

Across both trials, investigators enrolled 258 patients from 19 countries and randomized them 1:1 to receive satralizumab or placebo. Although SatraGO-1 did not meet the primary efficacy end point, the active TED population in SatraGO-2 achieved a significant and clinically meaningful difference in both proptosis response (52.9% vs 23.4% in the satralizumab vs placebo groups, respectively) and in diplopia reduction (60.7% vs 25.8%). Consistent results were achieved in the overall SatraGO-2 population, which included both active and chronic patients.

Regarding satralizumab’s safety profile, it was consistent with its known profile in NMOSD, meaning no new safety signals were identified in the SatraGO trials. As with other biologics, the drug carries a warning for increased infection risk, with other precautions including hypersensitivity reactions, elevated liver enzymes, and decreased neutrophil counts.² In addition, the most commonly observed adverse effects were nasopharyngitis, headache, upper respiratory tract infection, rash, joint pain, extremity pain, fatigue, nausea, and inflammation of the lining of the stomach.

“As a clinical trial investigator, I have seen firsthand the potential of targeted therapies such as Enspryng,” César A. Briceño, MD, clinical trial investigator and associate professor of ophthalmology at the Scheie Eye Institute, University of Pennsylvania, said in a news release.¹ “The availability of an effective subcutaneous treatment option could provide greater flexibility for both patients and physicians while reducing the logistical burden associated with infusion-based therapies. Enspryng has the potential to meaningfully expand our therapeutic options for patients with [TED].”

Looking ahead, satralizumab is being studied in additional neurological autoimmune and inflammatory diseases that may benefit from inhibition of IL-6–mediated signaling.

References

1. FDA approves Genentech’s Enspryng, a first-in-class IL-6R inhibitor, as the first and only at-home subcutaneous treatment option for thyroid eye disease (TED). News release. Genentech. October 15, 2026. Accessed October 19, 2026. https://www.gene.com/media/press-releases/15137/2026-10-15/fda-approves-genentechs-enspryng-a-first
2. AJMC staff. FDA approves third drug for NMOSD. AJMC. August 17, 2020. Accessed October 19, 2026. https://www.ajmc.com/view/fda-approves-third-drug-for-nmosd