FDA approves subcutaneous Enspryng for TED

The FDA has approved Enspryng (satralizumab, Genentech) for thyroid eye disease (TED), making the drug the first subcutaneous, at-home treatment option for TED and the first interleukin (IL)-6 receptor inhibitor approved in the indication.

Prior to the approval, the FDA granted priority review to Genentech's supplemental Biologics License Application for satralizumab as treatment for TED, with a PDUFA target date of October 15, 2026.¹

Levi Garraway, MD, PhD, Roche’s chief medical officer and head of global product development, stated, “Today’s FDA approval of Enspryng provides an important new option for people with thyroid eye disease, who have long faced limited treatment choices. As the first subcutaneous treatment for this condition, Enspryng offers a positive safety and efficacy profile and the potential for at-home administration.”

Basis for the FDA approval

The approval was based on the phase 3 SatraGO program that was comprised of 2 global clinical studies, SatraGO-1 (NCT05987423) and SatraGO-2 (NCT06106828).

SatraGO-1 and -2 are identically designed, phase III, randomized, placebo-controlled, multicenter studies to determine the efficacy, durability, and tolerability of Enspryng for the treatment of adults with active, moderate-to-severe TED and chronic TED. The studies enrolled a total of 258 patients from 19 countries who were then randomized 1:1 to receive Enspryng or placebo. 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.

SatraGO-1 did not meet its pre-specified primary efficacy endpoint at week 24, however, SatraGO-2 achieved a “significant and clinically meaningful” difference in proptosis response (52.9% in the Enspryng group compared to 23.4% in the placebo group) and in diplopia reduction (60.7% in the Enspryng group compared to 25.8% in the placebo group) in the active TED population.

Experts weigh in

César A. Briceño, MD, clinical trial investigator and associate professor of ophthalmology at the Scheie Eye Institute, University of Pennsylvania, commented on the approval, saying, “I am confident that the proptosis efficacy data are reliable. Although the SatraGO studies produced differing statistical outcomes, the treatment effects were remarkably consistent across the trials, and the primary difference appeared to be the placebo response rates.”

“While the magnitude of proptosis improvement is less robust than what has been reported with currently available IGF-1R antagonists, the clinical benefit remains meaningful. When considered alongside the favorable safety and tolerability profile observed in these studies, satralizumab has the potential to become an important addition to our therapeutic armamentarium, particularly for patients with multiple medical comorbidities or those who may not be ideal candidates for existing therapies,” added Briceño.

According to Raymond Douglas, MD, PhD, an aesthetic and reconstructive oculoplastic surgeon in Beverly Hills, CA, IGF-1R therapies certainly create the gold standard or yardstick to measure all others. That being said, he believes that satralizumab may be worthwhile for some patients and circumstances.

“Blocking IL-6 appears most suited to inhibiting the inflammatory nature of the disease and will likely provide some relief to these patients,” said Douglas.

Briceño and Douglas each praised the subcutaneous, at-home treatment option available with Enspryng.

“A subcutaneous therapy with a favorable safety profile, such as satralizumab, could substantially improve access to care for patients who live far from infusion centers or have difficulty traveling for treatment. This is particularly important in TED, where diplopia and ocular discomfort can make driving and commuting challenging. The ability to administer treatment at home offers a meaningful convenience advantage over infusion-based therapies,” stated Briceño.

“The route of administration, ie, subcutaneous injection, opens up potential barriers to access,” according to Douglas. “It is still to be determined how to properly monitor patients in this setting. These medications carry risks that require monitoring.”

César A. Briceño, MD

Assistant Dean for Student Social and Professional Networks, Perelman School of Medicine at the University of Pennsylvania

(p) 215.573.6688

Reference

1. Gambuzza L. FDA grants priority review to satralizumab sBLA for thyroid eye disease. Ophthalmology Times. June 30, 2026. https://www.ophthalmologytimes.com/view/fda-grants-priority-review-satralizumab-sbla-thyroid-eye-disease

2. FDA approves Roche’s Enspryng, a first-in-class IL-6R inhibitor, as the first and only at-home subcutaneous treatment option for thyroid eye disease (TED). Published October 15, 2026. Accessed October 16, 2026. https://www.roche.com/media/releases/med-cor-2026-10-16