FDA OKs Enspryng, first at-home injection for thyroid eye disease

On October 15, 2026, FDA approved Enspryng (satralizumab-mwge) for adults with thyroid eye disease (TED), regardless of disease activity or duration. Enspryng is the first approved subcutaneous treatment for TED and can be administered at home by patients or caregivers after training.

TED is an autoimmune disease that causes inflammation in tissues around the eyes, leading to proptosis, diplopia, pain, and swelling. The condition can affect daily activities and, in severe cases, threaten vision. Enspryng blocks the interleukin-6 receptor (IL-6R), targeting a pathway involved in inflammation. At-home administration may ease the logistical burden for patients who would otherwise need infusion visits.

The approval was supported by the phase 3 SatraGO-1 and SatraGO-2 trials. In SatraGO-2, 52.9% of patients with active, moderate-to-severe TED achieved at least a 2-mm reduction in proptosis at week 24, compared with 23.4% receiving placebo. Among patients with diplopia at baseline, 60.7% experienced improvement versus 25.8% with placebo.

Results were also favorable in the overall SatraGO-2 population, which included patients with chronic TED. However, the two trials did not uniformly demonstrate benefit on their primary outcome: SatraGO-1 did not meet its primary efficacy endpoint at week 24.

Treatment begins with loading injections at weeks 0, 2, and 4, followed by maintenance dosing every 4 weeks. The recommended dose is 120 mg for adults weighing 40 to 100 kg and 180 mg for those weighing more than 100 kg.

No new safety signals were identified in the trials. The most common adverse reactions in patients with TED were upper respiratory tract infection and increased ALT levels, each occurring in 5.3% of Enspryng-treated patients. Labeling includes warnings for serious infections, elevated liver enzymes, decreased neutrophil counts, and hypersensitivity reactions. Patients require hepatitis B and tuberculosis screening and liver enzyme assessment before treatment, with liver enzyme and neutrophil monitoring during therapy. Enspryng is contraindicated in patients with active hepatitis B, active or untreated latent tuberculosis, or known hypersensitivity to the drug or its ingredients.

“Treating thyroid eye disease requires balancing efficacy, safety, and the practical realities of long-term treatment,” said César A. Briceño, MD, a clinical trial investigator and associate professor of ophthalmology at the University of Pennsylvania’s Scheie Eye Institute. “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.”

Source: Genentech. (2026 Oct 15). 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)