First At-Home Thyroid Eye Disease Shot Approved

The FDA approved satralizumab (Enspryng), the first and only at-home subcutaneous treatment option for adults with thyroid eye disease (TED), developer Roche announced on Thursday.

The first-in-class drug is a humanized monoclonal antibody designed to bind to both soluble and membrane-bound interleukin (IL)-6 receptors, inhibiting IL-6-mediated signaling, a key pathway involved in inflammation.

The approval was based on the phase III SatraGO-1 and SatraGO-2 studies, despite the former failing to meet its prespecified primary efficacy endpoint at week 24. The studies enrolled 258 patients across 19 countries.

In SatraGO-2, 52.9% of patients with active TED in the satralizumab group had a reduction of at least 2 mm in proptosis compared with 23.4% of those in the placebo group, while 60.7% versus 25.8% had a reduction in diplopia. Consistent results were achieved in the overall trial population, which included patients with both active and chronic TED.

“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,” said César A. Briceño, MD, of the Scheie Eye Institute at the University of Pennsylvania in Philadelphia, in a statement from the drugmaker.

Satralizumab “has the potential to meaningfully expand our therapeutic options for patients with thyroid eye disease,” he added.

Also known as Graves’ ophthalmopathy, TED is a rare and complex inflammatory autoimmune disease that commonly occurs in people with hyperthyroidism. Symptoms, such as redness, eye swelling, eyelid retraction, a constant stare, proptosis, diplopia, and pain, can be potentially blinding, debilitating, and disfiguring.

Two other non-surgical TED treatments are currently approved — teprotumumab (Tepezza) and veligrotug (Lumvoa) — but both are administered intravenously and target the insulin-like growth factor 1 receptor.

No new safety signals were identified in the SatraGO trials, said Roche, adding that satralizumab’s safety profile was consistent with its known profile in neuromyelitis optica spectrum disorder, for which it gained approval in 2020.

The most common adverse events included upper respiratory tract infections and increased alanine aminotransferase levels. Satralizumab is contraindicated in patients with active or untreated latent tuberculosis and active hepatitis B infection.

The prescribing information also warns of decreased neutrophil counts, elevated liver enzymes during treatment, and risk of infection. Hepatitis B, tuberculosis, and liver transaminase screenings are required before the first dose.

Satralizumab can be administered by the patient or a caregiver after receiving training from a healthcare provider. The first three doses are given at weeks 0, 2, and 4, followed by maintenance injections every 4 weeks.

The drug is also being studied in additional neurologic, autoimmune, and inflammatory diseases that may benefit from the inhibition of IL-6-mediated signaling, according to Roche.