On Oct 15, the FDA approved satralizumab-mwge (Enspryng; Genentech, a member of the Roche Group) for adults with thyroid eye disease (TED), clearing what the company calls the first and only at-home subcutaneous treatment for the condition. 

Satralizumab can be administered by the patient or a caregiver following training by a clinician, Roche said. 

The FDA approval for satralizumab in TED is based on data from the phase 3 SatraGO program (SatraGO-1 and SatraGO-2). According to the manufacturer, although SatraGO-1 did not meet a 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.

Satralizumab is a humanized monoclonal antibody designed to bind to interleukin-6 (IL-6) receptors and thus inhibit IL-6-mediated signaling, a known key pathway involved in inflammation. It was initially approved in 2020 for neuromyelitis optica spectrum disorder, a rare, serious neuroinflammatory disease.

Although TED is considered a rare condition — it is estimated to occur in 16 women and 3 men per 100,000 population — recent gains in immunology have fueled the expansion of drugs available for the disease, said Marius N. Stan, MD, an endocrinologist and the director of the TED Clinic at the Mayo Clinic in Rochester, Minnesota.

A 'Fortuitous Junction' of Interest and Ability

Stan noted a "fortuitous junction between the interest in this field in understanding the mechanism of disease, combined with our ability to develop drugs to target a specific element of the pathophysiological pathways."

"We can target the antibodies. We can target the receptors. We can target the immune cells that are creating these antibodies. I think there are efforts for multiple steps of the cascade of events that leads to thyroid eye disease," he told Medscape Medical News.

Teprotumumab (Tepezza, Amgen) was approved by the FDA in 2020 as the first drug cleared in the US for TED. Amgen also is working on a subcutaneous injection for this drug. Amgen told Medscape that, depending on insurance, some patients may receive teprotumumab intravenous (IV) infusions at home.

And in June 2026, the FDA approved veligrotug-vvze (Lumvoa, Viridian) for treatment of TED, based on results from the THRIVE studies. 

THRIVE was a well-executed, positive phase 3 trial that demonstrated that veligrotug produces "clinically meaningful improvements in inflammation, proptosis, diplopia, and quality of life in selected patients with active TED," wrote Zhenyang Zhao, MD, MS, and Vinay Kumar Aakalu, MD, MPH, in a commentary published in Ophthalmology.

Further research is needed to help clinicians weigh the options now available for TED, Zhao and Aakalu noted in their commentary. 

"However, future head-to-head and comparative effectiveness studies would help to establish its role among treatment options for TED," they added.

Another Roche drug, tocilizumab (Actemra, Genentech) has been used off label for TED. It was both effective and generally well tolerated in some moderate-to-severe cases, according to early results from a small, open-label, prospective study. 

These results "are consistent with previous reports on the use of [tocilizumab] in TED," Joanna Rymuza, MD, PhD, of the Medical University of Warsaw, Poland, and coauthors wrote. However, they noted, previous studies varied "substantially" in the patient population, route of administration, and dosage of medication given. 

Tocilizumab is one of the new therapies being studied broadly for immune-mediated inflammatory disease and is approved in more than 115 countries, with rheumatoid arthritis as a common indication. 

It has approvals for other conditions, including cytokine release syndrome associated with chimeric antigen receptor T-cell therapy and systemic juvenile idiopathic arthritis, and is already used as a treatment for certain cases of TED, although it is not approved for this indication. 

The current study was intended to expand options for patients whose TED persisted after treatment with the IV glucocorticoids (GCs), the standard first-line therapy for many years in the majority of patients with this condition.

Study Details

Rymuza and coauthors followed 32 patients seen at a clinic in Warsaw and 12 at a clinic in Belgrade, Serbia. All patients had active, moderate-to-severe, GC-resistant TED and received tocilizumab 8 mg/kg IV every 4 weeks for four cycles. 

The primary outcomes were positive composite ophthalmic response, that is, improvement in at least two features in the study eye without concurrent deterioration in the fellow eye, and improvement in disease-specific quality of life (QOL). 

The positive ophthalmic score was based on a decrease in eyelid aperture by ≥ 2 mm, a decrease in proptosis by ≥ 2 mm, an improvement in diplopia by ≥ 1 grade on the Gorman diplopia score, or a decrease of ≥ 2 points in the 7-item clinical activity score.

The researchers reported results at 24 weeks, because the majority of patients were going on to receive rehabilitative surgery. Overall, 20 of 32 patients (62.5%) in the Warsaw cohort and all 12 patients (100%) in the Belgrade cohort met the criteria for a positive composite ophthalmic response.

"As this was a composite response criterion rather than a numerical scale, it did not have a defined numerical range. The response was assessed individually for each patient," Rymuza told Medscape Medical News in an email.

The same percentage of patients in each cohort, 62.5% in Warsaw and 100% in Belgrade, recorded an improvement in the disease-specific QOL questionnaire.

Adverse Effects

"Patients are often concerned about the potential adverse effects of new biological therapies," said Rymuza, but the study provided reassuring data showing that tocilizumab was not only effective but also generally well tolerated.

Most adverse events were mild-to-moderate and resolved spontaneously; however, one patient developed unstable angina after the second dose and was withdrawn from the study. 

"This highlights the importance of appropriate patient selection and careful monitoring during treatment," Rymuza said. 

Although larger, randomized controlled trials are needed to fully assess the risks and benefits of tocilizumab in TED and to "determine its role among other biological agents," Rymuza and coauthors wrote, the results of their study provide "further convincing evidence" of a second-line role for this drug. 

Rymuza reported no relevant financial disclosures. Those reported by her coauthors include consulting fees from argenx, Ergomed CRO, and Lundbeck, and speaker fees and/or honoraria for advisory boards of Amgen, argenx, Berlin-Chemie, Lundbeck, and Merck, all outside the submitted work. 

Stan reported that Mayo Clinic has received support from Viridian, Immunovant, Amgen, and Ethyreal Bio. He also has received consultation fees from firms including Merida and Lundbeck. 

Zhao has reported receiving financial support from Research to Prevent Blindness and the National Institutes of Health (NIH). 

Aakalu has reported support from NIH, Eversight, Michigan Economic Development Council, Ono Pharmaceuticals, and other companies. 

Kerry Dooley Young is a freelance journalist based in Washington, DC. She has reported on the FDA for more than two decades.