06/29/2026 | Press release | Distributed by Public on 06/29/2026 23:24
Monday, Jun 29, 2026
FDA Grants Priority Review To Genentech's Application for Enspryng, the First and Only At-Home Subcutaneous Treatment Option for Thyroid Eye Disease (TED)
● The filing application is based on improvements seen across key efficacy endpoints from the global Phase III SatraGO-1 and SatraGO-2 studies, including proptosis (bulging eyes) and diplopia (double vision) in active TED
● Enspryng (satralizumab) has the potential to become the first at-home subcutaneous disease-modifying standard of care for TED
● TED is an autoimmune disease affecting approximately 155 out of every 100,000 people that can lead to facial disfigurement and vision-threatening complications if left untreated
South San Francisco, CA -- June 29, 2026 --
Genentech, a member of the Roche Group (SIX: RO, ROP; OTCQX: RHHBY), announced today that the U.S. Food and Drug Administration (FDA) has accepted and granted priority review to a supplemental Biologics License Application (sBLA) for Enspryng® (satralizumab) for the treatment of thyroid eye disease (TED). The filing acceptance is based on results from the two randomized, placebo-controlled global Phase III SatraGO studies assessing the safety and efficacy of Enspryng in patients with moderate to severe TED. The data were presented at the American Society of Ophthalmic Plastic and Reconstructive Surgery (ASOPRS) in October 2025. The FDA is expected to make a decision on approval by October 15, 2026.
"The FDA's decision to grant priority review to Enspryng is an important step toward expanding treatment options for people living with thyroid eye disease," said Levi Garraway, M.D., Ph.D., chief medical officer and head of Global Product Development. "By targeting the underlying disease biology with a novel mechanism of action, this subcutaneous therapy has the potential to introduce a new treatment approach that combines clinical efficacy and a favorable safety profile with the convenience of at-home administration."
The totality of data from the pivotal Phase III SatraGO program demonstrated that Enspryng provided consistent, clinically meaningful improvements across key TED signs and symptoms, with a favorable and differentiated safety profile compared to currently available treatments. For the primary endpoint of proptosis (bulging eyes) response at week 24, 53% of patients treated with Enspryng in SatraGO-2 achieved a proptosis reduction compared to 23% of patients treated with placebo, meeting statistical significance. Similarly, in the SatraGO-1 trial, 49% of patients achieved a proptosis response compared to 31% in the placebo arm. While this numerical improvement did not meet statistical significance, SatraGO-1 offers additional confirmatory evidence regarding the potential benefit of satralizumab in this setting. Enspryng also drove notable improvements in secondary measures across both studies, achieving reductions in clinical activity score (CAS) for 78% to 90% of patients with active TED and improving double vision (diplopia) for 44% to 61% of patients with active TED in SatraGO-1 and SatraGO-2 respectively.
No new safety signals were identified in the SatraGO trials, with Enspryng's safety profile consistent with its known profile in neuromyelitis optica spectrum disorder (NMOSD).
About SatraGO-1 and -2
SatraGO-1 (NCT05987423) and -2 (NCT06106828) 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 inactive TED. The studies enrolled a total of 258 patients from 19 countries. Participants were 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.
About thyroid eye disease (TED)
TED, also known as Graves' ophthalmopathy, is a complex inflammatory autoimmune disease, affecting the area around the eyes and the eyes themselves, that can be sight-threatening, debilitating and disfiguring. The most common symptoms are redness, swelling of the eyes, eyelid retraction, appearance of a stare, bulging of one or both eyes (proptosis), double vision (diplopia) and pain.
TED is a progressive rare disease that affects approximately 155 people out of every 100,000. It most commonly occurs in people with hyperthyroidism, approximately 50% of whom experience at least mild TED, but it can also affect people with hypothyroidism or normal thyroid function.
Despite existing approved treatments for TED, a medical need remains for therapies that are effective, well-tolerated, and have a convenient route of administration.
About Enspryng® (satralizumab)
Enspryng was developed by Chugai, a member of the Roche Group, and is a humanized monoclonal antibody that targets interleukin-6 (IL-6), a key chemical messenger involved in the body's inflammatory response, receptor activity. Enspryng was designed using novel recycling antibody technology which, compared to conventional technology, allows for sustained IL-6 inhibition by binding strongly and repeatedly to the IL-6 receptor enabling rapid and sustained suppression of inflammatory pathways.
Enspryng is the first and only IL-6 inhibitor treatment currently approved in approximately 90 countries for neuromyelitis optica spectrum disorder (NMOSD), including in the United States and European Union, with a well-established safety profile in over 10,000 patients.
Genentech is committed to developing Enspryng in additional neurological autoimmune and inflammatory diseases that may benefit from inhibition of IL-6 signalling, including autoimmune encephalitis (AIE) and myelin oligodendrocyte glycoprotein antibody-associated disease (MOGAD). Genentech recently announced positive Phase III results for Enspryng in MOGAD, with regulatory submissions planned this year.
Enspryng has orphan drug designation in the United States and European Union for treatment of NMOSD, and investigational orphan drug designation in the U.S. for MOGAD, anti-NMDA receptor autoimmune encephalitis (anti-NMDAR AIE), and leucine-rich glioma-inactivated 1 autoimmune encephalitis (LGI1 AIE).
Indications and Important Safety Information
What is Enspryng? Enspryng is a prescription medicine used to treat neuromyelitis optica spectrum disorder (NMOSD) in adults who are aquaporin-4 (AQP4) antibody positive. It is not known if Enspryng is safe and effective in children. Who should not receive Enspryng?Do not take Enspryng if you:
What is the most important information I should know about Enspryng? Enspryng may cause serious side effects including:
Your healthcare provider will check if you have an infection and treat it if needed before you start or continue to take Enspryng.
Before you take Enspryng, tell your healthcare provider about all of your medical conditions, including if you:
Tell your healthcare provider about all the medicines you are taking, including prescription and over-the-counter medicines, vitamins, and herbal supplements.
What are the most common side effects of Enspryng?
The most common side effects of Enspryng include:
These are not all the possible side effects of Enspryng.
Call your doctor for medical advice about side effects. You may report side effects to FDA at 1-800-FDA-1088. You may also report side effects to Genentech at 1-888-835-2555.
For more information, go to https://www.enspryng.com/ or call 1-844-NSPRYNG.
For additional safety information, please see the full Prescribing Information and Medication Guide.
About Genentech in Ophthalmology
Genentech is researching and developing new treatments for people living with a range of eye diseases that cause significant visual impairment and blindness, including wet age-related macular degeneration (AMD), diabetic macular edema (DME), diabetic retinopathy (DR), geographic atrophy (GA) and other retinal diseases, including rare and inherited conditions.
About Genentech
Founded 50 years ago, Genentech is a leading biotechnology company that discovers, develops, manufactures and commercializes medicines to treat patients with serious and life-threatening medical conditions. The company, a member of the Roche Group, has headquarters in South San Francisco, California. For additional information about the company, please visit http://www.gene.com.
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