Study design

ENSPRYNG® has been studied in two pivotal Phase 3 clinical trials1

Two 24-week, identical, randomized, double-masked, placebo-controlled, multicenter studies of ENSPRYNG vs placebo for TED.1

Patients were randomized to receive ENSPRYNG 120 mg or placebo administered subcutaneously at Weeks 0, 2, and 4, and once every 4 weeks through Week 20, receiving a total of 7 doses. Patients were then assessed at Week 24.1,2

Overall, 238 patients (92.2%) completed the studies through Week 24. Patient age ranged from 19 to 80 years (median age, 49.4 years).1

Key inclusion criteria1

  • A clinical diagnosis of active TED, defined as a Clinical Activity Score (CAS) ≥3 and proptosis ≥3 mm above normal in the study eye1

or

  • A clinical diagnosis of stable, chronic inactive TED, defined as CAS <3 and proptosis ≥3 mm above normal1

and

  • All patients must be euthyroid at baseline or have mild hypo- or hyperthyroidism (defined as free T3 and free T4 within 50% above or below the normal range at screening)1

Key exclusion criteria1

  • Patients with prior surgical or biologic treatment for TED were excluded1

Baseline characteristics in patients with active and inactive TED2

*Unless stated.
†Includes Black or African American, Native Hawaiian, or Other Pacific Islander, multiple, not reported, and unknown.
‡Patients may be included in ≥1 category.
§Initial diagnosis to randomization.

CAS=Clinical Activity Score; Q4W=every 4 weeks; SD=standard deviation; T3=triiodothyronine; T4=thyroxine; TED=thyroid eye disease; W2=week 2; W4=week 4.

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Dosing and administration

What could the flexibility of self-administration mean for your patients?

Important Safety Information & Indication

Indication

ENSPRYNG® (satralizumab-mwge)  is indicated for the treatment of thyroid eye disease (TED) regardless of TED activity or duration in adult patients.

Contraindications

ENSPRYNG is contraindicated in patients with a known hypersensitivity to satralizumab or any of the inactive ingredients, an active hepatitis B infection, or active or untreated latent tuberculosis.

Warnings and Precautions

Infections
An increased risk of infections, including serious and potentially fatal infections, has been observed in patients treated with IL-6 receptor antagonists, including ENSPRYNG. The most common infections reported in a randomized clinical trial of patients treated with ENSPRYNG who were not on other chronic immunosuppressant therapies, and that occurred more often than in patients receiving placebo, were nasopharyngitis (12%) and cellulitis (10%). The most common infections in patients who were on an additional concurrent immunosuppressant, and that occurred more often than in patients receiving placebo, were nasopharyngitis (31%), upper respiratory infection (19%), and pharyngitis (12%). Delay ENSPRYNG administration in patients with an active infection, including localized infections, until the infection is resolved.

Hepatitis B Virus (HBV) Reactivation
Risk of HBV reactivation has been observed with other immunosuppressant therapies. Patients with chronic HBV infection were excluded from clinical trials. Perform HBV screening in all patients before initiation of treatment with ENSPRYNG. Do not administer ENSPRYNG to patients with active hepatitis. For patients who are chronic carriers of HBV [HBsAg+] or are negative for HBsAg and positive for HB core antibody [HBcAb+], consult liver disease experts before starting and during treatment with ENSPRYNG.

Tuberculosis
Tuberculosis has occurred in patients treated with other IL-6 receptor antagonists. Patients should be evaluated for tuberculosis risk factors and tested for latent infection prior to initiating ENSPRYNG. Consider anti-tuberculosis therapy prior to initiation of ENSPRYNG in patients with a history of latent or active tuberculosis in whom an adequate course of treatment cannot be confirmed, and for patients with a negative test for latent tuberculosis but having risk factors for tuberculosis infection. Consult infectious disease experts regarding whether initiating anti-tuberculosis therapy is appropriate before starting treatment. Patients should be monitored for the development of signs and symptoms of tuberculosis with ENSPRYNG, even if initial tuberculosis testing is negative.

Vaccinations
Live or live-attenuated vaccines should not be given concurrently with ENSPRYNG because clinical safety has not been established. Administer all immunizations according to immunization guidelines at least 4 weeks prior to initiation of ENSPRYNG for live or live-attenuated vaccines and, whenever possible, at least 2 weeks prior to initiation of ENSPRYNG for non-live vaccines.

Elevated Liver Enzymes
Mild and moderate elevations of liver enzymes have been observed in patients treated with ENSPRYNG at a higher incidence than in patients receiving placebo. ALT and AST levels should be monitored every 4 weeks for the first 3 months of treatment, followed by every 3 months for one year, and thereafter, as clinically indicated.

Decreased Neutrophil Counts
Decreases in neutrophil counts were observed in patients treated with ENSPRYNG at a higher incidence than placebo. Neutrophil counts should be monitored 4 to 8 weeks after initiation of therapy, and thereafter at regular clinically determined intervals.

Hypersensitivity Reactions
Hypersensitivity reactions, including rash, urticaria, and fatal anaphylaxis, have occurred with other IL-6 receptor antagonists.


Use in Specific Populations

Pregnancy
There are no adequate data on the developmental risk associated with the use of ENSPRYNG in pregnant women. In an animal reproduction study, no adverse effects on maternal animals or fetal development were observed in pregnant monkeys and their offspring, with administration of ENSPRYNG at doses up to 50 mg/kg/week. In the U.S. general population, the estimated background risk of major birth defect and miscarriage in clinically recognized pregnancies is 2 – 4% and 15 – 20%, respectively. The estimated background risk of major birth defects and miscarriage for the indicated population is unknown. ENSPRYNG should be used in pregnancy only if the potential benefit justifies the potential risk to the fetus.

Lactation
No information is available on the presence of ENSPRYNG in human milk, the effects of ENSPRYNG on the breastfed infant, or the effects of ENSPRYNG on milk production. ENSPRYNG was excreted in the milk of lactating monkeys administered ENSPRYNG throughout pregnancy. Human IgG is excreted in human milk and the potential for absorption in the infant is unknown. The developmental and health benefits of breastfeeding should be considered along with the mother’s clinical need for ENSPRYNG and any potential adverse effects on the breastfed infant from ENSPRYNG or from the underlying maternal condition.

Pediatric Use
Safety and effectiveness in pediatric patients have not been established.

Geriatric Use
Clinical studies of ENSPRYNG did not include sufficient numbers of patients aged 65 years and older to determine whether they respond differently from younger patients. However, population pharmacokinetic analyses in patients with NMOSD did not show that age affected the pharmacokinetics of ENSPRYNG. In general, caution should be used when dosing the elderly, reflecting the greater frequency of decreased hepatic, renal, or cardiac function, and of concomitant diseases or other drug therapy.

Most Common Adverse Reactions
The most common adverse reactions in patients with TED (incidence ≥5% and greater than placebo) were upper respiratory tract infection (5%), and alanine aminotransferase increased (5%).

You may report side effects to the FDA at (800) FDA-1088 or www.fda.gov/medwatch. You may also report side effects to Genentech at (888) 835-2555.

For additional safety information, please see the full Prescribing Information and Medication Guide.

    • ENSPRYNG [package insert]. South San Francisco, CA: Genentech, Inc; 2026.

      ENSPRYNG [package insert]. South San Francisco, CA: Genentech, Inc; 2026.

    • Subramanian P, et al. Presented at North American Neuro-Ophthalmology Society (NANOS) 52nd Annual Meeting. March 20-24, 2026.

      Subramanian P, et al. Presented at North American Neuro-Ophthalmology Society (NANOS) 52nd Annual Meeting. March 20-24, 2026.

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      Bennett JL, et al. Neurol Neuroimmunol Neuroinflamm. 2025;12(5):e200450.

    • Murdock J, et al. Front. Ophthalmol. 2025; 5:1544436.

      Murdock J, et al. Front. Ophthalmol. 2025; 5:1544436.

    • Ezra DG, et al. Rev Endocr Metab Disord. 2026; 27(2):237-253.

      Ezra DG, et al. Rev Endocr Metab Disord. 2026; 27(2):237-253.

    • Ezra DG, et al. Ophthalmol Ther. 2025; 14(12):3119-3132.

      Ezra DG, et al. Ophthalmol Ther. 2025; 14(12):3119-3132.

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