What Is Enspryng and How Does It Work?
The FDA approved Enspryng (satralizumab) to treat adults with thyroid eye disease, also called TED. TED is a rare immune system condition that causes inflammation around the eyes. It can cause eye swelling, pain, double vision, and bulging eyes.
A protein in the body called interleukin-6, or IL-6, causes swelling and inflammation in people with TED. Enspryng works by blocking IL-6, helping to reduce swelling behind and around the eyes.
Enspryng is given as a shot under the skin that patients or caregivers can give at home after proper training from a healthcare provider.
Why Was Enspryng Approved?
The approval was based on two large clinical studies called SatraGO-1 and SatraGO-2. These trials included 258 adult patients with active or chronic TED. In the studies, patients received either Enspryng or a placebo shot without active medicine.
In SatraGO-2, Enspryng showed clear benefits for patients with active TED. About 53% of patients taking Enspryng had less eye bulging after 24 weeks, compared to 23% of patients taking the placebo. Enspryng also helped reduce double vision. About 61% of patients taking Enspryng saw improvements in double vision, compared to 26% on the placebo. SatraGO-1 did not meet its primary goal at week 24, but the overall group of studies showed meaningful benefits.
Safety results were consistent with how the drug works. The most common side effects seen in TED studies were upper respiratory tract infections and increased liver enzymes. There were no serious infections reported in the Enspryng group during the main TED studies.
What Do I Need to Know?
Enspryng is given as a shot under the skin in your belly or thigh. After initial loading doses given every two weeks for the first three treatments, maintenance doses are given once every four weeks. After getting proper training from your healthcare provider, you or a caregiver can give these injections at home. Always wait 30 minutes for the medicine to reach room temperature before you inject it.
Enspryng can lower your body's ability to fight off infections. Tell your healthcare provider right away if you have signs of an infection, such as a fever, cough, sore throat, or skin redness. Your healthcare provider must test you for hepatitis B and tuberculosis before you start treatment. You must also finish any needed vaccines before starting Enspryng, and you should not receive live vaccines while taking it.
Your healthcare provider will do blood tests before and during treatment to check your liver enzymes and white blood cell levels. The most common side effects of Enspryng include a sore throat, runny nose, headache, upper respiratory tract infection, stomach inflammation, joint pain, rash, fatigue, and arm or leg pain.
Tell your healthcare provider if you are pregnant, planning to become pregnant, or breastfeeding. It is not known if Enspryng will harm a fetus or pass into breast milk. Also, let your healthcare provider know about all prescription drugs, over-the-counter medicines, and supplements you take.