FDA Approves Genentech’s Treatment for Neuromyelitis Optica Spectrum Disorder (NMOSD)

August 14th, 2020

On August 14, 2020, the FDA approved Genentech’s EnspryngTM (satralizumab-mwge) as the first and only subcutaneous treatment for adults living with anti-aquaporin-4 (AQP4) antibody positive neuromyelitis optica spectrum disorder (NMOSD). NMOSD is a rare, lifelong and debilitating autoimmune disorder of the central nervous system, often misdiagnosed as multiple sclerosis, that primarily damages the optic nerve(s) and spinal cord, causing blindness, muscle weakness and paralysis.


News in brief

  • Enspryng is the first and only FDA-approved subcutaneous treatment option for anti-aquaporin-4 antibody positive NMOSD that can be self-administered by a person with NMOSD or a caregiver every four weeks.
  • Enspryng is also the first and only approved therapy for NMOSD designed to target and inhibit interleukin-6 (IL-6) receptor activity, using novel recycling antibody technology.
  • The approval is supported by one of the largest clinical trial programs undertaken for this rare disease.

Supporting Information

Important Safety Information

Who should not receive ENSPRYNG?

Do not take ENSPRYNG if you: 

  • are allergic to ENSPRYNG or any of the ingredients in ENSPRYNG.
  • have an active hepatitis B infection.
  • have active or untreated inactive (latent) tuberculosis.

What is the most important information I should know about ENSPRYNG?

Enspryng may cause serious side effects including:

  • Infections. ENSPRYNG can increase your risk of serious infections some of which can be life-threatening. Talk to your healthcare provider if you are being treated for an infection, or call them right away if you think you have signs of an infection, with or without a fever, such as:
    • chills, feeling tired, muscle aches, cough that will not go away or a sore throat
    • skin redness, swelling, tenderness, pain or sores on your body
    • diarrhea, belly pain, or feeling sick
    • burning when you urinate or urinating more often than usual

    Your healthcare provider will check if you have an infection and treat it if needed before you start or continue to take ENSPRYNG.

  • Your healthcare provider should test you for hepatitis and tuberculosis (TB) before you start taking ENSPRYNG.
  • All required vaccinations should be completed before starting ENSPRYNG. People using ENSPRYNG should not be given ‘live’ or ‘live-attenuated’ vaccines. ‘Live’ or ‘live-attenuated’ vaccines should be given at least 4 weeks before you start ENSPRYNG. Your healthcare provider may recommend that you get a ‘non-live’ (inactivated) vaccine, such as some of the seasonal flu vaccines. If you plan to get a ‘non-live’ (inactivated) vaccine, it should be given, whenever possible, at least 2 weeks before you start ENSPRYNG.
  • Increased liver enzymes.

    Your healthcare provider should order blood tests to check your liver enzymes before and while you are taking ENSPRYNG. Your healthcare provider will tell you how often you will need to have these blood tests. Make sure you get all of your follow-up blood tests as ordered by your healthcare provider. Your healthcare provider will tell you if you need to wait to start ENSPRYNG if your liver enzymes are increased.

  • Low neutrophil count.

    ENSPRYNG can cause a decrease in your neutrophil counts in your blood. Neutrophils are white blood cells that help the body fight off bacterial infections. Your healthcare provider should order blood tests to check your neutrophil count while you are taking ENSPRYNG.

  • Serious allergic reactions

    Serious allergic reactions that may be life-threatening have happened with other medicines like ENSPRYNG. Tell your healthcare provider before taking your next dose if you had hives, rash, or flushing after your injection. Seek medical attention right away if you have any symptoms of a serious allergic reaction, such as:

    • shortness of breath or trouble breathing 
    • dizziness or feeling faint 
    • swelling of lips, face, or tongue
    • moderate or severe stomach (abdominal) pain or vomiting
    • chest pain

Before you take ENSPRYNG, tell your healthcare provider about all of your medical conditions, including if you:

  • have or think you have an infection.
  • have liver problems.
  • have ever had hepatitis B or are a carrier of the hepatitis B virus.
  • have had or have been in contact with someone with tuberculosis.
  • have had a recent vaccination or are scheduled to receive any vaccination.
  • are pregnant, think that you might be pregnant, or plan to become pregnant. It is not known if ENSPRYNG will harm your unborn baby.
    • Pregnancy Registry: There is a registry for pregnant women who take ENSPRYNG. The purpose of this registry is to check the health of the pregnant mother and her baby. If you are pregnant or become pregnant while taking ENSPRYNG, talk to your healthcare provider about how you can join this pregnancy registry or you may contact the registry at 1-833-277-9338 to enroll.
  • are breastfeeding or plan to breastfeed. It is not known if ENSPRYNG passes into your breast milk. Talk to your healthcare provider about the best way to feed your baby if you take ENSPRYNG.

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:

  • sore throat, runny nose (nasopharyngitis)
  • rash
  • fatigue
  • extremity pain
  • headache
  • upper respiratory tract infection
  • nausea
  • inflammation of the stomach lining (gastritis)
  • joint pain (arthralgia)

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 www.ENSPRYNG.com or call 1-844-NSPRYNG.

Please see the full Prescribing Information and Medication Guide.


Levi Garraway, M.D., Ph.D.

“Today’s FDA approval of Enspryng, the first subcutaneous NMOSD treatment using novel recycling antibody technology, builds upon the work we’ve done in multiple sclerosis with Ocrevus to develop first-in-class medicines and further the scientific understanding of neuroimmunological diseases. We thank the NMOSD community, including patients and investigators who participated in Enspryng clinical trials.”