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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

Patients should not take Enspryng if they: 

  • are allergic to satralizumab-mwge or any of the ingredients in Enspryng
  • have an active hepatitis B infection
  • have active or untreated inactive (latent) tuberculosis (TB) 

Enspryng may cause serious side effects including:

  • Infections. Enspryng can increase risk of serious infections some of which can be life-threatening. Patients should speak with their healthcare provider if they are being treated for an infection and call right away if there are 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 the body
    • diarrhea, belly pain, or feeling sick
    • burning when urinating or urinating more often than usual

A healthcare provider will check for infection and treat it if needed before starting or continuing to take Enspryng

    • A healthcare provider should test for hepatitis and TB before initiating 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 a patient starts Enspryng. A healthcare provider may recommend that a patient receive a ‘non-live’ (inactivated) vaccine, such as some of the seasonal flu vaccines. If a patient plans to get a ‘non-live’ (inactivated) vaccine it should be given, whenever possible, at least 2 weeks before starting Enspryng
  • Increased liver enzymes. A healthcare provider should order blood tests to check patient liver enzymes before and while taking Enspryng. A healthcare provider will dictate how often these blood tests are needed. Patients should complete all follow-up blood tests as ordered by a healthcare provider. A healthcare provider may wait to start Enspryng if liver enzymes are increased
  • Low neutrophil count. Enspryng can cause a decrease in neutrophil counts in the blood. Neutrophils are white blood cells that help the body fight off bacterial infections. A healthcare provider should order blood tests to check neutrophil counts while a patient is taking Enspryng
  • Serious allergic reactionsthat may be life-threatening have happened with other medicines like Enspryng. Patients should call their healthcare provider right away if they have any of these symptoms of an allergic reaction:
    • shortness of breath or trouble breathing 
    • swelling of lips, face, or tongue
    • dizziness or feeling faint 
    • moderate or severe stomach (abdominal) pain or vomiting
    • chest pain

Before taking Enspryng, patients should tell their healthcare provider about all of their medical conditions, including if they:

  • have or think they 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 TB
  • have had a recent vaccination or are scheduled to receive any vaccination
  • are pregnant, think they might be pregnant, or plan to become pregnant. It is not known if Enspryng will harm one’s unborn baby
  • are breastfeeding or plan to breastfeed. It is not known if Enspryng passes into breast milk. Patients should speak with their healthcare provider about the best way to feed one’s baby while on treatment with Enspryng

Patients should tell their healthcare provider about all the medicines they take, including prescription and over-the-counter medicines, vitamins and herbal supplements.

The most common side effects of Enspryng include:

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

For more information about the risk and benefit profile of Enspryng, patients should ask their healthcare provider.

Patients may report side effects to the FDA at 1-800-FDA-1088 or http://www.fda.gov/medwatch. Patients may also report side effects to Genentech at 1-888-835-2555.

Please see the full Prescribing Information and Medication Guide for additional Important Safety Information.


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.”