Neuromyelitis optica spectrum disorder (NMOSD) is an autoimmune disorder that mostly affects the eyes and spinal cord. In most people with NMOSD, the immune system attacks a specific protein, called aquaporin-4 (AQP4). Inflammation from these attacks can damage the optic nerves and spinal cord, causing loss of vision and trouble moving or walking. There is no cure for NMOSD. Treatment usually consists of medicines to help reduce inflammation, ease symptoms, and prevent future attacks (relapses).
Enspryng (satralizumab-mwge) is a biologic medicine that may help prevent relapses in adults with NMOSD who have anti-AQP4 antibodies in their blood.
How Does Enspryng Work?
Neuromyelitis optica spectrum disorder (NMOSD) is a rare disorder where your immune system attacks healthy cells in the central nervous system (brain and spinal cord). In most people with NMOSD, the immune system makes an antibody that mistakenly targets a protein in your central nervous system called aquaporin-4 (AQP4). This causes inflammation of the optic nerve (which carries messages from your eye to your brain) and the spinal cord, which can lead to vision loss, muscle weakness, and other symptoms as shown in the table below.
Table 1. Symptoms of Neuromyelitis Optica Spectrum Disorder
Inflammation of the optic nerve, also called optic neuritis |
|
Inflammation of the spinal cord, also called transverse myelitis |
|
Your health care provider will focus on treating your symptoms and preventing relapses with steroids or biologic medicines. However, relapses can still happen despite treatment. Newer medicines focus on preventing relapses by targeting specific parts of the immune system. Enspryng blocks the receptor for a protein called interleukin-6 (IL-6). IL-6 is thought to play a role in the inflammation caused by anti-AQP4 antibodies. By blocking IL-6, Enspryng can help reduce relapses in people with NMOSD who test positive for anti-AQP4 antibodies.
How Should I Use This Medicine?
Enspryng is a medicine that is injected under the skin either into the lower part of your stomach area (abdomen), avoiding the area around your belly button, or the front and middle part of your thigh. The first three injections are given every 2 weeks, followed by injections every 4 weeks. It is important to track your injections and stay on a regular schedule. Use a calendar or set a reminder on your phone to help keep the schedule. If you miss an injection, talk to your health care provider about when and how to restart your injections.
Your health care provider will train you on the correct way to give the injection, the places on your body where you can inject, and how to rotate sites for each injection. Always wash your hands before injecting. The drugmaker has an instructional video that can be found at www.enspryng.com.
Keep Enspryng in the refrigerator. Do not freeze or shake the medicine. Keep it in the original carton to protect it from light. Allow 30 minutes for the medicine to come to room temperature before giving the injection. Do not warm the medicine in any way, such as in the microwave or under warm water.
Talk with your health care provider about any vaccines that you may need. You should not receive certain vaccines right before or while using Enspryng. Tell your health care provider about any vaccines you have recently received or have scheduled.
How Was It Studied?
Two studies have been done to look at the safety and efficacy of Enspryng for the treatment of neuromyelitis optica spectrum disorder (NMOSD) when compared with placebo. Placebo-controlled studies compare a medicine with a placebo (a treatment with no active medicine) to help researchers see its true benefits and risks.
To be included in both studies, people had to have a diagnosis of NMOSD with or without aquaporin-4 (AQP4) antibodies in their blood, evidence of relapses, and an Expanded Disability Status Scale (EDSS) score between 0 and 6.5. The use of EDSS helps understand the amount of disability caused by NMOSD symptoms, where 0 is no disability and 6.5 is needing two canes or crutches to walk. People were assigned to receive either Enspryng injections or placebo. The table below provides more information about the the people in the studies who were anti-AQP4 antibody positive and received Enspryng.
Table 2. Study Participants
Study 1 | Study 2 | |
|---|---|---|
Other medicines | Not taking other immune-suppressing medicines | Taking other immune-suppressing medicines like oral corticosteroids, azathioprine, or mycophenolate mofetil |
Relapses | At least one in the past year | At least two in the past two years |
Average age | 44 | 46 |
Gender | Female (76%) | Female (100%) |
Race or Ethnicity | White (50%) Black or African American (22%) Asian (20%) | White (46%) Asian (52%) |
Average EDSS Score | 3.8 | 4.0 |
Median treatment duration | 95.9 weeks | 143.1 weeks |
Efficacy in the study was based on the time to the first relapse, which was defined as new or worsening neurological symptoms and increase in the EDSS score.
Other outcomes the researchers looked at included changes to the Visual Analog Scale (VAS) pain score and the Functional Assessment of Chronic Illness Therapy (FACIT) fatigue score.
- VAS measures pain based on a 0 to 100 scale, where 0 is no pain and 100 is “pain as bad as it can be.”
- FACIT fatigue score is based on 13 questions that measures fatigue (tiredness) and asthenia (feeling unusually tired or weak).
What Benefits Were Seen in the Studies?
In both studies, fewer people in the Enspryng group had a relapse compared with people in the placebo group. This means that Enspryng may reduce how often you have an attack of symptoms. For patients without anti-AQP4 antibodies, there was no evidence of benefit from Enspryng compared with placebo.
Table 3. Relapse Rates for People with NMOSD and Anti-AQP4 Antibodies
Enspryng | Placebo | |
|---|---|---|
STUDY 1 – Enspryng alone | ||
Relapse | 22% | 56.5% |
Reduction in risk of relapse | 74% | |
STUDY 2 – Enspryng with other immune-suppressing medicines | ||
Relapse | 11.5% | 42.3% |
Reduction in risk of relapse | 78% | |
There was no significant difference seen with changes in VAS or FACIT fatigue scores for people taking Enspryng compared with people taking placebo.
Your results may differ from what was seen in clinical studies. You and your health care provider should determine if the benefits outweigh any potential risks.
When Will the Medicine Start Working?
After a few months, you may see improvements in the frequency or severity of your symptoms. The long-term goal is to slow progression and prevent relapses, so it is important to track the following symptoms and review them with your health care provider.
- Vision changes
- Strength or ability to walk without assistance
- Numbness or tingling sensations in the hands, feet, arms, and legs
Keep all appointments with your health care provider while you are using Enspryng, even if you don't feel changes in your symptoms right away. Your health care provider may also monitor your progress through blood, imaging, or physical tests.
Who Should Not Receive Enspryng?
You should not receive Enspryng if you have an allergy to it or any of the ingredients, have an active hepatitis B infection, or have active or untreated tuberculosis. Your health care provider may do blood tests before starting Enspryng to check for hepatitis B or tuberculosis.
How Can I Prevent and Manage Side Effects?
The most common side effects of Enspryng include infection of the nose and throat, headache, nausea, rash, gastritis, tiredness, and pain in your arms, legs, or joints. Tell your health care provider if you have any of these symptoms.
Infections. Enspryng can increase the risk of common or serious infections. Tell your health care provider if you are being treated for an infection, or contact them if you have the following signs of an infection:
- Chills, feeling tired, aches, fever, sore throat, or a cough that will not go away
- Skin redness or swelling
- Diarrhea, stomach pains, or feeling sick
- Burning when you urinate (pee) or urinating more often
Nausea. Tell your health care provider if you have nausea that is bothersome. They may give you medicine for nausea and give guidance on possible diet changes to help ease the symptoms. Make sure that you stay hydrated, drinking plenty of water.
Gastritis. Gastritis is an inflammation or irritation in the lining of your stomach. Tell your health care provider if you have stomach problems, including upset stomach, nausea, bloating, stomach pain, or loss of appetite.
Rash. Call your health care provider if you get a rash while using Enspryng. Get emergency help if this rash spreads to other areas of the body.
These are not all of the possible side effects. Talk with your health care provider if you are having symptoms that bother you. In the U.S., you can report side effects to the FDA at www.fda.gov/medwatch or by calling 800-FDA-1088 (800-332-1088). In Canada, you can report side effects to Health Canada at www.health.gc.ca/medeffect or by calling 866-234-2345.
What Monitoring or Blood Tests May I Need Before Starting or During Treatment?
Before starting Enspryng, your health care provider may do blood tests to check the health of your liver or to see if you have active hepatitis B, untreated tuberculosis, or other signs of infection. These tests may be repeated during treatment. It is important to keep all appointments for lab work.
What Types of Interactions Can Happen?
There are no known interactions between Enspryng and food, drinks, or other medicines. However, Enspryng may intearct with certain vaccines. Tell your pharmacist or other health care provider about all prescription or over-the-counter (OTC) medicines, vitamins/minerals, herbal products, or other supplements you take or have recently taken. Contact your health care provider if you believe you are having side effects due to a potential interaction.
Getting Your Medicine: What to Expect
Enspryng is considered a specialty medicine, which is a high-cost medication that is taken for rare, complex, or long-term (chronic) diseases. It may require a different process than picking up your prescription at a local pharmacy. This process helps you stay on track with your treatment. Your health care provider will work with you, your insurance company, and/or the drugmaker to start the process.
Here are some differences that you may expect.
Insurance approval. Your insurance may require approval for using this medicine, also called a prior authorization. The insurance company reviews the prescription from your health care provider to make sure it is covered and determines the process that needs to be followed.
Pharmacy access. You may be required to use a specific pharmacy to get your medicine. Your health care provider will work with you and your insurance company on which pharmacy to use and the information that will be provided.
Copay assistance. There is a copay assistance program from the drugmaker that may allow you to pay $0 for your prescription. Whether you are eligible depends on whether you have prescription insurance and what type of insurance you have. If you don’t have insurance, there may be assistance based on specific financial criteria. You can find out more at www.enspryng.com/nmosd/financial-support/assistance-options.html or by calling 844-677-7964.
