What Is Multiple Sclerosis?

Multiple sclerosis (MS) is a lifelong disease that affects your central nervous system (CNS), which is made up of your brain and spinal cord. MS is thought to be an autoimmune disease, a type of condition that causes the immune system to work against the body and attack healthy cells or tissue. In MS, immune cells, which may be triggered in the blood, attack the CNS. The resulting symptoms range in type and severity.

MS affects over 2 million people across the globe, and is about 2-3 times more common in women than in men. An MS diagnosis generally occurs between 20 and 50 years of age, but can happen in those younger or older. In fact, MS is the leading cause of neurological disability in young adults.

The course of MS is different for each person, but there are four disease types that usually occur: Relapsing-Remitting, Primary-Progressive, Secondary-Progressive, and Progressive-Relapsing.

Relapsing-Remitting Multiple Sclerosis

Relapsing-remitting MS (also called relapsing MS) accounts for around 85% of initial MS diagnoses. Flare-ups, or relapses, are visible signs of inflammation in the CNS. They are followed by periods of remission, which could result in complete or near-complete recovery.

AVONEX^® (interferon beta-1a) is approved by the FDA to treat relapsing forms of MS, decreasing the number of flare-ups and slowing the occurrence of physical disability common in people with MS. AVONEX is approved for use in people who have experienced a first attack and have lesions consistent with MS on their MRI.

How Does MS Affect the Body?

While it's unclear exactly how MS causes CNS damage, doctors believe immune cells enter into the CNS and injure tissue. It's thought that when the immune system attacks the CNS, it damages the nerve fiber coating, called myelin, and creates scar tissue or sclerosis (which is how MS got its name).

The nerve fibers, or axons, that make up your CNS send and receive messages to all parts of your body. Myelin typically surrounds axons, adding protection and promoting effective signaling.

The damage to the axons interferes with communications between the CNS and the rest of the body. Because damage to the CNS communication system affects the entire body, symptoms of MS can range from general, such as fatigue, to specific, such as optic neuritis.

Relapsing MS & Disease Progression

Both flare-ups and silent progression can cause relapsing MS to worsen.

Flare-ups

Flare-ups are the most noticeable and unpredictable reminders of relapsing MS. During a flare-up, also known as an exacerbation, attack, or relapse, existing MS symptoms worsen or new symptoms may appear. It's believed flare-ups are visible signs of inflammation in the CNS as the immune system attacks CNS cells. Each flare-up can occur without warning.

A flare-up is defined as lasting at least 24 hours and occurring at least 30 days after a previous flare-up. But flare-ups may vary in severity and can last from a few days to several months. On average, people who don't treat their relapsing MS have about one flare-up per year. While that may not sound like a lot, even infrequent or mild flare-ups can cause permanent damage to your CNS and may lead to future disability.

Silent Progression & Lesions

Even with no symptoms or visible signs, relapsing MS can advance within the CNS. Your neurologist may monitor disease progression using magnetic resonance imaging (MRI) scans. What they're looking for are lesions, or scar tissue, in your CNS. Some common types of lesions that can be studied with MRIs are T1 lesions with gadolinium enhancement (Gd+) and T2 lesions.

• T1 lesions with Gd+ enhancements: Gd+ is a substance that helps your neurologist identify lesions using MRI. T1 lesions are typically thought to be new areas of active inflammation within the CNS.
• T2 lesions: T2-weighted MRIs show the overall number of lesions (lesion load), which can include recent lesion development as well as previous damage.

The link between lesions and physical disability is not well understood.

Indication

AVONEX (interferon beta-1a) is approved by FDA to treat relapsing forms of multiple sclerosis (MS) to decrease the number of flare-ups and slow the occurrence of some of the physical disability that is common in people with MS. AVONEX is approved for use in people who have experienced a first attack and have lesions consistent with MS on their MRI.

Important Safety Information

Before beginning treatment, you should discuss with your healthcare provider the potential benefits and risks associated with AVONEX.

AVONEX can cause serious side effects. Tell your healthcare provider right away if you have any of the symptoms listed below while taking AVONEX.

• Behavioral health problems including depression, suicidal thoughts or hallucinations. Some people taking AVONEX may develop mood or behavior problems including irritability (getting upset easily), depression (feeling hopeless or feeling bad about yourself), nervousness, anxiety, aggressive behavior, thoughts of hurting yourself or suicide, and hearing or seeing things that others do not hear or see (hallucinations).
• Liver problems, or worsening of liver problems including liver failure and death. Symptoms may include nausea, loss of appetite, tiredness, dark colored urine and pale stools, yellowing of your skin or the white part of your eye, bleeding more easily than normal, confusion, and sleepiness. During your treatment with AVONEX you will need to see your healthcare provider regularly and have regular blood tests to check for side effects.
• Serious allergic reactions and skin reactions. Symptoms may include itching, swelling of the face, eyes, lips, tongue or throat, trouble breathing, anxiousness, feeling faint, and skin rash, hives, sores in your mouth, or your skin blisters and peels.

AVONEX will not cure your MS but may decrease the number of flare-ups of the disease and slow the occurrence of some of the physical disability that is common in people with MS. MS is a life-long disease that affects your nervous system by destroying the protective covering (myelin) that surrounds your nerve fibers.

The way AVONEX works in MS is not known. It is not known if AVONEX is safe and effective in children.

Do not take AVONEX if you are allergic to interferon beta, albumin (human), or any of the ingredients in AVONEX.

Before taking AVONEX, tell your healthcare provider if you:

• are being treated for a mental illness, or had treatment in the past for any mental illness, including depression and suicidal behavior.
• have or had bleeding problems or blood clots, have or had low blood cell counts, have or had liver problems, have or had seizures (epilepsy), have or had heart problems, have or had thyroid problems, have or had any kind of autoimmune disease (where the body's immune system attacks the body's own cells), such as psoriasis, systemic lupus erythematosus, or rheumatoid arthritis.
• drink alcohol.
• are pregnant or plan to become pregnant. It is not known if AVONEX will harm your unborn baby. Tell your healthcare provider if you become pregnant during your treatment with AVONEX.
• are breastfeeding or plan to breastfeed. It is not known if AVONEX passes into your breast milk. You and your healthcare provider should decide if you will use AVONEX or breastfeed. You should not do both.

Tell your healthcare provider about all the medicines you take, including prescription and non-prescription medicines, vitamins, and herbal supplements.

AVONEX can cause serious side effects including:

• Heart problems, including heart failure. While AVONEX is not known to have any direct effects on the heart, a few patients who did not have a history of heart problems developed heart muscle problems or congestive heart failure after taking AVONEX. If you already have heart failure, AVONEX may cause your heart failure to get worse. Call your healthcare provider right away if you have worsening symptoms of heart failure such as shortness of breath or swelling of your lower legs or feet while using AVONEX.
  • Some people using AVONEX may have other heart problems including low blood pressure, fast or abnormal heart beat, chest pain, and heart attack or heart muscle problem (cardiomyopathy).
• Blood problems. AVONEX can affect your bone marrow and cause low red and white blood cell, and platelet counts. In some people, these blood cell counts may fall to dangerously low levels. If your blood cell counts become very low, you can get infections and problems with bleeding and bruising.
• Seizures. Some patients have had seizures while taking AVONEX, including patients who have never had seizures before.
• Infections. Some people who take AVONEX may get an infection. Symptoms of an infection may include fever, chills, pain or burning with urination, urinating often, bloody diarrhea, and coughing up mucus.
• Thyroid problems. Some people taking AVONEX develop changes in their thyroid function. Symptoms of thyroid changes include problems concentrating, feeling cold or hot all the time, weight changes, and skin changes.

Tell your healthcare provider right away if you have any of the symptoms listed above.

The most common side effects of AVONEX include:

• Flu-like symptoms. Most people who take AVONEX have flu-like symptoms early during the course of therapy. Usually, these symptoms last for a day after the injection. You may be able to manage these flu-like symptoms by taking over-the-counter pain and fever reducers. For many people, these symptoms lessen or go away over time. Symptoms may include muscle aches, fever, tiredness, and chills.

Call your doctor for medical advice about side effects. You may report side effects to FDA at 1-800-FDA-1088.

Please see the full Prescribing Information and Medication Guide on AVONEX.com for additional important safety information. This information is not intended to replace discussions with your healthcare provider.