Multiple sclerosis (MS) is a chronic inflammatory central nervous system disease that causes bothersome or disabling physical symptoms, including problems with mobility, vision, coordination, cognitive function, fatigue and pain.
If you've been diagnosed with relapsing-remitting MS, your doctor is likely to recommend immediate treatment with medications known as disease-modifying therapy (DMT). DMTs have been shown to reduce the number of MS relapses and delay progression of disability to some degree.
Recently, the Food and Drug Administration (FDA) approved the first DMT for primary progressive MS.
Available DMTs differ in how often they're taken, how they're taken, side effects and whether they can be taken during pregnancy. An understanding of DMTs can help you and your doctor form the best treatment strategy for your relapsing-remitting MS.
Interferon beta drugs. These medications are among the first DMTs approved for relapsing MS and are still used as first-line therapy. They include:
- Avonex (interferon beta-1a)
- Betaseron (interferon beta-1b)
- Extavia (interferon beta-1b)
- Rebif (interferon beta-1a)
- Plegridy (peginterferon beta-1a)
Known as immunomodulatory drugs, the exact mode of action of these medications is unknown, but interferon beta is thought to target various immune cells and proteins that play an important role in the inflammatory activity of MS.
The interferon beta medications are given by self-injection, either under the skin or in the muscle. The frequency of injections varies from once every two weeks to three times weekly.
These drugs have comparable effectiveness, reducing the relapse rate by about one-third and slowing the development of new MS-related brain lesions for relapsing MS.
These drugs are considered generally safe and require minimal monitoring. Flu-like symptoms and injection site reactions, such as redness and discomfort, are commonly reported side effects of interferon beta drugs.
Glatiramer acetate (Copaxone, Glatopa). This also is considered an initial therapy option for relapsing MS. Exactly how glatiramer acetate works is unknown, though it's thought to act through immune system cells known as T cells. It may also have potential nerve-protecting effects.
Glatiramer acetate is given by self-injection under the skin, either three times weekly or every day. It's generally well-tolerated, but injection site reactions, such as redness and discomfort, are commonly reported.
Ocrelizumab (Ocrevus). This is the first drug approved by the FDA to treat both relapsing MS and primary progressive MS. Not only has it been shown to reduce relapses, but it slows disease progression.
Ocrelizumab is given as an IV infusion initially twice in two weeks. After that, the infusion is given every six months. Infusion reactions, such as a headache, rash, nausea and fever, are common. Your doctor might recommend that you be given a corticosteroid and an antihistamine before infusion to help prevent reactions.
People with hepatitis B shouldn't take ocrelizamab.
Natalizumab (Tysabri) is a humanized monoclonal antibody that acts by reducing the migration of immune cells across the blood-brain barrier into the central nervous system. This medication is given intravenously every four weeks.
Natalizumab is effective against relapsing MS, reducing the relapse rate by about two-thirds. However, it is associated with a small but important risk of a serious brain infection known as progressive multifocal leukoencephalopathy (PML).
People who take natalizumab must be closely monitored for symptoms of PML, which include progressive weakness and visual or cognitive changes that may not be reversible.
A person's ongoing PML risk is assessed using factors such as:
- The presence of antibodies to the John Cunningham virus on blood testing
- Previous treatment of immunosuppressive drugs, such as mitoxantrone
- Taking natalizumab longer than two years
Alemtuzumab (Lemtrada). This drug helps reduce relapses of MS by targeting a protein on the surface of immune cells and depleting white blood cells. This effect can limit potential nerve damage caused by the white blood cells, but it also increases the risk of infections and autoimmune disorders.
Treatment with alemtuzumab involves five consecutive days of drug infusions followed by three days of infusions a year later. Infusion reactions, such as a headache, rash, nausea and fever, are common with alemtuzumab.
Due to the risks associated with alemtuzamab, the FDA recommends extensive screening before using the drug. It's only available from registered providers, and people treated with alemtuzumab must be registered in a special drug safety monitoring program.
Mitoxantrone. Mitoxantrone is an immunosuppressive drug that's approved for treating rapidly worsening relapsing MS, and the only medication approved to treat secondary progressive MS, an advanced form of relapsing MS.
It's given intravenously and use is limited to a maximum of two years because of important side effects, including damage to the heart muscle. It is also associated with the development of blood cancers, such as leukemia. Due to these side effects and the availability of other therapies, mitoxantrone is used only in exceptional circumstances.
These oral DMTs are approved for treating relapsing MS.
Fingolimod (Gilenya). This once-daily oral medication reduces the relapse rate of MS. Fingolimod is a unique medication that binds to many different types of body cells. It traps white blood cells in lymph nodes so that they cannot enter the brain and cause new MS lesions.
People with heart disorders or related conditions can't use fingolimod. It temporarily slows the heart rate in almost everyone who takes it, so the first dose must be taken in a clinic under medical supervision. It also requires monitoring of vision because of a risk of buildup of fluid in the macula (macular edema), an area in the center of the retina.
Teriflunomide (Aubagio). Teriflunomide has been approved in two doses, 7 milligrams (mg) and 14 mg, taken once daily. It's generally well-tolerated at both doses. Possible side effects include a headache, diarrhea, nausea, elevation in liver enzymes and hair thinning.
Teriflunomide is known to be harmful to a developing fetus. People with liver conditions also shouldn't use it.
Dimethyl fumarate (Tecfidera). Also known as BG-12, dimethyl fumarate (DMF) is taken twice daily. Common side effects include flushing and gastrointestinal problems, such as diarrhea and nausea. Its coating is designed to reduce gastrointestinal problems, and taking it with food also can help relieve them.
DMT treatment strategies
There's no way to know which treatments will work best for you or how your disease will progress. Recommendations are based on several factors, including:
- Recent MS activity, including recent attack frequency, severity and recovery
- The degree of neurological damage based on the neurological examination
- The severity of lesion damage to the brain and spinal cord based on an MRI
- Drug availability and cost
- Other illnesses you have or medications you take that might interact with MS therapy
- Adverse side effects from the MS drugs
- Monitoring requirements
- Your own preferences regarding type of therapy (oral or injectable, for example)
- For women, wanting to conceive a child
Shared decision-making between you and your doctor is the best approach to your MS treatment plan. Each situation is unique, and the best approach is one tailored to your specific needs.