Relapsing MS generally encompasses clinically isolated syndrome, relapsing-remitting MS, and active secondary-progressive MS. The U.S. Food and Drug Administration (FDA) has approved the following drugs to treat relapsing forms of MS.
Injections
Interferon beta-1a (Avonex and Rebif) and interferon beta-1b (Betaseron and Extavia) are injected into the muscle (intramuscular) or under the skin (subcutaneous). It’s believed that these drugs work by controlling inflammation in the central nervous system (CNS).
Glatiramer acetate (Copaxone, Glatopa) is a subcutaneous injection that attracts immune-system cells (T cells) that would otherwise attack myelin sheaths.
Ofatumumab (Kesimpta) is a self-administered subcutaneous injection that’s taken once a month using a prefilled auto-injector pen. Ofatumumab depletes CD20-positive B lymphocytes, a type of white blood cell believed to be involved in the autoimmune process that leads to the development and progression of MS.
Peginterferon beta-1a (Plegridy) is a longer-lasting form of interferon.
Oral Medications
Teriflunomide (Aubagio) is a once-daily capsule that blocks the production of immune-system cells. Teriflunomide is known from animal studies to cause birth defects. People should stop this medication before trying to conceive, and it should not be used during pregnancy or breastfeeding.
Cladribine (Mavenclad) is a pill that’s taken in two 10-day courses, one year apart. It works by killing T and B cells, preventing them from damaging the nerves in the brain and spinal cord. Cladribine is intended for use in people who have already tried and not responded to or tolerated another MS medication. It’s not recommended for the treatment of clinically isolated syndrome. Cladribine is known to cause birth defects, and both men and women using the drug should avoid conception for six months following a 10-day course of the drug. Women should refrain from breastfeeding for at least seven days following the last dose.
Siponimod (Mayzent) is a pill taken once daily that works similarly to fingolimod. It belongs to the same class of drugs, and while no data is available regarding the use of siponimod during pregnancy, it’s assumed it may have the same effects as fingolimod (Gilenya).
Ponesimod (Ponvory) is an oral tablet taken once daily that works similarly to fingolimod and siponimod. It belongs to the same class of drugs as fingolimod, and while there’s no data available regarding the use of ponesimod during pregnancy, it’s assumed it may have the same effects as fingolimod (Gilenya).
Fingolimod (Tascenso ODT) is an orally disintegrating tablet that’s taken once daily. The drug is a bioequivalent to fingolimod (Gilenya).
Dimethyl fumarate (Tecfidera) is a twice-daily oral capsule that lowers CNS inflammation and the ability of immune cells to get into the CNS. A generic version of Tecfidera is available in the United States.
Diroximel fumarate (Vumerity) is an oral capsule that’s taken twice daily and works similarly to dimethyl fumarate (Tecfidera) but is believed to cause fewer gastrointestinal side effects.
Monomethyl fumarate (Bafiertam) works similarly to dimethyl fumarate and diroximel fumarate and, like them, is taken as a twice-daily capsule.
Ozanimod (Zeposia) is an oral capsule, taken once daily. Ozanimod is one of a class of drugs known as S1P receptor modulators, which sequester cells within lymph nodes, thereby preventing them from entering the CNS and causing inflammation. Ozanimod belongs to the same class of drugs as fingolimod (Gilenya), and while there’s no data available regarding the use of ozanimod during pregnancy, it’s assumed it may have the same effects as fingolimod.
Infusions
Ublituximab (Briumvi) is a monoclonal antibody designed to target B cells — a type of white blood cell — and reduce their numbers. It’s given as a one-hour IV infusion every six months, following the first dose.
Mitoxantrone (Novantrone) is an immunosuppressant drug administered by IV infusion. It requires regular cardiac monitoring, and there’s a total maximum amount an individual can receive over their lifetime. Mitoxantrone isn’t approved to treat clinically isolated syndrome.
Natalizumab (Tysabri) is an IV infusion that works by binding to white blood cells and interfering with their movement from the bloodstream into the CNS.
Second-Line Therapy for Relapsing MS
Alemtuzumab works by rapidly depleting the body’s supply of immune (T and B) cells, which temporarily stops the immune-system effects on the CNS and allows the body to create new cells, which might not attack myelin sheaths.
The FDA recommends using it only as a second-line therapy (after other drugs have failed) because it increases the risk of complications, including severe infections, development of new autoimmune diseases, and other potentially dangerous conditions.
Women taking alemtuzumab should wait four months following treatment to try to conceive. The drug shouldn’t be administered during pregnancy, and women are cautioned against breastfeeding during treatment with alemtuzumab.
Off-Label RRMS Treatment
The monoclonal antibody rituximab (Rituxan), which is considered a high-efficacy MS treatment, isn’t approved to treat MS in the United States but is sometimes prescribed off-label to treat relapsing-remitting MS. It’s administered intravenously in a healthcare setting.
Rituximab works similarly to ocrelizumab, targeting CD20-positive B lymphocytes and destroying them.