What medications are used to treat Multiple Sclerosis (MS)?

Medications for Multiple Sclerosis

The primary medications used for treating Multiple Sclerosis include disease-modifying therapies (DMTs) such as interferons, sphingosine 1-phosphate receptor modulators, fumarates, monoclonal antibodies, and other immunomodulatory agents that reduce disease activity and slow progression of disability. 1

Disease-Modifying Therapies (DMTs)

Injectable Medications

• Interferons

  • Interferon beta-1a (Avonex) - administered intramuscularly once weekly 2
  • Interferon beta-1b (Betaseron)
  • These reduce annual relapse rates by 29-68% compared to placebo 3
  • Common side effects include flu-like symptoms, injection site reactions, and potential liver injury 2

• Glatiramer Acetate (Copaxone)

  • Synthetic protein that mimics myelin basic protein
  • Administered via subcutaneous injection

Oral Medications

• Dimethyl Fumarate

  • Oral medication taken twice daily
  • Reduces relapse rates and MRI lesions
  • Side effects include flushing, gastrointestinal issues, and potential liver injury 4
  • Requires monitoring of lymphocyte counts due to risk of lymphopenia 4

• Teriflunomide (Aubagio)

  • Inhibits rapidly dividing cells including activated T lymphocytes
  • Once-daily oral medication

• Fingolimod (Gilenya)

  • First oral S1P receptor modulator
  • Prevents lymphocytes from leaving lymph nodes

• Siponimod, Ozanimod, Ponesimod

  • Newer S1P receptor modulators with more selective targeting

• Cladribine (Mavenclad)

  • Oral medication that preferentially depletes lymphocytes
  • Used for highly active relapsing MS 1

Monoclonal Antibodies

• Natalizumab (Tysabri)

  • Targets alpha-4 integrin
  • Highly effective for reducing relapses
  • Risk of progressive multifocal leukoencephalopathy (PML) in JC virus-positive patients 1, 5
  • Requires JCV antibody testing every 6 months 1

• Ocrelizumab (Ocrevus)

  • Anti-CD20 antibody targeting B cells
  • Only FDA-approved medication for primary progressive MS 1, 3
  • Administered via intravenous infusion

• Ofatumumab (Kesimpta)

  • Anti-CD20 antibody
  • Self-administered subcutaneous injection
  • Highly effective for relapsing MS 1

• Alemtuzumab (Lemtrada)

  • Anti-CD52 antibody
  • Administered in two annual treatment courses
  • High efficacy but associated with secondary autoimmune disorders 5

Treatment Selection Based on MS Subtype

Relapsing-Remitting MS (RRMS)

• All DMTs are approved for RRMS
• Selection depends on disease activity, safety profile, and patient preference
• High-efficacy therapies (natalizumab, ocrelizumab, ofatumumab) may be considered for highly active disease 1

Primary Progressive MS (PPMS)

• Ocrelizumab is the only FDA-approved option 1
• Reduces clinical progression compared to placebo

Secondary Progressive MS (SPMS)

• DMTs with proven efficacy in active SPMS include siponimod and some of the medications approved for RRMS
• Treatment options are more limited compared to RRMS

Monitoring Requirements

• Regular MRI monitoring (typically annually) is recommended for all patients on DMTs 1
• Specific monitoring requirements vary by medication:
  • Interferons: Liver function tests, complete blood count
  • Dimethyl fumarate: Lymphocyte counts every 6-12 months 4
  • Natalizumab: JCV antibody testing every 6 months 1
  • Fingolimod: First-dose cardiac monitoring, ophthalmologic exams

Important Considerations

• Early treatment with DMTs is recommended to prevent accumulation of disability 1, 3
• Treatment efficacy varies, with newer agents generally showing higher efficacy but potentially greater risks
• The risk-benefit profile must be carefully considered for each patient
• Vaccination planning is important, particularly with higher-efficacy immunosuppressive therapies 1
• For highly refractory cases, autologous hematopoietic stem cell transplantation (AHSCT) may be considered after failure of high-efficacy DMTs 1

Common Pitfalls to Avoid

• Delaying treatment initiation, which can lead to irreversible disability
• Inadequate monitoring for medication-specific adverse effects
• Failing to consider switching therapy when breakthrough disease activity occurs
• Not accounting for pregnancy planning when selecting therapy for women of childbearing age
• Overlooking the importance of MRI monitoring even in clinically stable patients