A Guide to FDA-Approved Multiple Sclerosis Drugs

Multiple Sclerosis (MS) is a chronic, often unpredictable disease of the central nervous system (brain, spinal cord, and optic nerves). The landscape of MS treatment has significantly evolved, with numerous FDA-approved drugs available to help manage the disease. This guide outlines key categories and considerations for FDA-approved medications, designed to provide helpful, general information. It is crucial to understand that specific treatment decisions should always be made in consultation with a qualified healthcare professional.

1. Understanding the Goals of MS Drug Therapy

FDA-approved drugs for MS primarily fall into two categories: disease-modifying therapies (DMTs) and medications for symptom management. DMTs are designed to reduce the frequency and severity of MS relapses, slow disease progression, and decrease the number and size of lesions in the brain and spinal cord as seen on MRI. Symptom management medications address specific symptoms like fatigue, spasticity, or pain, but do not alter the disease course. This guide focuses mainly on FDA-approved DMTs.

2. Injectable Disease-Modifying Therapies

Injectable DMTs were among the first effective treatments for relapsing forms of MS. They are administered either subcutaneously (under the skin) or intramuscularly (into the muscle).

Interferon Beta Preparations

This class includes drugs such as interferon beta-1a (e.g., Avonex, Rebif) and interferon beta-1b (e.g., Betaseron, Extavia). These medications are thought to work by reducing inflammation and regulating the immune system to decrease the number of relapses and slow disability progression in relapsing forms of MS.

Glatiramer Acetate

Glatiramer acetate (e.g., Copaxone, Glatopa) is another injectable DMT approved for relapsing forms of MS. Its mechanism of action is believed to involve modulating immune system responses, leading to a reduction in MS activity.

3. Oral Disease-Modifying Therapies

Oral DMTs offer a convenient alternative to injectables and have expanded treatment options for many individuals with MS. They are taken as pills or capsules.

Fingolimod and Siponimod

Fingolimod (Gilenya) and siponimod (Mayzent) are sphingosine 1-phosphate (S1P) receptor modulators. They work by trapping certain immune cells (lymphocytes) in the lymph nodes, preventing them from entering the central nervous system and causing damage. Fingolimod is approved for relapsing forms of MS, while siponimod is approved for relapsing forms of MS and active secondary progressive MS (SPMS).

Teriflunomide

Teriflunomide (Aubagio) is an immunomodulator that inhibits the synthesis of pyrimidine, which is necessary for rapidly dividing immune cells. It is approved for relapsing forms of MS.

Dimethyl Fumarate and Diroximel Fumarate

Dimethyl fumarate (Tecfidera) and diroximel fumarate (Vumerity) are thought to exert their effects through activation of the Nrf2 pathway, which has anti-inflammatory and neuroprotective properties. Both are approved for relapsing forms of MS.

Cladribine and Ozanimod/Ponesimod

Cladribine (Mavenclad) is a short-course oral treatment that selectively targets and reduces specific immune cells. Ozanimod (Zeposia) and ponesimod (Ponvory) are also S1P receptor modulators, similarto fingolimod and siponimod, approved for relapsing forms of MS.

4. Infusion-Based Disease-Modifying Therapies

Infusion therapies are administered intravenously (into a vein) at a medical facility, typically on a less frequent schedule than injectables or orals.

Natalizumab

Natalizumab (Tysabri) is a monoclonal antibody that works by preventing immune cells from entering the brain and spinal cord, thereby reducing inflammation and damage. It is approved for relapsing forms of MS.

Ocrelizumab

Ocrelizumab (Ocrevus) is a monoclonal antibody that targets CD20-positive B cells, a type of immune cell implicated in MS pathology. It is approved for relapsing forms of MS and primary progressive MS (PPMS).

Alemtuzumab and Ublituximab

Alemtuzumab (Lemtrada) targets CD52, a protein found on the surface of certain immune cells, leading to their depletion. It is approved for relapsing forms of MS. Ublituximab (Briumvi) is another anti-CD20 monoclonal antibody approved for relapsing forms of MS, including clinically isolated syndrome, relapsing-remitting disease, and active secondary progressive disease.

5. Treatments for Progressive Forms of MS

While most DMTs are approved for relapsing forms of MS, certain medications have received specific FDA approval for progressive forms:

Ocrelizumab for Primary Progressive MS

Ocrelizumab (Ocrevus) is notable for being the first and only FDA-approved DMT specifically indicated for primary progressive MS (PPMS), a form of MS characterized by steadily worsening neurological function from the onset, without early relapses or remissions.

Siponimod for Active Secondary Progressive MS

Siponimod (Mayzent) is approved for active secondary progressive MS (SPMS), where the disease begins with a relapsing-remitting course followed by a gradual worsening of neurological function, often with ongoing disease activity (relapses or new MRI lesions).

6. Key Considerations for MS Treatment Selection

Choosing an appropriate FDA-approved MS drug is a complex decision that involves evaluating several factors, unique to each individual. These considerations typically include the specific diagnosis of MS type (e.g., relapsing-remitting, primary progressive, active secondary progressive), disease activity and progression, potential side effects of the medication, existing health conditions, lifestyle, route of administration preference, and cost or insurance coverage. Regular monitoring by a neurologist is essential to assess treatment effectiveness and manage any side effects. It is vital to engage in an open and thorough discussion with your healthcare team to determine the most suitable treatment plan for your individual circumstances.

Summary

The array of FDA-approved multiple sclerosis drugs has transformed MS management, offering hope for slowing disease progression and improving quality of life. These medications encompass various administration methods, including injectables, orals, and infusions, and target different aspects of the immune system to modify the disease course. Specific treatments like Ocrelizumab and Siponimod also address progressive forms of MS. This guide provides a general overview, but it cannot replace personalized medical advice. Always consult with a qualified healthcare professional for diagnosis, treatment recommendations, and ongoing management of multiple sclerosis.