Alternative Preventative Treatment Options: Off-Label Medications

Reviewed by: HU Medical Review Board | Last reviewed: June 2023

Unfortunately, rare diseases like neuromyelitis optica spectrum disorder (NMOSD) may have fewer approved treatment options than more common diseases. Your doctor may discuss treatment options with you that include off-label drugs.

An off-label drug is one that has not been approved by the US Food and Drug Administration (FDA) to treat a certain condition. This also means the FDA has not yet determined the drug is safe and effective when used the way you are taking it.1

Using drugs off-label is common in rare diseases. This is because there often are not many drugs available to treat these conditions. If you and your doctor decide to use an off-label drug, it is important to understand what “off-label” means.

This does not mean the drug is unsafe to take. Often, it means there has not been an official clinical trial to test the drug for this specific rare disease. You should always talk to your doctor about any questions you have about your treatments.1

Some off-label drugs commonly used to treat NMOSD include:

Rituxan® (rituximab)

Rituxan (rituximab) is a biologic drug. Biologic drugs are made from living organisms or cells. The process of making biologics turns products made from organisms or cells into drugs that can prevent, treat, or cure diseases. Biologics are different from most traditional drugs that are made from chemicals in a lab. Their ingredients are not directly derived from living cells.

Rituxan is a monoclonal antibody. This is a lab-made antibody that targets a certain antigen. An antigen is a molecule, usually part of a protein, that is recognized by part of the immune system, like an antibody. Rituxan is an antibody that targets an antigen on B cells, a type of white blood cell in your body that makes antibodies and helps regulate inflammatory responses. Rituxan prevents attacks by decreasing B cells, which results in decreased harmful antibody production and inflammation.2,3

While Rituxan is not FDA-approved for NMOSD, your doctor may consider this drug as a first-line treatment. Doctors have many years of experience successfully treating NMOSD with Rituxan, and several smaller studies support the use of Rituxan in NMOSD.4


Mitoxantrone is a type of antibiotic that is also used as a chemotherapy drug. For those with NMOSD, mitoxantrone is thought to work by targeting a type of white blood cell responsible for a part of the immune response. Mitoxantrone is a powerful immune suppressant, meaning it decreases the immune system response.5-7

The safety and effectiveness of this drug has not been well established, and it may have serious side effects, including heart problems and an increased risk of cancer. Current studies show mixed results.5-7

Campath® and Lemtrada® (alemtuzumab)

Alemtuzumab is a biologic drug that targets lymphocytes, a type of white blood cell. Alemtuzumab is thought to stop or slow the development of central nervous system (CNS) autoimmune diseases such as NMOSD. However, some studies have shown that alemtuzumab may not be helpful. These mixed results are common in off-label drugs, especially those used for rare diseases.8-10

Imuran® and Azasan® (azathioprine)

Azathioprine is an off-label immunosuppressant that may be used for NMOSD. Immunosuppressant drugs lower the immune response, which can lead to fewer NMOSD attacks. However, azathioprine has been linked to negative side effects. Plus, a large number of people continue to relapse while taking the drug.11,12

CellCept® (mycophenolate mofetil, or MMF)

Mycophenolate mofetil, also called CellCept or MMF, is a drug sometimes used to treat NMOSD. MMF suppresses both immune response and antibody formation in NMOSD. Limited studies have shown effectiveness and safety for use in NMOSD. Some results have been positive, with lower rates of relapse.13,14


Methotrexate is what is called a disease-modifying antirheumatic drug (DMARD). It was first introduced as an anti-cancer treatment. It is common to prescribe it for other autoimmune conditions, such as rheumatoid arthritis (RA).15,16

Methotrexate suppresses the immune system in those with NMOSD. Immunosuppression therapy can be expensive, and treatments may not be covered by insurance. Compared to other biologic treatments, methotrexate is inexpensive. This may play a role in helping people to access immunosuppressive therapy as a treatment option.16

Actemra® (tocilizumab)

Actemra (tocilizumab) is a laboratory-made antibody to the IL-6 receptor, which has been shown to play a role in NMOSD. Studies have indicated that this drug may be effective in reducing how often someone has NMOSD attacks. It appears to be especially helpful when other treatments have not worked. However, these studies are limited.17,18

More studies are needed to prove the effectiveness and safety of these drugs when used to treat NMOSD. Like all drugs, unwanted reactions and side effects can occur. Talk to your doctor about the risks and benefits of taking these drugs.17,18

By providing your email address, you are agreeing to our privacy policy.