Your doctor may prescribe an off-label drug to treat multiple sclerosis (MS). This refers to a drug that is not approved by the US Food and Drug Administration (FDA) to treat MS. The drug is approved to treat a different condition, but it may make sense to use it to treat MS if other treatments are not working.1
The FDA has not determined whether these drugs are safe and effective when used to treat MS. But this does not mean that they are unsafe. It often just means that there is limited clinical trial evidence of their benefits for MS. Talk to your doctor about the risks and benefits of off-label drugs.1
Examples of off-label drugs for MS
Off-label drugs commonly used to treat MS include the following.
Cellcept® (mycophenolate mofetil)
Cellcept® (mycophenolate mofetil) is an immunosuppressant drug. It is approved to prevent organ rejection after a transplant. It works by blocking processes needed for certain white blood cells to make copies of themselves (replicate). Blocking these processes helps reduce immune system activity.2,3
Cellcept is often used off-label to treat autoimmune conditions, including MS. Clinical trials have shown that it can reduce the number of MS relapses. This is why Cellcept may be effective for people with relapsing-remitting MS (RRMS).2,3
Cyclophosphamide
Cyclophosphamide is another immunosuppressant drug. It is approved to treat various types of cancers. It works by binding to DNA and blocking cell division, helping to decrease immune system activity.2,4
Cyclophosphamide is used off-label to treat autoimmune conditions like MS. It may be an effective treatment for people with severe RRMS who do not respond to other treatments. The drug also may be effective for those with tumefactive MS, a rare type of MS that causes a tumor-like growth in the brain.2,4
Imuran® (azathioprine)
Imuran® (azathioprine) is also an immunosuppressant drug. It is approved to prevent organ rejection after kidney transplant and to treat rheumatoid arthritis (RA). Imuran works by blocking cells from making DNA. This prevents certain white blood cells from growing and dividing.2,5
Imuran has been used off-label to treat MS for more than 30 years. It is also often used to treat other autoimmune conditions. Studies have shown that it can reduce the number of relapses in people with RRMS.2,5
Minocycline
Minocycline is an antibiotic drug approved to treat various types of bacterial infections. It is used off-label to treat a number of conditions, including MS. But experts do not yet know how it may work to treat MS.2,6
Studies have shown the benefits of combining minocycline with other MS treatments. This includes less frequent relapses. We need more clinical trials to better understand how to use minocycline to treat MS.2,6
Rituxan® (rituximab)
Rituxan® (rituximab) is a monoclonal antibody. This means it is a protein designed in the lab to target a certain molecule. Rituxan targets a specific protein on the surface of B cells. B cells are white blood cells that help regulate inflammation. Rituxan decreases the number of B cells, which reduces inflammation.2,7
Rituxan is approved to treat several conditions, including some cancers and RA. It is often used off-label to treat immune-mediated conditions, including MS. Rituxan reduces relapses and limits new inflammation in people with RRMS. It also may slow down the progression of the condition, but more research is needed to confirm this.2,7
Statins
Statins are drugs that lower cholesterol. They work by blocking enzymes involved in cholesterol production. Statins are also known to change the immune system. This is why they are sometimes used off-label for conditions like RA and MS.2,8
There is evidence that 1 statin, simvastatin, may have neuroprotective benefits for people with secondary progressive multiple sclerosis (SPMS), but there is no evidence that statins can limit MS relapses. More clinical trials are needed to better understand how statins may have benefits in the progressive forms of MS, especially when combined with other therapies.2,8
Other things to know
All drugs can cause side effects, and side effects can vary depending on the specific drug you are taking. Talk to your doctor about the possible side effects of any drug they prescribe for MS symptoms.
Before beginning treatment for MS, tell your doctor about all your health conditions and any other drugs, vitamins, or supplements you take. This includes over-the-counter drugs.