Mitoxantrone for multiple sclerosis

Last updated Nov. 11, 2025, by Margarida Maia, PhD
Fact-checked by Inês Martins, PhD

What is mitoxantrone for MS?

Mitoxantrone is an approved infusion medication that is used to reduce the frequency of relapses and slow the progression of disability in people with certain forms of multiple sclerosis (MS), including relapsing-remitting MS (RRMS) and secondary progressive MS (SPMS).

However, mitoxantrone has many side effects and increases the risk of serious complications, so it is rarely used in MS.

Administered via intravenous infusion, or directly into the bloodstream, mitoxantrone is a chemotherapy drug that interferes with the growth of immune cells, including B-cells, T-cells, and macrophages. These cells play a key role in driving inflammation and nerve cell damage in MS.

By suppressing their function and blocking the release of pro-inflammatory signaling molecules, mitoxantrone is thought to reduce inflammation in MS, helping to prevent relapses and slow the progression of disability in patients.

Mitoxantrone was initially marketed under the brand name Novantrone. However, that medication was removed from the market for reasons other than safety or effectiveness. It is now only available in the U.S. under generic formulations.

In addition to MS, mitoxantrone is also approved for prostate cancer and a form of blood cancer called acute nonlymphocytic leukemia.

Therapy Snapshot

Who with MS can take mitoxantrone?

Mitoxantrone is approved in the U.S. to reduce neurological disability and/or the frequency of relapses in people with certain forms of MS.

According to its U.S. label, these include secondary (chronic) progressive MS, progressive relapsing MS, or worsening relapsing-remitting MS — terms that reflect older classifications. Currently, these categories generally correspond to RRMS with worsening disability and SPMS, whether active or nonactive.

The medication is contraindicated for patients who have experienced any hypersensitivity reactions — serious immune responses, including allergic reactions — to the medication. It should also not be used in MS patients who have issues with the heart’s pumping ability, low numbers of immune cells called neutrophils, or impaired liver function.

Due to the risk of serious side effects, mitoxantrone is usually prescribed only when other treatment options are unavailable or have failed.

How is mitoxantrone administered in MS?

Mitoxantrone is given as a short intravenous infusion every three months, at a dose of 12 milligrams per square meter of body surface area (mg/m²). These infusions typically last between 5 and 15 minutes and are administered by a certified healthcare professional.

People with MS should not receive a cumulative dose of mitoxantrone exceeding 140 mg/m².

Mitoxantrone in MS clinical trials

Mitoxantrone’s approval in the U.S. was primarily based on data from two randomized clinical trials that were conducted in the 1990s and involved a total of 230 participants.

• Study 1, called MIMS, enrolled 194 adults with RRMS and worsening disability between relapses or SPMS with or without relapses. Participants were randomly assigned to receive one of two doses of mitoxantrone or a placebo every three months for two years. Results showed that the now-approved dose significantly slowed disability progression compared with a placebo. This dose also led to significantly fewer changes in walking ability, reduced relapse rates, and lowered the proportion of patients with new active lesions or with new lesions.
• Study 2 enrolled 42 adults with either RRMS or SPMS that was gradually worsening with or without relapses. Participants received mitoxantrone in combination with the corticosteroid methylprednisolone, or methylprednisolone alone, for six months. The data showed that significantly more patients on mitoxantrone had no new active lesions compared with those on methylprednisolone alone (90.5% vs. 31.3%). They also had significantly greater reductions in disability and lower relapse rates.

Mitoxantrone side effects

Side effects that occurred more frequently with mitoxantrone than in control groups in MS clinical trials include:

• nausea
• hair thinning
• missed or irregular menstrual periods
• urinary tract infection
• gastrointestinal issues such as stomach inflammation, diarrhea, and constipation
• weakness
• sore throat

Mitoxantrone also carries a boxed warning noting it can cause serious and sometimes fatal side effects, including:

• heart failure, which can occur during treatment or months to years later, and can be fatal even in people who have never had heart problems before
• leukemia, a blood cancer

Multiple Sclerosis News Today is strictly a news and information website about the disease. It does not provide medical advice, diagnosis, or treatment. This content is not intended to be a substitute for professional medical advice, diagnosis, or treatment. Always seek the advice of your physician or other qualified health provider with any questions you may have regarding a medical condition. Never disregard professional medical advice or delay in seeking it because of something you have read on this website.