Tecfidera (Dimethyl Fumarate)

Tecfidera (dimethyl fumarate) is an oral treatment for multiple sclerosis (MS) that works to help prevent disease relapses and delay disease progression.

In the U.S., Tecfidera was approved in 2013 for adults with relapsing forms of MS – which include clinically isolated syndrome (CIS), relapsing-remitting MS (RRMS), and active secondary progressive MS (SPMS). In other countries, such as the European Union, Canada, and Australia, Tecfidera is solely approved to treat RRMS.

Tecfidera was initially developed and marketed by Biogen. Several generic forms of the therapy are now available in the U.S., including those produced by CiplaGlenmark PharmaceuticalsLupinMylan, and Zydus Cadila.

How Tecfidera works

MS is caused by an abnormal inflammatory attack that the immune system launches against healthy parts of the brain and spinal cord. Tecfidera contains an inactive molecule called dimethyl fumarate (DMF). Once inside the body, this molecule is converted into its active form called monomethyl fumarate (MMF).

It’s not entirely clear how MMF works in MS patients, but generally, the therapy is believed to reduce MS-driving inflammation by changing the activity of immune cells. It also has antioxidant properties that may protect nerve cells against damage.

MMF is also the active agent in Vumerity (diroximel fumarate), a newer MS treatment by Biogen and approved in the U.S. since 2019. Vumerity was designed to deliver a similar amount of MMF as Tecfidera, but with fewer gastrointestinal side effects.

Tecfidera in clinical trials

Approvals of Tecfidera were supported mainly by data from two large Phase 3 clinical trials – DEFINE (NCT00420212) and CONFIRM (NCT00451451). Each study enrolled over 1,200 people with RRMS, and participants were randomized to receive Tecfidera (240 mg, two or three times per day) or a placebo for about two years. In CONFIRM, one patient group was also randomly assigned to glatiramer acetate, an approved MS treatment sold as Copaxone, among other names.

In both studies, significantly fewer participants given twice-daily Tecfidera experienced relapses, compared with those who received a placebo: 27% vs. 46% in DEFINE, and 29% vs. 41% in CONFIRM. The average annual relapse rate was also significantly lower with Tecfidera, by approximately 50% in both studies. For comparison, glatiramer acetate lowered the annual relapse rate by 29% compared with a placebo. Treatment with Tecfidera also significantly decreased brain lesions visible on MRI scans.

In DEFINE, significantly fewer patients given Tecfidera, relative to placebo, experienced a confirmed worsening in disability over the two years (16% vs. 27%). The proportion of patients with worsening disability was not significantly different in CONFIRM.

Participants who completed these studies could enroll in a Phase 3 extension study called ENDORSE (NCT00835770), where all were treated with Tecfidera at 240 mg, either two or three times daily, for years. Results, with a total of 13 years of follow-up, showed that the relapse rate remained low with continued treatment. After about one decade in the extension trial, the average annual relapse rate was 0.11 relapses/year, and about three-quarters of patients had no confirmed disability progression.

A Phase 2 study called FOCUS (NCT02410200)  investigated six months of Tecfidera’s use in children and adolescents, ages 10 to 17, with RRMS. Patients could then enroll in an extension study, called CONNECTED (NCT02555215), and continue with Tecfidera treatment for an additional two years. Results showed that over the 2.5 years of treatment, patients had on average 0.2 relapses per year, representing a 84.5% decrease from before starting on Tecfidera. Most patients showed no signs of disability progression.

Other information

Tecfidera is available in delayed-release capsules of 120 mg or 240 mg. The recommended dose of Tecfidera is 240 mg twice a day, but patients should take 120 mg twice daily over the first week of treatment. The capsules may be taken with or without food; they must be swallowed whole and intact (not crushed, chewed, or sprinkled over food).

The most common side effects associated with Tecfidera include flushing, abdominal pain, diarrhea, and nausea.

Tecfidera may result in liver injury or a substantial decrease in the number of immune cells in the blood. Liver health and blood cell counts should be monitored before starting on Tecfidera and regularly during treatment; the therapy may be discontinued if persistent low immune counts or liver injury occurs.

Treatment with Tecfidera may increase the risk of certain viral infections, such as herpes zoster (shingles). If such an infection develops, the medication may be withheld until the infection resolves. Tecfidera should be stopped immediately if patients show signs of progressive multifocal leukoencephalopathy (PML), a serious brain infection.

Some people experience an allergic or swelling reaction to Tecfidera. The treatment should be discontinued if such a reaction occurs, and Tecfidera should not be given to anyone with a known allergy to its components.

No well-controlled studies of Tecfidera use during pregnancy or lactation in patients exist, but animal data suggest that using the medication at these times can cause harm to a developing fetus. Patients who become pregnant while on Tecfidera may enroll in a registry that is monitoring outcomes in pregnancies with Tecfidera exposure.


Last updated: Feb. 9, 2022, by Marisa Wexler MS


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.

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