FDA approved dimethyl fumarate (Tecfidera, Biogen Idec) capsules for the treatment of adults with relapsing forms of multiple sclerosis (MS), including the most common form, relapsing-remitting multiple sclerosis (RRMS), according to an FDA statement on March 27.
Joining two other approved oral disease-modifying medications for MS-fingolimod (Gilenya) and teriflunomide (Augabio), dimethyl fumarate has been shown to significantly reduce relapses and the development of brain lesions and slow disability progression over time.
“No drug provides a cure for multiple sclerosis so it is important to have a variety of treatment options available for patients,” said Russell Katz, MD, director of the Division of Neurology Products in the FDA’s Center for Drug Evaluation and Research. “Multiple sclerosis can impair movement, sensation, and thinking and have a profound impact on a person’s quality of life.”
In two phase 3 clinical trials, DEFINE and CONFIRM, patients with MS who were randomized to dimethyl fumarate had fewer relapses compared to individuals receiving placebo. In the DEFINE trial, the risk of relapse was reduced by 49% in patients receiving dimethyl fumarate 240 mg BID (P<0.0001) and 50% in patients receiving the drug TID (P<0.0001). In addition, the annualized relapse rate was reduced by 53% in patients taking the drug BID and 48% in those taking it TID.
In the CONFIRM trial, patients taking dimethyl fumarate at a dose of 240 mg BID and TID had similar results with a reduction in annualized relapse rate of 44% for BID and 51% for TID. These patients were compared with a control group that received subcutaneous glatiramer acetate (Copaxone) 20 mg daily and a placebo control group. Patients in the CONFIRM trial also had a greater reduced risk of confirmed disability in the BID group (21%) and TID group (24%) than the glatiramer acetate group (7%), according to the company’s press information.
The most common adverse events with dimethyl fumarate were flushing, diarrhea, nausea, and upper abdominal pain. These side effects decrease over time, the FDA noted.
Patients in the clinical trials experienced a decrease in lymphocytes, which can increase the risk of infection. However, during the trials, there were no significant increases in infections among patients who received dimethyl fumarate. The FDA suggests monitoring white blood cell counts before initiating therapy and annually thereafter.
Dimethyl fumarate should be started at a dose of 120 mg BID. It can be increased to 240 mg BID after 1 week at the starting dose.