The Food and Drug Administration has approved diroximel fumarate (Vumerity) for the treatment of relapsing forms of multiple sclerosis (MS) in adults, including clinically isolated syndrome, relapsing-remitting disease, and active secondary progressive disease, according to an Oct. 30 announcement from its developers, Biogen and Alkermes.
The approval is based on pharmacokinetic studies that established the bioequivalence of diroximel fumarate and dimethyl fumarate (Tecfidera), and it relied in part on the safety and efficacy data for dimethyl fumarate, which was approved in 2013. Diroximel fumarate rapidly converts to monomethyl fumarate, the same active metabolite as dimethyl fumarate.
Diroximel fumarate may be better tolerated than dimethyl fumarate. A trial found that the newer drug has significantly better gastrointestinal tolerability, the developers of the drug announced in July. In addition, the drug application for diroximel fumarate included interim data from EVOLVE-MS-1, an ongoing, open-label, 2-year safety study evaluating diroximel fumarate in patients with relapsing-remitting MS. Researchers found a 6.3% rate of treatment discontinuation attributable to adverse events. Less than 1% of patients discontinued treatment because of gastrointestinal adverse events.
Serious side effects of diroximel fumarate may include allergic reaction, progressive multifocal leukoencephalopathy, decreases in white blood cell count, and liver problems. Flushing and stomach problems are the most common side effects, which may decrease over time.
Biogen plans to make diroximel fumarate available in the United States in the near future, the company said. Prescribing information is available online.