Diroximel fumarate, sold under the brand name Vumerity, is a medication used for the treatment of relapsing forms of multiple sclerosis (MS).

[7] Diroximel fumarate was approved for medical use in the United States in October 2019,[8] and in the European Union in November 2021.

[7] In the US, it is additionally approved for other relapsing forms of MS such as clinically isolated syndrome and active secondary progressive disease.

[7][10] Under the European Union's label, the drug is contraindicated in people with progressive multifocal leukoencephalopathy (PML),[7] a disease of the brain caused by a virus.

A rare but potentially fatal adverse effect may be PML, which has been observed under treatment with dimethyl fumarate.

Its active metabolite, monomethyl fumarate, has a relatively low plasma protein binding of 27 to 45%.

[9] After ingestion, the substance is cleaved by esterase enzymes before reaching the systemic circulation, resulting in monomethyl fumarate (MMF), the active metabolite, and hydroxyethyl succinimide (HES), which is inactive.

[9] MMF is further metabolized to fumarate, citrate and glucose, ultimately entering the citric acid cycle and being broken down to carbon dioxide (CO2).

[12] The applicant for this medicinal product is Biogen Netherlands B.V.[12] Diroximel fumarate was approved for medical use in the European Union in November 2021.