Diroximel fumarate to treat multiple sclerosis.

On October 29, 2019, the Food and Drug Administration (FDA) of the United States approved diroximel fumarate (DRF) as an oral fumarate for the treatment of relapsing forms of multiple sclerosis. Another oral fumarate, dimethyl fumarate (DMF), was approved for the same indication on March 27, 2013. Prior to its approval, DRF did not undergo rigorous testing to determine its efficacy, as its active metabolite, monomethyl fumarate, is the same as that of DMF (bioequivalency). The efficacy, safety and tolerability of DMF have previously been demonstrated in a number of clinical trials and real-world studies. For DRF, one phase III study has been completed, and another is in progress to determine its safety, tolerability and efficacy. In this paper, we review the pharmacology, pharmacokinetics, metabolism, clinical studies and drug safety of DRF.