Dimethyl fumarate (Tecfidera) a slow releases repurposed variant of dimethyl fumarate (fumiderm) that was first used in psoriasis. Rather than get a once a day variant as the patent ran out, another new variant has been approved in the USA and this has been called vumerity and the active compound is diroximel fumarate, which is taken twice a day
Diroximel fumarate is less likely to cause gastrointestinal side effects, but is as effective as DMF. This is not surprising as the active metabolite of DMF is monmethyl fumarate and this is also the metabolite of diroximel fumarate. The mechanism by which this drug leads to less gastrointestinal effects is purported to be due to its lack of a methanol leaving group in its chemical structure, and substitution with inert 2-hydroxyethyl succinimide
Ditoximel is approved to treat relapsing MS forms, including clinically isolated syndrome, relapsing MS and active secondary progressive MS.
There have been complaints about the costs in the USA, but this is the environment that the US government has allowed to develop. They have allowed the cash cow to develop and MS pharma has created herds of them.