Dexpramipexole is the (D)-enantiomer of pramipexole. Enantiopure dexpramipexole has essentially no dopamine agonist activity and shares no other pharmacologic similarity to pramipexole. In contrast, pramipexole the (S)-enantiomer is a dopamine agonist and is an approved drug (Mirapex) used in Parkinson’s disease.
Dexpramipexole is a low molecular weight, orally bioavailable, water-soluble small molecule with linear pharmacokinetics and linear dose proportionality.