Dexpramipexole, also known as (R+) pramipexole, was developed under the name KNS-760704 by Knopp Biosciences (then called Knopp Neurosciences) of Pittsburgh.
Dexpramipexole’s chemical structure is the mirror image of Mirapex, a prescription drug approved for the treatment of Parkinson disease and restless legs syndrome. The structural difference between the two molecules results in significantly different pharmacological effects.
Mirapex, also known as (S-) pramipexole, mimics the actions of a neurotransmitter called dopamine, which would be an undesirable strategy for ALS.
Although its mechanism of action in ALS remains unclear, dexpramipexole has demonstrated neuroprotective properties in multiple studies involving cell cultures and laboratory animals. It may work by improving the function and efficiency of cellular “energy factories” called mitochondria. In ALS, mitochondria endure a cell-damaging process called oxidative stress. It’s suspected that dexpramipexole may help maintain energy production in stressed mitochondria within motor neurons. (See Knopp Neurosciences to Pursue Development of ‘Mirror-Image’ Molecule.)