Istradefylline, or KW6002, was developed by Kyowa Hakko Kirin in Japan for the treatment of Parkinson’s disease as an adjunct to standard therapy.2 Unlike standard dopaminergic therapies for Parkinson’s, Istradefylline targets adenosine A2A receptors in the basal ganglia.2 This region of the brain is highly involved in motor control.2

Istradefylline is indicated as an adjunct treatment to levodopa and carbidopa for Parkinson’s  disease.8

This drug was first approved in Japan on 25 March 2013.2 Istradefylline was granted FDA approval on 27 August 2019.5

Istradefylline is a selective adenosine A2A receptor inhibitor.1,2 These receptors are found in the basal ganglia, a region of the brain that suffers degeneration in Parkinson’s disease, and is also significantly involved in motor control.2 A2A receptors are also expressed on GABAergic medium spiny neurons within the indirect striato-pallidal pathway.7 The GABAergic action of this pathway is thereby reduced.7 Istradefylline has 56 times the affinity for A2A receptors than A1 receptors.2