Preladenant was investigated primarily for the treatment of Parkinson’s disease. It functions as an adenosine A2A receptor antagonist, which helps modulate motor control in the central nervous system. By blocking these receptors, Preladenant aimed to improve motor function and reduce the symptoms of Parkinson’s, especially motor fluctuations caused by long-term use of levodopa. It was studied as an adjunct therapy to enhance the effectiveness of existing Parkinson’s medications, with the goal of reducing "off" periods when symptoms are poorly controlled. Although clinical development was discontinued due to lack of sufficient efficacy in later-stage trials, it contributed to research on non-dopaminergic approaches for managing Parkinson’s disease.