Compound 18a

Compound 18a is a selective, small-molecule adenosine A2A receptor antagonist developed by Biogen (formerly Biogen Idec) for the potential treatment of Parkinson's disease. It belongs to a chemical series of bicyclic piperazine derivatives, specifically triazolotriazine and triazolopyrimidine analogues. As a non-dopaminergic therapeutic agent, Compound 18a is designed to modulate neurotransmission within the basal ganglia, a region of the brain heavily involved in motor control that is affected in Parkinson's disease. By blocking A2A receptors, the compound aims to improve motor symptoms without the complications associated with traditional dopaminergic therapies. Preclinical studies demonstrated that Compound 18a possesses high affinity for the A2A receptor and exhibits significant oral efficacy in rodent models of catalepsy, which are used to simulate the motor deficits of Parkinson's disease.