PRX-08066 maleic acid is primarily investigated for its potential therapeutic application in the treatment of pulmonary arterial hypertension (PAH). It acts as a selective 5-HT1B receptor antagonist, helping to modulate serotonin signaling in the pulmonary vasculature. By blocking this receptor, it promotes pulmonary vasodilation, reduces vascular resistance, and may prevent or slow down the progression of vascular remodeling in the lungs.

In preclinical studies, PRX-08066 maleic acid has shown efficacy in improving hemodynamics and lung function in animal models of PAH. Its pharmacological profile suggests potential benefits in improving exercise capacity and delaying disease progression in patients with PAH, particularly when used in combination with existing therapies such as endothelin receptor antagonists or phosphodiesterase-5 inhibitors.

Additionally, due to its action on serotonin pathways, it has been explored for possible off-target effects in conditions involving vascular dysfunction or fibrosis, though its main focus remains in respiratory and cardiovascular therapeutics. The maleic acid salt form enhances solubility and bioavailability, supporting its development as an orally administered agent.