About APD811APD811, an orally bioavailable agonist of the prostacyclin receptor, is an investigational drug candidate discovered by Arena and intended for the treatment of PAH. Prostacyclin receptor agonists slow disease progression and improve exercise tolerance in PAH patients and are among the treatments administered as standard of care for advanced PAH. Currently available prostacyclin receptor agonists belong to the prostanoid class of molecules, and these products need to be administered frequently or continuously through intravenous, subcutaneous or inhaled delivery methods. Arena believes that an orally bioavailable, non-prostanoid prostacyclin receptor agonist that provides clinical benefits similar to currently available prostacyclin receptor agonists has the potential to improve the standard of care for PAH.