PH-501

PH-501 is an orally administered small molecule phosphodiesterase type 5 (PDE5) inhibitor being developed for the treatment of pulmonary arterial hypertension (PAH). Developed by Original Drug Port (Shanghai) Pharmaceutical, the compound targets the PDE5 enzyme to prevent the degradation of cyclic guanosine monophosphate (cGMP) in pulmonary vascular smooth muscle cells. Increased cGMP levels facilitate vasodilation and inhibit the proliferation of smooth muscle cells, thereby reducing pulmonary arterial pressure and improving exercise capacity. PH-501 is currently being evaluated in a Phase Ib/II clinical trial (CTR20252910) in China to determine its safety, pharmacokinetics, and preliminary efficacy in patients with PAH.