Selexipag is an oral prostacyclin IP receptor agonist that is structurally unique from prostacyclin. It is converted to the active form of the drug in the liver, which is 37 times more potent than the parent molecule, and binds directly to a receptor called the IP receptor. Selexipag and its metabolite bind to the IP receptor but not to other types of prostacyclin receptors.
In The GRIPHON study, which enrolled 1,156 patients with PAH (idiopathic PAH, heritable PAH, PAH associated with corrected-congenital shunts, PAH associated with connective tissue disease, PAH associated with drug or toxin exposure, and HIV-associated PAH), treatment with selexipag resulted in a 40% risk reduction in the composite endpoint of death or a complication related to PAH, mainly due to patients experiencing a hospitalization or a pre-defined sign of disease progression. This significant beneficial effect was seen in patients who were not yet on treatment for PAH when enrolled in the trial as well as in patients who were already on another medication, i.e., background therapy (phosphodiesterase inhibitor and/or endothelin receptor antagonist).
