Selexipag, a selective prostacyclin receptor agonist in pulmonary arterial hypertension: a pharmacology review

INTRODUCTION: Pulmonary hypertension is defined by a mean pulmonary artery pressure ≥25 mm Hg at rest. Management of pulmonary arterial hypertension (PAH) includes specific drug therapy with calcium channel blockers in vasoreactive patients, or drugs approved for PAH in non-reactive patients that target the endothelin, nitric-oxide and prostacyclin pathways. Areas covered: The review covers receptor selectivity, pharmacokinetics, pharmacodynamics and adverse effects (AEs) of intravenous (IV) epoprostenol (synthetic prostacyclin); the prostacyclin analogs iloprost, beraprost, and treprostinil administered by IV, subcutaneous, inhaled or oral routes; and the oral selective prostacyclin receptor agonist selexipag. Expert commentary: Development of a selective prostacyclin receptor agonist has aimed at identifying compounds with improved pharmacological properties. The high selectivity of selexipag, and its active metabolite ACT-333679, for the prostacyclin receptor, in conjunction with pharmacokinetic properties that reduce peak-trough fluctuations and the up-titration regimen used at the start of treatment, are collectively considered to minimize AEs associated with prostacyclin use. In a large phase 3 study, selexipag-associated AEs were consistent with those observed with drugs that target the prostacyclin pathway, and mainly mild to moderate in severity. The dosing flexibility afforded by oral selexipag may facilitate achieving the maximum therapeutic effect with acceptable tolerability in patients with PAH.