Real-world treatment practices of selexipag and parenteral prostacyclin (PGI2) analogs for pulmonary arterial hypertension in Japan: Retrospective study of the Japan PH Registry

Background In treatment of pulmonary arterial hypertension (PAH), the prostacyclin (PGI 2 ) pathway is targeted by oral selexipag and parenteral PGI 2 analogs. Although guidelines recommend therapeutic strategies based on disease severity and etiology, there are limited data on real-world use of selexipag and parenteral PGI 2 analogs in Japan. This study aimed to characterize the use of these drugs in treatment of PAH in Japan, with a focus on differences related to patient characteristics and PAH etiology. Methods Patients with PAH registered in the Japan PH Registry (JAPHR) from November 2016 to March 2023 were evaluated. Patients who met the inclusion criteria were further stratified by PAH etiologies, drug used, severity of disease, treatment strategies, time from diagnosis to drug initiation, and pulmonary hemodynamics. Results A total of 235 patients were treated with selexipag and 121 patients with parenteral PGI 2 . Selexipag and parenteral PGI 2 analogs were most frequently used for idiopathic PAH (IPAH) or heritable PAH (HPAH), at 56.2 % (132/235) and 82.6 % (100/121), respectively. Selexipag was also used more frequently than parenteral PGI 2 analogs for PAH associated with connective tissue disease and congenital heart disease. Most patients received triple therapy, with 76.2 % (179/235) and 59.5 % (72/121) receiving selexipag and parenteral PGI 2 analogs, respectively. Regarding New York Heart Association functional class (NYHA-FC), selexipag was primarily administered to Class II–III patients and parenteral PGI 2 analogs to Class III patients. Both mean pulmonary artery pressure and pulmonary vascular resistance values were lower in the selexipag group than in the parenteral PGI 2 group. Conclusion Parenteral PGI 2 analogs tend to be used mainly in patients with severe IPAH/HPAH, while selexipag is used in patients with a broader range of etiologies around NYHA-FC II–III. Choice of selexipag and parenteral PGI 2 analogs for treatment of PAH is influenced by disease severity and etiology.