Patient and disease characteristics of the first 500 patients with pulmonary arterial hypertension treated with selexipag in real-world settings from SPHERE

BACKGROUND: Selexipag is a selective oral prostacyclin receptor agonist indicated for pulmonary arterial hypertension (PAH) treatment. SelexiPag: tHe usErs dRug rEgistry (SPHERE) (NCT03278002) is collecting data from selexipag-treated patients in real-world clinical practice to elucidate and describe the clinical characteristics, outcomes, and dosing/titration regimens of patients treated with selexipag in routine clinical practice. METHODS: SPHERE is a United States (US)-based, ongoing, multicenter, prospective observational study (target N = 800). This study enrolls patients who are either newly initiated on selexipag (≤60 days before enrollment) or were previously receiving selexipag with documentation of dose titration at study enrollment. Data collection for the study occurs at routine clinic visits. In this paper, we report on the first 500 patients enrolled. RESULTS: Median follow-up was 17.8 months; 77.6% of patients completed the planned 18 months follow-up, and 22.4% discontinued early from the study. At diagnosis, 94.8% of patients had PAH (World Health Organization [WHO] Group 1), most commonly idiopathic (49.2%) and connective tissue disease associated (26.4%). Most patients (72.4%) initiated selexipag more than 60 days before enrollment. At initiation, 31.0% of patients had WHO functional class (FC) II disease, and 49.6% had WHO FC II or III disease. In addition, 55.0% of patients were receiving double therapy (most commonly an endothelin receptor antagonist plus phosphodiesterase type 5 inhibitor [42.3%]), whereas 30.6% were receiving monotherapy. Despite most patients already receiving PAH-specific therapy, at selexipag initiation, 67.2% (336 of 500) were at intermediate risk, and 9.6% (48 of 500) were at high risk of 1-year mortality. Risk scores remained stable in ∼55% of patients and improved in ∼20% at the end of the study. In total, 72.2% of patients had at least 1 adverse event (AE), and 37.6% reported a serious AE. The median selexipag maintenance dose was 1,200 µg twice daily (interquartile range: 800–1,600 µg twice daily). CONCLUSIONS: Real-world, US-based patients with PAH initiating selexipag typically have WHO FC II/III disease and are at intermediate risk, despite receiving PAH-specific treatment. Selexipag was prescribed as part of a combination regimen in most patients. The study identified no unexpected adverse effects.