Patient Characteristics and Treatment Patterns with Macitentan in Pulmonary Arterial Hypertension: Insights from the OPUS Registry

Purpose To describe the real-world use and safety profile of macitentan in patients with pulmonary arterial hypertension (PAH) enrolled in the OPsumit® USers registry (OPUS; NCT02126943). Methods OPUS is an ongoing long-term, prospective, multicenter, observational drug registry of patients newly treated with macitentan in the USA. Patient characteristics, treatment patterns, safety of macitentan and survival were analyzed for PAH patients. Results As of April 2018, OPUS included 1455 PAH patients with follow-up data. At enrollment, median (range) age was 62 (13-92) years and 75.2% were female. The median (Q1, Q3) time from PAH diagnosis was 6.2 (1.5, 37.0) months. WHO functional class (FC) was assessed in 1062 patients, 39.3% were in FC I/II and 60.7% in FC III/IV; median (Q1, Q3) 6-minute walk distance, assessed in 620 patients, was 305 (206, 383) meters. Use of macitentan in double or triple combination therapy regimens is shown in the Table. Median (Q1, Q3) exposure to macitentan was 11.6 (3.9, 22.2) months and macitentan was discontinued by 28.7% of patients, with adverse events (AEs) as the most common reason. At least 1 AE was experienced by 1076 (74.0%) patients; the most common were dyspnea (18.2%), headache (9.5%) and peripheral edema (8.8%). In total, 485 (33.3%) patients experienced ≥1 hospitalization. The Kaplan-Meier survival estimates (95% CI) were 91% (90, 93) at 12 months and 84% (82, 87) at 24 months. Conclusion OPUS represents the largest cohort of patients newly treated with macitentan, providing insight into macitentan use in the real-world. These analyses show that macitentan is most commonly initiated as monotherapy or in combination with a phosphodiesterase type 5 inhibitor in PAH. The safety profile of macitentan in OPUS is consistent with that observed in clinical trials.