BREEZE Optional Extension Phase: Long-term safety and efficacy of treprostinil dry powder inhaler (Tyvaso DPI) in pulmonary arterial hypertension

Introduction: Pulmonary arterial hypertension (PAH) is a rare and progressive disease associated with significant morbidity and mortality. Prostacyclins, including treprostinil, are a mainstay of PAH treatment, particularly in patients with intermediate to high risk of death. Following the approval of treprostinil inhalation solution for PAH, treprostinil dry powder inhaler (DPI) was developed as a small, portable, low-maintenance device to improve patient experience. Objective: The primary objective of the BREEZE study was to assess the safety and tolerability of treprostinil DPI in PAH. Methods: BREEZE was a 3-week, single-arm, open-label study in which patients with PAH transitioned from a stable dose of treprostinil inhalation solution to a comparable dose of treprostinil DPI. Results: Following the 3-week treatment phase, 49 of 51 patients opted to enroll in the Optional Extension Phase (OEP). Throughout the OEP, 6MWD continued to increase with a median change from baseline of 16 m at week 107 and over a third of patients experiencing an improvement of at least 30 m. Patient satisfaction with the DPI device was overwhelmingly positive while drug-related adverse events were infrequent and characteristic of prostacyclin therapy. Conclusion: The BREEZE OEP successfully demonstrated the safety of long-term treatment with treprostinil DPI in patients with PAH. Clinical trial registration: NCT03950739.