Evaluation of LIQ861 Inhalation Powder Deposition and Pharmacokinetics

Inhaled prostacyclin (PGI) therapies offer significant important clinical benefits to patients with Pulmonary Arterial Hypertension (PAH), compared to other PGI delivery routes. Current approved PGI inhaled therapies are delivered using nebulization, which can present a treatment burden on patients. For instance, Tyvaso® (treprostinil inhalation solution, United Therapeutics, Silver Spring, MD) uses a pulsed, ultrasonic nebulizer delivering approximately 6 mcg of treprostinil per breath, with a target maintenance dose of nine breaths (54 mcg of treprostinil), four times daily. Furthermore, this product requires dose preparation and daily cleaning of the nebulizer [1]. To address some of these shortcomings, Liquidia Technologies (Research Triangle Park, USA) is developing LIQ861, an inhaled, dry-powder formulation which is currently in Phase 3 development [2]. LIQ861 is designed for efficient, deep-lung delivery using a convenient, disposable dry powder inhaler (DPI), for delivery of treprostinil doses in 1–2 breaths, four times daily. The pharmacokinetic data (PK) and lung deposition of LIQ861 inhalation powder in nonclinical, in silico, and clinical studies are presented in this study.