On January 3, 2018, Liquidia Technologies announced the initiation of a Phase III clinical trial evaluating LIQ861 (inhaled treprostinil) for the treatment of pulmonary arterial hypertension (PAH).
LIQ861 is a powder formulation of treprostinil that is designed for deep-lung delivery using a dry powder inhaler (DPI). It utilises Liquidia’s PRINT technology, which combines a proprietary particle moulding technology with a modular, roll-to-roll manufacturing process to deliver scalable processes that meet cGMP requirements.
According to Liquidia, the benefits of their technology include applying precise particle design to overcome specific pharmacologic or therapeutic challenges and reduce costs and save time with highly repeatable and efficient particle fabrication processes.
Pulmonary arterial hypertension
PAH is a rare, fatal cardiopulmonary disease that is a subset (Group 1) within the WHO’s classification of the different types of pulmonary hypertension. The disease is characterised by an abnormal rise in the resting mean pulmonary artery pressure (PAP) (>25mmHg compared with normal levels of around 14mmHg), a pulmonary vascular resistance of more than 3 Wood Units, and a pulmonary capillary wedge pressure less than 15mmHg. The increased PAP is caused by pulmonary arterial obstruction and increased resistance due to endothelial dysfunction and vascular remodelling.
Since PAH is a progressive disorder, the pulmonary pressure builds up as the patient advances through the later stages of the disease, leading to reduced cardiac output, right heart failure, and ultimately death.
Although there is no cure, there are several different classes of drugs used for treatment of PAH, which include endothelin receptor antagonists (ERAs), phosphodiesterase type 5 (PDE5) inhibitors, soluble guanylate cyclase stimulators, prostacyclin derivatives, and prostacyclin IP receptor agonists.
According to key opinion leaders (KOLs) interviewed by GlobalData, the current drugs that stimulate the prostacyclin pathway are either too burdensome for patients, resulting in low compliance rates, or lack sufficient efficacy.
Treprostinil is a synthetic analogue of prostacyclin that acts as a vasodilator for the treatment of PAH.
The currently marketed formulations of treprostinil have all been developed by United Therapeutics: Remodulin, which is available in a subcutaneous formulation as well as an intravenous formulation; Tyvaso, which is an inhaled formulation; and Orenitram, which is an oral formulation.
KOLs interviewed by GlobalData from both the US and the 5EU strongly feel that the oral and inhaled versions of treprostinil that are currently available are not efficacious and will not replace current PAH treatments.
Since LIQ861 is a powder formulation of treprostinil for inhalation, it will be imperative for Liquidia Technologies to demonstrate significant superior efficacy results of LIQ861 compared to a widely used prostacyclin derivative, such as epoprostenol, iloprost, or currently marketed treprostinil formulations, if they expect to capture significant patient market share.
Liquidia’s Phase III trial is expected to enrol at least 100 US PAH patients. The primary endpoints are long-term safety and tolerability of LIQ861, with topline data expected in 2019.
GlobalData (2017). OpportunityAnalyzer: Pulmonary Arterial Hypertension – Opportunity Analysis and Forecasts to 2026, October 2017, GDHC076POA
GlobalData (2016). OpportunityAnalyzer: Pulmonary Arterial Hypertension – Opportunity Analysis and Forecasts to 2024, January 2016, GDHC050POA