Study of a New Thermo Stable Formulation of Epoprostenol Sodium to Treat Pulmonary Arterial Hypertension (PAH)

This is a multicentre, open label, single-arm study in approximately 20 adult patients (18 - 75 years old) designed to evaluate the Impact on lifestyle of a new thermo stable formulation of epoprostenol sodium in subjects with Pulmonary Arterial Hypertension (PAH). The co-primary objectives are 1) to describe the effect of the new thermo stable formulation of epoprostenol sodium on quality of life and 2) to determine the dose titration requirement in patients switching from the currently marketed FLOLAN (epoprostenol sodium) to the new thermo stable formulation. Secondary objectives include assessing the safety, tolerability and efficacy of the thermo stable formulation of epoprostenol sodium and the exploratory objective is to evaluate the effect of the new thermo stable formulation of epoprostenol sodium on haemodynamic parameters in a subset of subjects. Subjects who are already receiving FLOLAN (epoprostenol sodium) for the treatment of PAH and have been on a stable dose for at least 3 months and on stable doses of other PAH treatments for at least 30 days prior to screening will be enrolled. After a screening visit, eligible subjects will have a 4-week run-in period with their existing FLOLAN (epoprostenol sodium) treatment. At the end of the 4-week period, they will be admitted to the clinic for baseline assessments and for switching to study medication (the new thermo stable formulation of epoprostenol sodium). Subjects will remain in hospital for a minimum of 6 hours to ensure clinical and hemodynamic stability prior to discharge. Subjects may stay in hospital for up to 24-48 hours after switching to the new thermo stable formulation of epoprostenol sodium at the discretion of the investigator. Dose titration requirement will be assessed at the time of discharge. Haemodynamic parameters will be obtained in a subgroup of subjects enrolled in centres where the collection of haemodynamic data is considered part of the standard of care. Subjects will receive the study medication as a continuous intravenous infusion for a 4-week treatment period. Those who complete the 4-week treatment period will have the option of entering an extension phase of the study to continue receiving the new formulation.