Safety Study of PLX-PAD Cells to Treat Pulmonary Arterial Hypertension (PAH)

Summary of inclusion and exclusion criteria. Eligible subjects: * Are between 18 and 75 years of age * Have a minimum weight of 45 kg * Have a diagnosis of idiopathic or heritable PAH, PAH associated with connective tissue disease (CTD), PAH associated with repaired congenital systemic-to-pulmonary cardiac shunt (at least one year since repair), or PAH associated with appetite suppressant/drug or toxin use confirmed by RHC * Have a current WHO functional class II or III designation * Have been stabilized, without dose changes for at least 30 days prior to the Screening visit on at least two approved PAH medications (e.g., PDE-5 inhibitor, ERA, prostanoid \[as inhalation or infusion\]); or IV prostanoid monotherapy. Subjects on an IV prostanoid must have been receiving therapy for at least three months prior to the Screening visit. * Have a 6MWD equal to or greater than 200 meters (m) at the Screening and Baseline Visits. Subjects must not: * Have any evidence of pulmonary thrombus, significant coronary artery disease (CAD), left ventricular dysfunction, or a restrictive or congestive cardiomyopathy * Have a history of malignancies within the past 5 years,with the exception of individuals with localized, non-metastatic basal cell carcinoma of the skin, in situ carcinoma of the cervix, or prostate cancer who are not currently or expected to undergo radiation therapy, chemotherapy and/or surgical intervention, or to initiate hormonal treatment during the study * Be listed for transplantation * Be pregnant or nursing