A Dose Escalation Study to Evaluate the Effect of RT234 in Subjects With Pulmonary Arterial Hypertension

Inclusion Criteria

• •1. Between 18 and 80 years of age, inclusive.
• •2. Diagnosis of RHC-confirmed WHO Group 1 PAH in any of the following three categories: Idiopathic, primary or familial pulmonary arterial hypertension (IPAH, PPH, or FPAH); OR PAH associated with one of the following connective tissue diseases (CTD):
• •1. Systemic sclerosis (scleroderma)
• •2. Limited scleroderma
• •3. Mixed connective tissue disease
• •4. Systemic lupus erythematosus
• •5. Overlap syndrome
• •6. Other autoimmune disorders;
• •OR PAH associated with:
• •1. Human immunodeficiency virus (HIV) infection with no evidence of opportunistic infection in the preceding 6 months;
• •2. Simple, congenital systemic-to-pulmonary shunts at least one-year post-surgical repair.
• •3. Exposure to legal drugs, chemicals and toxins, such as fenfluramine, derivatives, other anorexigens, toxic rapeseed oil or L-tryptophan. Subjects with PAH associated with illegal drug use, such as methamphetamine, were excluded.
• •3. Previous diagnosis with PAH with the following conditions:
• •1. Stable PAH without significant adjustments of disease-specific background PAH therapy, at least 3 months prior to RHC procedure;
• •2. If on corticosteroids, has been receiving a stable dose of ≤ 20 mg/day of prednisone (or equivalent dose of other corticosteroid) for at least 30 days prior to RHC procedure.
• •4. Pulmonary Function Tests within 24 months prior to RHC procedure that fulfilled the following criteria (pulmonary function; (PFT may be assessed at Screening if historical PFT results are not available):
• •1. Forced Expiratory volume in one second (FEV1) ≥ 60% predicted (pre-bronchodilators);
• •2. FEV1/ forced expiratory vital capacity (FVC) ≥ 60% (pre-bronchodilators);
• •3. FVC ≥ 60% predicted.