Background: We determined the relative efficacy of subcutaneous (SC) treprostinil in stable World Health Organization class II and III patients transitioned from IV epoprostenol.
Methods: This was an 8-week, multicenter, randomized study in which patients were transitioned from IV epoprostenol to SC treprostinil or placebo over a period of up to 14 days and monitored carefully during and after the transition period for signs of deterioration. Patients with clinical deterioration were returned promptly to epoprostenol. Placebo or SC treprostinil doses were titrated in response to symptoms. Time to adjudicated clinical deterioration was compared between treatment groups, and exercise capacity, symptoms of disease, and safety were assessed throughout the study.
Results: Twenty-two patients were enrolled and completed the study. Seven of 8 patients (88%) [corrected] withdrawn to placebo had clinical deterioration, while only 1 of 14 patients (7%) [corrected] withdrawn to SC treprostinil had clinical deterioration (p = 0.00023 based on a treatment comparison of time to deterioration). Analyses of exercise capacity and symptoms strongly supported the efficacy of SC treprostinil in epoprostenol-treated patients. Adverse events consisted of painful infusion site reactions and anticipated prostacyclin side effects.
Conclusions: SC treprostinil is effective in pulmonary arterial hypertension and prevents clinical deterioration and maintains functional status in patients transitioned from epoprostenol.