This is an open-label, multicenter, parallel, randomized (1:1 Slow Dose Titration Group;
Rapid Dose Titration Group), two-group study to evaluate the safety, tolerability,
pharmacokinetics and efficacy of slow and rapid dose titration regimens of subcutaneous
Remodulin infusion in subjects with pulmonary arterial hypertension (PAH). The study will
include about 50 subjects at up to 10 clinical trial centers in China. The treatment phase of
the study will last approximately 16 weeks. Subjects who complete all required assessments
will also be eligible to enter a long-term open-label, extension study (CVT-CV-004).