This is a Phase 2, multicenter, double-blind, randomized, placebo-controlled study to evaluate the effect of iloprost on the symptomatic relief of Raynaud's Phenomenon attacks in subjects with symptomatic Raynaud's Phenomenon secondary to Systemic Sclerosis.

Inclusion Criteria:

• Male or female subjects must be greater than or equal to 18 years of age
• Subjects must have a diagnosis of Systemic Sclerosis
• Subjects must have a diagnosis or history of Raynaud's Phenomenon
• Subjects must have a minimum of 10 symptomatic Raynaud's Phenomenon attacks
• Female subjects of childbearing potential and male subjects must agree to use contraception for the duration of the study
• Subjects must be willing and able to comply with the study requirements and give informed consent for participation in the study

Exclusion Criteria:

• Female subjects who are pregnant or breastfeeding
• Subjects with systolic blood pressure <85 mmHg
• Subjects with an estimated glomerular filtration rate <30 mL/min/1.73 m2
• Subjects with Child-Pugh Class B or Class C liver disease or an alanine aminotransferase and/or aspartate aminotransferase value >3 × the upper limit of normal at screening.
• Subjects with gangrene, digital ulcer infection, or requirement of cervical or digital sympathectomy
• Subjects with intractable diarrhea or vomiting
• Subjects with a risk of clinically significant bleeding events including those with coagulation or platelet disorders
• Subjects with a history of major trauma or hemorrhage
• Subjects with clinically significant chronic intermittent bleeding such as active gastric antral vascular ectasia or active peptic ulcer disease
• Subjects who have had any cerebrovascular events
• Subjects with a history of myocardial infarction or unstable angina within 6 months of screening
• Subjects with acute or chronic congestive heart failure
• Subjects with a history of life-threatening cardiac arrhythmias
• Subjects with a history of hemodynamically significant aortic or mitral valve disease
• Subjects with more than mild restrictive or congestive cardiomyopathy uncontrolled by medication or implanted device.
• Subjects with known pulmonary hypertension, pulmonary arterial hypertension, or pulmonary veno-occlusive disease
• Subjects with a history of significant restrictive lung disease defined as forced vital capacity <45% predicted and diffusing capacity of the lungs for carbon monoxide <40% predicted (uncorrected for hemoglobin).
• Subjects with a history of cervical or digital sympathectomy
• Subjects with scleroderma renal crisis
• Subjects with a concomitant life-threatening disease with a life expectancy <12 months
• Subjects who have a clinically significant disorder, that in the opinion of the Investigator, could contraindicate the administration of study drug, affect compliance, interfere with study evaluations, or confound the interpretation of study results
• Subjects who have taken or are currently taking any parenteral, inhaled, or oral prostacyclin or prostacyclin receptor agonists
• Subjects must not initiate dosing of oral, topical, or intravenous (IV) vasodilators or if currently receiving any vasodilator must have been stably medicated
• Subjects with any history of acetaminophen intolerability
• Subjects with any malignancy that requires treatment during the study period, that has required treatment within 1 year of screening, or that is currently not in remission.
• Subjects who have used any investigational medication or device for any indication within 30 days or 5 half-lives (whichever is longer)