A Study to Evaluate the Efficacy of an Oral Medication in the Treatment and Prevention of Digital Ulcers in Patients With Systemic Sclerosis (Scleroderma).

Inclusion Criteria:

   - Diagnosis of limited or diffuse systemic sclerosis (SSc) according to American College
   of Rheumatology or LeRoy criteria

   - Age greater than 18 years of age

   - At least one digital ulcer located on the volar or lateral surface at or distal to the
   proximal interphalangeal joints

   - At least one new DU that developed within 12 weeks prior to screening

   - Vasodilator therapies, including calcium channel blockers, alpha-1-antagonists,
   ACE-inhibitors, nitroglycerin, and angiotensin receptor blockers, are permitted as
   long as the doses are stable for 2 weeks prior to screening and throughout the study

   - Treatment with omeprazole or other proton pump inhibitors must be stable for 2 weeks
   prior to screening and throughout the study

Exclusion Criteria:

   - Patients with pulmonary arterial hypertension, NYHA Class III or IV

   - Patients who are hemodynamically unstable, or have acute renal, cardiac or pulmonary
   failure

   - Concurrent malignancy except non-melanoma skin cancers

   - Patients who have required systemic antibiotics for infected digital ulcers within 2
   weeks of screening

   - Patients receiving phosphodiesterase-5 inhibitors, endothelin receptor antagonists, or
   prostanoids within 4 weeks of screening

   - Patients receiving cyclosporine within 6 weeks of screening

   - Patients who have participated in any investigational study within 30 days of
   screening

   - Pregnant or nursing women

   - Patients with a history of drug or alcohol abuse within 6 months of screening

   - History of hepatitis B, hepatitis C, or HIV infection

   - Any medical condition that, in the opinion of the investigator, might interfere with
   the subject's participation in the study or poses an added risk for the subject

   - Inability to comply with study and follow-up procedures

   - Transaminase elevation > 3X the upper limit of normal at screening

   - Hemoglobin less than 8.5 g/dL

   - Platelet count less than 100 X 109/L

   - White blood cell count less than 3.0 X 109/L

   - Serum creatinine less than 2.0 mg/dL