Inclusion Criteria:

Target Population

• meet ACR criteria for scleroderma
• have clinical evidence of active skin disease with a skin score of ≥15
• have had the onset of their first non-Raynaud phenomenon feature of SSc no more than 3 years prior to screening
• have evidence of fibrosing alveolitis (active pulmonary fibrosis) manifested by a FVC between 45% and 80% of predicted normal and/or DLCO between 30% and 70% of predicted normal values
• have an abnormal high resolution CT scan of the chest/lungs demonstrating typical ground glass changes of alveolitis with background fibrosis
• have adequate renal function- no evidence of renal crisis in the 2 months prior to enrollment and serum creatinine < 3 mg/dL
• for both sexes, must use an acceptable form of birth control
• age ≥ 18

Exclusion Criteria:

• Clinically significant pleural or pericardial effusion in the previous 12 months: Grade 3 or 4. Patients with recent Grade I or II effusions or peripheral edema will be permitted to enter the study
• Clinically significant cardiac disease (New York Heart Association Class III or IV) including preexisting arrhythmia, (such as ventricular tachycardia, ventricular fibrillation, or "Torsade de Pointes"), myocardial infarction, uncontrolled angina within 6 months, congestive heart failure, cardiomyopathy, or pericardial disease
• Clinically-significant coagulation or platelet function disorder (eg, known von Willebrand's disease)
• Abnormal QTcF interval prolonged (> 450 msec) after electrolytes have been corrected on baseline ECG

Laboratory Test Findings

• Hgb < 10 g/dL; platelet count < 100,000/dL; WBC < 3,000/dL; PMN < 1,000/dL; OR lymphocytes < 350/dL
• The presence of any of the following laboratory findings at screening: positive for antibodies to hepatitis C virus; positive for antibodies to hepatitis B surface antigen (HBsAg); serum bilirubin 2 times normal, ALT or AST > 2.5 times upper limit of normal

Prohibited Treatments and/or Therapies

• use of other immunosuppressive therapies must be discontinued at enrollment, eg methotrexate, azathioprine, cyclophosphamide, mycophenolic acid, mycophenolate mofetil, cyclosporine
• treatment with any other experimental or investigational drug(s) concurrently or less than 12 weeks prior to study enrollment
• use of anti-fibrotic agents must be discontinued at enrollment, eg colchicine, D‑penicillamine, minocycline or Type 1 oral collagen