Comparing and Combining Bortezomib and Mycophenolate in SSc Pulmonary Fibrosis

Systemic sclerosis (SSc) is a chronic multisystem autoimmune connective tissue disease for which the etiology remains unknown. The prevalence for SSc is between 19-75 cases per 100,000 and it is more frequent in women, with a peak occurrence in the 4th or 5th decade of life. Morbidity and Mortality in SSc are substantial and pulmonary complications are now the leading cause of death among patients with SSc. Bortezomib is an FDA approved therapy for the treatment of multiple myeloma and other malignancies. The investigators have data that bortezomib inhibits transforming growth factor (TGF) - signaling in vitro and promotes normal repair and prevents against lung fibrosis in the TGF-mediated intratracheal bleomycin mouse model as well as in a mouse model for skin fibrosis. This is consistent with other data in the literature that proteasomal inhibition can prevent the development of fibrosis. Further there are multiple reports on the efficacy of bortezomib in ameliorating chronic graft-versus-host disease in patients after allogeneic hematopoietic stem cell transplant for multiple myeloma. Bortezomib was also well tolerated in the large clinical trials of multiple myeloma patients with neuropathy and thrombocytopenia the primary adverse events. No pulmonary toxicities were reported in these studies. Mycophenolate mofetil (CellCept or Myfortic) belongs to a class of medications known as immunosuppressives. This medication was used originally in the management of patients with organ transplants, but is now recommended in the treatment of some autoimmune diseases such as SSc. Mycophenolate mofetil targets an enzyme in the body called inosine monophosphate dehydrogenase that is important for the formation of deoxyribonucleic acid (DNA) in cells. By interfering with DNA, the medication impairs function of immune system cells that become overactive in autoimmune diseases. Mycophenolate mofetil is currently approved in the treatment of patients with SSc. This study is being conducted to establish the safety and tolerability of bortezomib in SSc patients at high risk for pulmonary disease progression. In addition, the study will examine the effect of bortezomib on the rate of forced vital capacity (FVC) decline (a physiologic parameter closely associated with disease outcome) and other clinical parameters. In addition the investigators will also measure the effect of bortezomib on biomarkers associated with fibroblast activation. If successful, the study will provide the rationale for a multi-center placebo controlled trial to test the efficacy of bortezomib in SSc patients at high risk for progressive pulmonary disease.