Low-Dose Conditioning Followed by Donor Stem Cell Transplant in Treating Patients With Severe Systemic Sclerosis

The purpose of the study is to see how well reduced intensity conditioning followed by a stem cell transplant from a donor (allogeneic) works in treating patients with severe systemic sclerosis. In an allogeneic stem cell transplant procedure, stem cells are taken from a healthy donor and transplanted into the patient. Stem cells can be donated by a family member or an unrelated donor who is a complete tissue type match.

PRIMARY OBJECTIVES: I. To evaluate the overall effects of allogeneic hematopoietic cell transplantation (HCT) in systemic sclerosis (SSc). II. To assess the potential efficacy, in terms of event-free survival (EFS) at 2 (part 1) and 5 (part 2) years, of allogeneic HCT as treatment for patients with severe SSc. SECONDARY OBJECTIVES: I. To evaluate the rate of complications of allogeneic HCT after nonmyeloablative conditioning including the incidence of graft rejection, regimen-related toxicities, severe acute and chronic graft-vs-host disease (GVHD), infectious complications, treatment-related mortality (TRM), and overall survival. II. To evaluate treatment effects on disease activation/progression, as indicated by measures of cardiac, pulmonary, gastrointestinal and renal function, as well as skin thickness, overall functional assessment (SHAQ), use of concomitant disease-modifying antirheumatic drugs (DMARDs), and occurrence of myositis. III. To evaluate disease responses after nonmyeloablative conditioning and allogeneic HCT or immunomodulatory therapy, assessing skin disease by modified Rodnan Skin Score (mRSS), pulmonary function as measured by diffusing capacity of the lung for carbon monoxide (DLCO) and forced vital capacity (FVC), Modified Scleroderma Health Assessment Questionnaire (SHAQ), and Quality of Life using Short Form 36 (SF36). IV. To evaluate, by mechanistic studies, of the effect of allogeneic HCT on dermal fibrosis and vasculopathy. V. To evaluate the late complications of allogeneic HCT after nonmyeloablative conditioning including the incidence and prevalence of chronic GVHD and time to discontinue immunosuppression, infectious complications, TRM and overall survival. VI. To evaluate the treatment effects on disease activation/ progression, as indicated by measures of cardiac, pulmonary, gastrointestinal and renal function, as well as skin thickness, overall functional assessment (SHAQ), use of concomitant DMARDs, and occurrence of myositis. VII. To evaluate disease responses after nonmyeloablative conditioning and allogeneic HCT or immunomodulatory therapy, assessing skin disease by modified Rodnan Skin Score (mRSS), pulmonary function as measured by DLCO and FVC, Modified Scleroderma Health Assessment Questionnaire (SHAQ), and Quality of Life using Short Form 36 (SF36). OUTLINE: Patients are assigned to 1 of 2 treatment arms and receive nonmyeloablative conditioning followed by an allogeneic peripheral blood stem cell transplantation. Treatment in both arms continues in the absence of disease progression of unacceptable toxicity. ARM I (transplant): Patients receive fludarabine intravenously (IV) on days -4 to -2. Patients undergo total-body irradiation on day 0. Patients then undergo peripheral blood stem cell transplantation on day 0. Patients receive GVHD prophylaxis comprising tacrolimus orally (PO) twice daily on days -3 to 180 and taper and mycophenolate mofetil PO three times daily on days 0-28 and then twice daily until day 180 and taper. ARM II (nontransplant): Patients will receive immunosuppressive therapy based on their history. The 3 options that they may receive include 1.)mycophenolate mofetil PO twice daily for 16 months, 2.) Rituximab IV on days 1 and 15 and then repeated at 6 months, and 3.) Cyclophosphamide IV at 28-32 day intervals or orally once daily for 16 months. After completion of study treatment, patients are followed up periodically for 5 years.