Scleroderma: Cyclophosphamide or Transplantation (SCOT)

This prospective, randomized, open-label, multi-center, 2-arm, Phase II clinical trial will randomize approximately 114 subjects with severe SSc in the United States and Canada. Subjects will be randomly assigned in a 1:1 ratio to a treatment of high-dose immunosuppressive therapy with autologous stem cell rescue (HDIT transplantation) or to treatment of monthly pulse IV cyclophosphamide. Subjects will be stratified by treatment center. The initial treatment period will be approximately 3 months for the HDIT transplantation arm (from the time of initiation of mobilization until the day of transplant) and 12 months for the cyclophosphamide arm. Subjects will be followed for up to 72 months after randomization. The study will continue for 54 months after the last subject is randomized.