Continuous Alloreactive T Cell Depletion and Regulatory T Cell Expansion for the Treatment of Steroid-refractory or Dependent Chronic GVHD

Inclusion Criteria: (Main) * 1\. Newly diagnosed chronic GVHD as defined by the National Institutes of Health (NIH) Consensus with no more than 24 weeks of treatment with systemic steroids. AND 2. Chronic GVHD must be refractory or dependent to standard therapy, defined as (one of the following): * Progression on prednisone 7 mg/kg/week for 2 weeks, or * Stable disease on ≥ 3.5 mg/kg/week of prednisone for 4-8 weeks, or * Inability to taper prednisone below 3.5 mg/kg/week. Exclusion Criteria: (Main) * 1\. Persistent, recurrent or late-onset acute GVHD, without signs of chronic GVHD. OR 2. Overlap GVHD syndrome with uncontrolled features of previously diagnosed acute GVHD. OR 3. Treatment with more than two systemic non-steroidal immunosuppressants within 4 weeks prior to enrollment. OR 4. Time from allogeneic transplantation \> 2 years. OR 5. Lymphocyte count \< 0.2 x 109/L on two last consecutive CBCs before inclusion