Schematic description of transplantation approach. A high-risk group of elderly patients underwent matched-sibling transplantation and received a CD25-allodepleted lymphocyte product (SD) together with a purified stem-cell product following reduced-intensity conditioning with fludarabine (125-180 mg/m2) and cyclophosphamide (120 mg/kg) or melphalan (140 mg/m2) or infusional busulfan (6.4 mg/kg). Both products were infused at day 0. Patients received cyclosporine alone for GvHD prophylaxis starting on day − 5. In the absence of aGvHD, immunosuppression was tapered off by day + 100. The SD product was obtained after treatment of a 72-hour coculture of patient-derived, expanded, irradiated T cells and donor-derived lymphocytes with an anti-CD25 immunotoxin. Flu indicates fludarabine; mel, melphalan; bu, busulfan; and Cy, cyclophosphamide.
