ALLOGENEIC BLOOD-CELL TRANSPLANTATION WITHOUT POSTTRANSPLANT COLONY-STIMULATING FACTORS IN PATIENTS WITH HEMATOPOIETIC NEOPLASM - A PHASE-II STUDY

Purpose: There is limited experience with allogeneic blood cell transp lantation (BCT). In an earlier pilot study, the combination of bone ma rrow and blood did not produce severe acute graft-versus-host disease (GVHD). We now report the results of a phase II study using blood stem cells alone in 19 patients. Patients and Methods: The median age was 40 years. All patients had hematopoietic malignancies and received tra nsplants from HLA-identical sibling donors. GVHD prophylaxis consisted of cyclosporine plus prednisone. Posttransplant colony-stimulating fa ctors were not administered. Donors were mobilized with subcutaneous g ranulocyte colony-stimulating factor (G-CSF; 16 mu g/kg/d) for 5 days. Apheresis was performed on 2 consecutive days. Results: The median ce ll content of the two apheresis was 11.9 x 10(8) WBC/kg, 3.2 x 10(8) C D3/kg, and 8.3 x 10(6) CD34/kg. The median rime to achieve an absolute neutrophil count (ANC) greater than or equal to 500/mu L was 13 days, and 14 days to a platelet count greater than or equal to 50,000/mu L. All patients engrafted. Platelet recovery was faster than in marrow h istoric control groups. Blood cells in all tested cases contained more than 95% donor cells on day 30. The actuarial incidence of acute GVHD was 37%, and 13% for grade II-IV GVHD. Limited, corticosteroid respon sive, chronic GVHD developed in 33% of assessable patients. At a media n follow-up of 192 days, actuarial survival was 75%. Conclusion: Trans plantation of a high number of stem cells may lead to rapid engraftmen t without the use of posttransplant colony-stimulating factors. GVHD d oes not appear to be more severe than in similarly treated patients un dergoing bone marrow transplantation. For allogeneic transplantation, mobilized blood cell collections are on alternative to bone marrow col lections. (C) 1996 by American Society of Clinical Oncology.