Rapid achievement of complete donor chimerism and low regimen-related toxicity after reduced conditioning with fludarabine, carmustine, melphalan andallogeneic transplantation

Between August 1998 and July 1999, 21 patients received a novel protocol of reduced conditioning with fludarabine, carmustine and melphalan (FBM) foll owed by matched-related allogeneic peripheral blood stem cell transplantati on (PBSCT) in a prospective multicenter phase I/II study. Cyclosporin A and 'mini-methotrexate' were used for GVHD prophylaxis. Patients were included because of age, advanced disease, previous transplantation or co-morbidity , Hematopoietic engraftment after allogeneic transplantation was rapid with a median white blood count (WBC) >1 x 10(9)/l on day +11 (range 10-17) and a median platelet count >20 x 10(9)/l on day +13 (range 9-36), Donor chime rism was complete in 16/21 (76%) patients at all time points during follow- up and mixed at least on one occasion in 5/21 (24%) patients. The condition ing regimen was well tolerated with low toxicity even in previously transpl anted patients. Thirteen patients (62%) developed acute GVHD grades II-IV, Nineteen out of 21 patients achieved complete (CR, n = 15) or partial remis sion (PR, n = 4),vith a median patient follow-up of 354+ days (range 258-57 7) for patients alive, The reduced intensity protocol FBM is feasible with rapid engraftment, early achievement of complete donor chimerism, low toxic ity, especially in heavily pretreated patients, and good response rates in advanced disease patients.