AUTOLOGOUS PERIPHERAL-BLOOD STEM-CELL TRANSPLANTATION (PBSCT) MOBILIZED WITH G-CSF IN AML IN FIRST COMPLETE REMISSION - ROLE OF INTENSIFICATION THERAPY IN OUTCOME

In order to determine if peripheral blood stem cells (PBSC) collected after priming with G-CSF in AML in first complete remission (CR) can b e used for autologous transplantation and to evaluate the efficacy of early intensification therapy as in vivo purging, we studied 35 consec utive patients with AML in first CR, After standard induction and cons olidation chemotherapy, 24 of them were treated with one (10 patients) or two (14 patients) cycles of high-dose cytarabine plus etoposide pr ior to PBSC collection, G-CSF was used as the priming agent, Of the 35 patients scheduled for peripheral blood stem cell transplantation (PB SCT), three relapsed before transplantation, and the 32 remaining unde rwent PBSCT, High-dose therapy consisted of either total body irradiat ion plus cyclophosphamide or busulphan plus cyclophosphamide, The medi an number of CD34(+) cells infused was 3.24 x 10(6)/kg (range 0.15-14) , The median times to reach a PMN count of 0.5 x 10(9)/l and a platele t count of 50 x 10(9)/l were 12 (8-28) and 30 (11-345) days, respectiv ely, There was no transplant-related mortality, Twelve patients relaps ed between 2 and 21 months post-PBSCT, With a median follow-up of 28 m onths, actuarial disease-free survival (DFS) is 52.41 +/- 9% in the in tent-to-treat group and 57.4 +/- 9.8% in patients who underwent PBSCT. The probability of DFS is significantly higher for patients who recei ve early intensification therapy prior to both PBSC collection and PBS CT as compared with patients that do not: 68.8 +/- 10.27% vs 35.5 +/- 12.6%, P = 0.0418, These results indicate the feasibility of PBSCT in AML using G-CSF-mobilized PBSC, The use of intensification treatment a s 'purging in vivo' prior both to collection of PBSC and PBSCT signifi cantly reduces the risk of relapse in this group of patients.