The Outcome of Allogeneic Stem Cell Transplantation in Chronic Lymphocytic Leukaemia: A Single Centre 10-Year-Experience

Abstract 4515

Chronic lymphocytic leukemia (CLL) is an incurable disease when treated with standard chemotherapy. The only possibility to provide cure is allogeneic stem cell transplantation (allo-SCT). CLL patients aged less than 55 account for about 15% of patients and these cases allo-SCT should be taken into consideration. The indications for allo-SCT are as follows: del17p, resistance to chemoimmunotherapy, Richter’s syndrome or recurrent disease. A retrospective analysis of allo-SCT in 18 patients (10 males, 8 females) with CLL transplanted in years 2000–2010 was performed. The aim of the study was to assess of long term follow-up outcome of allo-SCT in CLL patients. The median age at diagnosis was 41ys (range: 35–51). The sibling donor was available in 16 cases (2 pts were mismatched), unrelated donors were in 2 cases (1 mismatched). Most of the pts (16 out of 18) were MRD positive when allotransplanted. Median lymphocytosis preceeding allo-SCT was 5.9G/l. Peripheral blood was the source of stem cells in 9 cases (50%), and bone marrow in the remaining 9 cases, 2 pts were transplanted with stem cells from bone marrow and peripheral blood. 4 pts (22%) underwent the allograft procedure twice or more. Reduced intensity conditioning with alemtuzumab was performed in 9 pts (50%), myeloablative regimen in 4 cases and RIC with rituximab in one case.The median number of CD34+cellsx10^6/kg was 4.1 (range: 0.86–9.64). All but one patient engrafted (this pt was transplanted again successfully in one year time). Acute graft-versus host disease (GvHD) was noted in 46% of pts (only in 2 pts grade IV). Extensive GvHD was observed only in 2 pts. Donor lymphocyte infusion (DLI) was performed in 8 pts (44%). With a median follow-up of 73 months (range: 9–89) for surviving patients, the five-year Kaplan-Meier of overall survival (OS) and progression free survival (PFS) was 55,5% and 34%, respectively. At five years, the cumulative probability of non-relapse mortality was 15%. Allogeneic stem cell transplantation remains the effective treatment in CLL for selected group of patients.