Allogeneic Transplant in Patients with Poor Prognosis B-Chronic Lymphocytic Leukemia (B-CLL): Comparative Study between Myeloablative(M) and Non-Myeloablative(NM) Conditioning Regimen.

Sustained complete remissions (CR) have been reached with allogeneic transplant in patients with poor prognosis B-CLL; however, mortality rates are high (20–50%); in order to reduced TRM, NM conditioning are widely used in haematological malignancies; however it is not clear if the use of NM regimens can maintain the efficacy reducing the toxicity. IN this report we performed a retrospective comparison between 30 patients (group A) who have received myeloablative conditioning consisted of TBI plus Cy in 23 pts (74%), TBI, Cy plus VP-16 in 6 pts (19%) and BuCy in 1 patient and 31 patients (Group B) who have received a NM transplant. Conditioning regimens in Group B included: Fludarabine plus Melphalan, 20 pts (64%), Fludarabine, Busulphan and ATG, 5 pts (16%), Fludarabine, TBI and ATG, 4 pts (13%) and Fludarabine plus TBI, 1 patient. All patients received peripheral blood stem cells from a HLA related identical donor. T-cell depletion was performed in 14 patients of the group A. Median age at transplant was significantly higher in the group B patients (53 versus 45, respectively) (p<0,005); no differences were observed in terms of status at transplant and n° of previous chemotherapy lines as well in the risk of graft versus host disease (GVHD) and transplant related mortality (TRM) (See Table, below).

With a median follow-up of 71 and 36 months for groups A and B respectively,Overall Survival and Event Free Survival are similar for both groups (53% versus 64% and 60% versus 68%, respectively). Although patients in the NM transplant group were older toxicity was similar in both groups; moreover a similar efficacy has been observed suggesting the clear role of graft versus tumour effect in B-CLL probably more important that the type ofconditining.

Table 1