Reduced Intensity Conditioning (RIC) Allogeneic Stem Cell Transplantation (allo-SCT) in Patients with Haematological Lymphoid Malignancies: Long Term Follow-up in a Single Centre Series.

Patients (pts) with recurrent and refractory haematological lymphoid malignancy (HLM) have a very limited survival expectance. RIC allo-SCT has been proposed as a strategy for retaining the graft versus malignancy effect of allo-SCT while decreasing transplant related mortality (TRM). Here, we retrospectively studied a series of 32 pts treated by RIC allo-SCT.

Between April 2001 and November 2007, 32 pts with HLM underwent RIC allo-SCT with an HLA-identical sibling donor. Fifteen pts with multiple myeloma, 7 pts with Non-Hodgkin lymphoma, 6 pts with Chronic lymphoid leukaemia, 3 pts with Hodgkin lymphoma and 1 pt with Waldenstrom disease. At time of allo-SCT, 10 pts were in complete remission (3 received prior autologous transplant) and 22 in refractory/progressive disease (6 received prior autologous transplant). Median age was 38 years (range, 28-60) and the sex-ratio (M/F) 2,2. Median time from diagnosis to RIC allo-SCT was 18 (range,6-76) months. The conditioning regimen included Fludarabine 150mg/m² and Melphalan 140mg/m². GVHD prophylaxis consisted of association cyclosporine (cSA) and mycophenolate (MMF). All pts received G-CSF mobilised peripheral blood stem cells, with a median CD34+ cell count: 6,2.10⁶/kg (range, 1.9-13,6).

Neutropenia occurred in all pts (100%) and the median duration of aplasia was 9 (range, 5-16) days. Only 10 pts (31 %) required red blood cells transfusions and 23 pts (71 %) needed platelets transfusions. Acute GVHD was observed in 15 cases (47 %) including 10 cases of grade II-IV. Fifteen pts (75 %) had chronic GVHD, of whom 9 with an extensive form. Four pts (12 %) had CMV reactivation at a median time 60 (range, 52-80) days after transplantation. Six pts (18 %) had late onset relapse at a median time of 13 (range, 4-45) months. TRM was 43 % at one year after RIC allo-SCT. With a median follow-up of 60 (range 18-97) months, 12 pts (37,5 %) are still alive in complete remission with full donor chimerism. Twenty pts (62,5 %) have died (5 early severe infections, 10 GVHD, 3 after relapse, one myocardial infarction, and one accident). Overall and progression-free survivals at 8 years are 31 % and 30 % respectively.

This study, after a large follow-up, suggests that RIC allo-SCT is a potential therapy for refractory or progressive HLM. However, TRM is still high likely due to the inclusion of refractory and heavily pretreated pts with many comorbid conditions.

No relevant conflicts of interest to declare.