PB2467: ALLOGENEIC HEMATOPOIETIC STEM CELL TRANSPLANTATION IN 39 PATIENTS WITH NON-HODGKIN LYMPHOMA: LONG-TERM FOLLOW-UP IN A SINGLE CENTRE

Topic: 22. Stem cell transplantation - Clinical Background: Non-Hodgkin’s lymphomas (NHL) represent a heterogeneous group of malignant proliferations of lymphoid cells (B or T) with very different prognosis from one form to another. Allogeneic hematopoietic stem cell transplantation (allo-HSCT) currently represents the only potentially curable treatment for all type of NHL in a setting of relapse/refractory disease Aims: We report a retrospective single-centre study a series of 39 patients (pts) who underwent this procedure in our center. Methods: Between December 2000 and June 2019, 39 pts with NHL underwent allo-SCT (geno-identical: 38 pts, haplo-identical: 1 pt) in our center with various type of NHL (DLBCL: 14; Burkitt lymphoma: 6; Lymphoblastic lymphoma: 6; mantle cell lymphomas: 2; peripheral T-cell lymphoma: 6 and other lymphomas: 5). The median age of the pts is 30 years (7-59), the sex ratio is 1,2 (22M/17F). Median time from diagnosis to allo-HSCT was 23 months (5-86). At time of allo-SCT, 27 pts (69,2%) were in complete remission (CR), 10 pts (25,6%) in partial remission (PR) and 2 pts (5,1%) in refractory/progressive disease. Eight pts received prior autologous transplant. Myeloablative conditioning regimen (MAC) busulfan-based was provided to 29 pts (74,3%) and reduced intensity conditioning (RIC) associated fludarabine-melphalan with or without ATG in 10 pts (25,6%). Graft versus host disease (GVHD) prophylaxis consisted of Cyclosporin and Methotrexate (MAC), Cyclosporin and Mycophenolate mofetil (RIC). A peripheral blood stem cell (PBSC) graft was used in all pts, with a median CD34+ cell count: 6,7.106/kg (1.2-13,6) except one pt who received an unmanipulated bone marrow (BM) transplant and PBSC (haplo-identical). Results: Aplasia was observed in all pts with median duration of 12 days (6-19). The median day of neutrophils engraftment was 13 days (6-21). No patient developed either transplant associated micro-angiopathy (TAM), veino-occlusive disease (VOD) or haemorrhagic cystitis. Acute GVHD grade II-IV occurred in 14 pts (35,8%) on average at day 30 (16-78). Chronic GVHD was seen in 17 pts (60%) with extensive form in 11 pts on average at day 270. Eleven pts (28,2%) showed CMV reactivation. Six pts (15,3%) relapsed, of which 4 pts were in PR or progressive disease at the time of transplant. At December 2022, after a median follow-up of 148 months (42-254), 16 pts (41%) are alive and 23 pts (59%) died within 18 pts (46,1%) from TRM (GVHD: 9, severe infection: 6, pulmonary embolism: 1 and secondary malignancy: 2) and 5 from relapse (12,8%) and the overall survival (OS) and disease free survival (DFS) are 34,6% and 34,6% respectively. Summary/Conclusion: Allo-HSCT offers the potential of curative treatment on the basis of the GVL effect in young and fit pts with NHL, as shown in this study with very long-term follow-up. This is probably valid in resource-limited setting without availability of new targeted and cellular-therapies Keywords: Allogeneic hematopoietic stem cell transplant, Non-Hodgkin’s lymphoma