PB1673 FEASIBILITY AND OUTCOME OF ALLOGENEIC BONE MARROW TRANSPLANTATION IN ADULT PHI NEGATIVE ACUTE LYMPHOBLASTIC LEUKEMIA

Background:Acute lymphoblastic leukemia (ALL) is a rare disease in adults. Despite the novels therapies, clinical outcomes remain unsatisfactory. Bone marrow allograft still holds its place as a consolidation treatment for patients in complete remission in order to improve the prognosis and lengthen survival.Aims:We study in this work the feasibility and outcome of bone marrow allograft for adult Philadelphia chromosome negative ALL.Methods:Our study is retrospective including the cases of high‐risk adult ALL (HR) diagnosed in the hematology department of Hédi Chaker Hospital of Sfax during the period from January 2004 to December 2015. These patients were treated according to protocols inspired by GRAALL 2003 and 2005. The indication of bone marrow allograft is systematic in patients whose age are <50 years and having a compatible intrafamilial donor. For our patients we studied the allograft indication, the search for a family compatible HLA donor, the feasibility of the allograft and finally the result of this one which was carried out at the national center of bone marrow transplantation in Tunis.Results:Among the 36 cases of adult phi negative ALL treated with the GRAALL 2003 and 2005 protocols, 28 patients were in complete remission (CR) and 22 patients (79%) were classified as HR. Twenty patients had indication of bone marrow allograft (2 were> 50 years of age). Of the 20 patients who had an HLA study, 14 patients (70%) had a compatible HLA family donor. Allogeneic bone marrow allograft could only be performed for 9 patients: 64% of patients with a compatible HLA donor and 45% of patients with CR. For the 5 others the transplant could not be done for: relapsed before allograft for 2 cases and severe comorbidities for the 3 others. The median time to completion of the allograft was 15 weeks. Among the allografts, 6 patients (67%) were living in CR after a follow‐up of 74 months, one patient relapsed at 6 months post‐transplant and 2 patients died of acute GVH. Of the 19 non‐allograft CR patients, 6 patients were living in CR (31%) and 1 died during consolidation therapy and 12 relapsed. The 5‐year DFS of both allografted and non‐allografted patients was 72% and 21%, respectively.Summary/Conclusion:Despite the cost‐effectiveness of the intra‐familial HLA study (70% donor) in our study, allografting could only be performed for a small number of patients (45%), hence the need to expand the indication of allograft for subjects over 50 years old or perform a mini allograft, do the same haplo transplant and even expand donor sources on files (pheno‐identical donors). Two‐thirds of the allografted patients in our series did not relapse, an interesting result and comparable to the literature.