Survival After Post-Hematopoietic Stem Cell Transplantation Aml Relapse: A Single Center Experience

Introduction Post-allogeneic hematopoietic stem cell transplantation (HSCT) acute myeloid leukemia (AML) relapse has a dismal prognosis and no standard of care treatment. Current common treatment options for (re)inducing a graft versus leukemia effect (GvL) are cessation of immunosuppressive therapy, administering hypomethylating agents or high dose chemotherapy. After reinduction of remission is achieved, the effect can be consolidated with a donor lymphocyte infusion (DLI) or a second allogeneic HSCT. In this study we analyzed outcomes of patients with post-allogeneic HSCT AML relapse in our institute. Objectives To evaluate outcome of patients with post-allogeneic HSCT AML relapse, who received different types of reinduction therapy regimens and of whom a subgroup underwent immunological consolidation therapy. Methods Data was collected from the medical history of all 83 adult patients that had received an allogeneic stem cell transplantation for AML or high-risk myelodysplastic syndrome (MDS) at the Amsterdam University Medical Centers between January 1st 2010 and 31st December 2016 and who relapsed before December 31st 2017. In this retrospective analysis, patients were divided into a curative intent treatment group and a palliative care group. Statistical analysis was done with IBM SPSS version 24.0.0.1 using Mann-Whitney U, Chi-square testing, Pearsonu0027s R for ordinal variables and Kaplan Meier survival analysis with log rank testing. Results 50 (60%) of the 83 patients were treated with the intent to cure and the other 33 (40%) received palliative care. Of the patients treated with curative intent, 13 (26%) survived. The patients in the palliative care group were older than the patients in the curative intent group (median age 58 vs 53 year, P =0.043). They also had a higher bone marrow blasts count (median 37.5% vs 20.5%, P =0.025), and shorter time between allo HSCT and relapse (median 21 weeks with IQR of 6-28 vs median of 21 weeks with IQR 14-47.25, P =0.047). Within the curative intent group these variables did not differ significantly between survivors and deceased. Of the patients in the curative intent group 44% reached CR and of these patients 50% survived. The majority of the survivors received high dose cytarabine treatment (69%) and immunologic consolidation therapy (69%). A relapse ≤ 12 weeks after allogeneic HSCT but not relapse P =0.292 vs P =0.007). Conclusion This retrospective analysis of a real-life, non-preselected patient group with post-allogeneic HSCT AML or MDS relapse demonstrated that patients who were fit enough to receive high-dose reinduction therapy, followed by a immunologic consolidation with DLI or a second allogeneic HSCT had the best chance to obtain durable remissions, in particular when immunologic consolidation was performed when the patient had obtained complete remission.