Autologous or allogeneic stem cell transplantation versus chemotherapy in acute myeloid leukemia and subgroups: A multicenter trial by the German AML Cooperative Group

Abstract

6556 Background: From the data available the role of autologous and allogeneic stem cell transplantation (auto/allo SCT) versus post-remission chemotherapy appears uncertain and is readdressed in the present trial. Methods: Pts were stratified for cytogenetic groups, de-novo/secondary AML, LDH, WBC, and were up-front randomized in one step to induction by HAM-HAM vs TAD-HAM, and to G-CSF priming vs. no G-CSF. These two randomizations did not result in different outcome. Pts were also upfront randomized to auto SCT vs monthly maintenance chemotherapy. Within the two randomized arms pts with histocompatible family donors underwent priority allo SCT. Results: Since 1999 840 pts 16–60 y of age entered the trial. 14%, 62%, 21%, and 3% of pts had favorable, intermediate, unfavorable and unknown karyotype, and 19% had secondary AML. 70% of pts went into complete remission (CR). The probability of overall survival (OS) at 3 years in the auto SCT and the maintenance arm is 43% vs 41% (p=0.52), the relapse-free survival (RFS) is 40% vs 40% (p=0.78), and the ongoing remission duration (RD) is 48% vs 46% (p=0.65). Among pts alive and in CR 73% did receive auto SCT or maintenance or allo SCT, similar to previous trials (NEJM 332:217,1995, Blood 90:2978,1997, Lancet 351:700,1998, NEJM 339:1649,1998). The outcome according to therapy given in the auto SCT arm and the maintenance arm shows ongoing RD of 44% vs 50% (p=0.31), RFS of 44% vs 48% (p=0.35), and OS of 53% vs 69% (p=0.005). 128 pts underwent allo SCT. In a matched pair analysis with concordance of pairs in karyotype, de-novo/secondary AML, induction chemotherapy, and RFS at the time of SCT, RD shows a superiority of allo SCT (p<0.001), while OS is similar between the two arms (p=0.65). No prognostic subgroup with a special benefit from auto or allo SCT can be identified so far. Conclusions: Among current alternative strategies only novel approaches in allo SCT reducing the high transplant related death rate may further improve the cure of pts with AML and subgroups. No significant financial relationships to disclose.