Primary refractory AML is associated with an extremely poor prognosis [1,2]. In the AMLHD93 trial conducted by the AMLSG ULM, patients refractory to the first induction therapy with ICE (idarubicin, cytarabine, etoposide) had an overall survival of 12% after 5 years [1]. All patients alive in this cohort had received allogeneic transplantation. Therefore, we assigned allogeneic transplantation in our consecutive trial, AMLHD98A, to all primary refractory patients [3]. However, the main problem in this patient group remains achieving a partial (PR) or complete (CR) remission to a salvage therapy. Additionally, the pre-transplant disease status is an important prognostic factor in most studies of allogeneic transplantation, regardless dose intensified or dose reduced conditioning regimens are used [4,5,6]. Since 1993, in all studies of the German-Austrian-AMLSG response-adapted treatment strategies had been used. Within the AMLHD93 trial, refractory patients were assigned to an intensified second induction regimen with S-HAM (age<55 years) [7] or HAM (age 55 to 60 years) [1], and in the AMLHD98A trial, with A-HAM [3]. The incorporation of all-trans-retinoic acid was based on in vitro data [8-13] and by our randomised AMLHD98B study for elderly AML-patients showing a benefit in primary response and survival for patients assigned to standard induction therapy in combination with ATRA [14].