Abstract • 183

Chemotherapy of primary ANLL is intensive and may include an allogeneic or autologous stem cell infusion (SCI). Still about 50% of the patients will relapse. Treatment results of these patients are dismal and their tolerance for further chemotherapy is limited. Therefore, alternative novel treatment options should be investigated such as: 1) phase II cytostatic drugs like cladribine (2-CDA), fludarabine, liposomal daunorubicin; 2) combinations of cytostatic drugs with multi drug resistance reversing agents like cyclosporin; 3) growth factors to increase chemosensitivity of the leukemic cells or to ameliorate myelosuppression; 4) immunotherapy with donor lymphocyte infusions (after allogeneic SCI), with interleukin 2 (IL-2), or cytotoxic antibodies; 5) after achieving second complete remission a (second) allogeneic SCI from the same or an other donor (matched unrelated or haplo-identical); 6) differentiation enhancers like all-transretinoic acid (ATRA) and butyric acid derivatives. Obviously, these investigational approaches should be used only within a collaborative study. The protocol should allow for the heterogeneity of the relapse ANLL patients. Treatment of relapse ANLL patients not registered on a study protocol is not in the patient's best interest and may be considered unethical.