Treatment of Acute Promyelocytic Leukemia With All-Trans Retinoic Acid (ATRA) and Idarubicin (AIDA)

The purpose of this study is to evaluate the efficacy of all-trans retinoic acid (ATRA) and idarubicin (AIDA) with a dose reduction in patients older than 70 years of age in the remission induction of acute promyelocytic leukemia (APL). With regard to the induction, the excellent results obtained by the combination of ATRA and idarubicin (AIDA), especially in terms of antileukemic efficacy (1% of resistance), do not support the introduction of substantial changes in this combination. However, given that most of the induction failures were caused by complications, especially of a hemorrhagic nature, and that these had a major impact in the hyperleukocytic forms and in patients older than 70 years of age, the induction was modified as follows: 1. Reduction of idarubicin dose in patients older than 70 years of age (three days instead of four); 2. Early administration of corticosteroid therapy in all patients as ATRA syndrome prophylaxis. A preliminary analysis of the Italian Group for Adult Hematologic Diseases (Gruppo Italiano Malattie Ematologiche dell'Adulto, GIMEMA) has shown that low dose prednisone use in a prophylactic manner appears to reduce the incidence and severity of the ATRA syndrome, which could also have a favorable impact on the hemorrhagic mortality (non-published data); and 3. Treatment of the hyperfibrinolysis with an antifibrinolytic agent (tranexamic acid). It has been recently reported that APL cells present abnormally high levels of annexins (especially annexin II), and that these levels may provide the fundamental mechanism for the hemorrhagic complications in APL by increasing the production of t-PA dependent plasmin. These findings provide new reasons for the introduction of tranexamic acid in the hemorrhagic prophylaxis of APL.