The combination of ATRA and anthracycline based chemotherapy (CT) is established as the reference treatment of newly diagnosed APL. For CT, recent reports have suggested than an anthracycline alone may be as effective as anthracycline-AraC combinations, while being less myelosuppressive. We tried to confirm this hypothesis in a randomized trial. Patients and methods: In APL 2000 trial (started in July 2000) newly diagnosed APL patients (pts) 10,000/mm3 (Group C) received the same treatment as Group A, but with AraC 2 g/m2/12h x4d during the second consolidation course. Pts aged > 60 with WBC 10,000/mm3 (Group E) received the same treatment as Group B and Group A, respectively. All pts with WBC > 10,000/mm3 received intrathecal MTX +AraC for CNS prophylaxis. Results: the first interim analysis was made at the reference date of September 1st 2003, after inclusion of 300 patients. Overall 289 (96.3 %) patients achieved CR, 9 (3 %) had early death (ED) and 2 had resistant leukemia. 19 patients relapsed, including 15 hematological relapses (Hem Rel) and 4 purely molecular relapses (Mol Rel) (ie treated before Hem rel). The randomized groups (pts 10 000 WBC, n = 70), 98 %, 11%, 79.4%, and 90.3% for Group D (> 60 years 60 years, > 10 000 WBC, n = 16). Conclusion: Our results strongly support that, at least with the anthracycline used (DNR at a cumulative dose of 495mg/m2) AraC should not be omitted in consolidation chemotherapy of newly diagnosed APL, even in patients with WBC 10 000/mm3 supports a role for high dose AraC (1 to 2 g/m2/12h) in this population at higher risk of relapse. Following this first interim analysis, Groups B and D (ie groups without AraC) were closed for inclusion. Updated results will be presented.