8012 Background: Rituximab has been evaluated as a single agent and also in combination with chemotherapy in aggressive and indolent lymphomas with evidence of efficacy. More recently, rituximab maintenance therapy has been successfully used to keep responding patients in remission. We have shown that consolidative HDC improves outcome of poor risk responder-patients (pts) with aggressive lymphoma. Methods: The aim of the present study was to evaluate the potential benefit, as randomly compared to observation, rituximab - 375 mg/m2/week for 4 weeks - 2 months after HDC, in decreasing the relapse rate (second randomization: R2). A secondary objective was to improve the response rate before HDC using the intensified ACE chemotherapy regimen (doxorubicin 75mg/m2 d1, cyclophosphamide 1g/m2 d1-d2, etoposide 150mg/m2 d1-d3) as compared to the standard ACVBP induction regimen (R1). Four cycles were delivered every 15 days. In responding pts, HDC (mitoxantrone 45 mg/m2, cyclophosphamide 1500 mg/m2 × 4d, etoposide...