According to amendment 3 this study addresses the question if intensification of administration of rituximab in standard treatment for patients with newly diagnosed aggressive B-Non Hodgkin Lymphoma (B-NHL) and high risk (aaIPI 2 or 3) results in a better time to treatment failure (TTTF)

This study was primarily designed to compare aggressive conventional chemotherapy with a repetitive high-dose (HD) therapy program using identical, effective drugs at highest possible dose and dose intensity with/without addition of rituximab (initially 4 treatment arms). In 2004 the first amendment had to be added in order to close two treatment arms without rituximab due to recent data revealing a significant advantage for rituximab-treated patients with CD20+lymphoma.

A planned interim analysis in 2010 revealed inferiority of the high-dose treatment thus in the 2nd amendment the high-dose arm was closed and additionally the rituximab frequency was raised from 6 to 12 administrations as recent publications gave hint for advantage. The last amendment was added in 2010 to adjust for delayed recruitment mainly due to organisation problems.

As the high-dose arm was closed only CD20+ B-lymphoma were included past amendment 2.

Inclusion Criteria:

• 18-60 years of age
• Risk group International Prognostic Index (IPI) 2 and 3 (age adjusted)
• Performance status: Eastern Cooperative Oncology Group (ECOG) 0-3
• Patient's written informed consent
• Aggressive non-Hodgkin's lymphoma with CD20+ histology

Exclusion Criteria:

• Already initiated lymphoma therapy
• Serious accompanying disorder or impaired organ function
• Bone marrow involvement > 25%
• Known hypersensibility to the medications to be used
• Known HIV-positivity
• Active hepatitis infection
• Suspicion that patient compliance will be poor
• Simultaneous participation in other trials
• Prior chemo- or radiotherapy for previous disorder
• Other concomitant tumour disease