Evaluation of the efficacy of a single injection of Pegfilgrastim (6mg) administered at day 3 of each cycle of R-ACVBP regimen during 4 cycles in patients with CD20+ diffuse large B-cell lymphoma presenting at least 2 adverse prognostic factor of the age-adjusted international prognostic index (Aa-IPI).

This is a phase II, multicentric, open-label, non-randomized study, evaluating the efficacy of a single injection of Pegfilgrastim (6mg) administered at day 3 of each cycle of R-ACVBP regimen during 4 cycles in patients aged 18 to 60 years with previously untreated CD20+ diffuse large B-cell lymphoma presenting at least 2 adverse prognostic factor of the age-adjusted international prognostic index (Aa-IPI), and eligible for transplant.

It is anticipated that 60 subjects will be enrolled over 2 years (from 2004 to 2006), in a group sequential manner one planned interim analysis.

The duration of the treatment period is approximately 26 weeks and patients are followed until Death.

The total Duration of the study is expected to be 2.5 years.

Inclusion Criteria:

• Patient with histologically proven CD20+ diffuse large B cell lymphoma (WHO Classification).
• Age >18 and < 61 years, eligible for transplant.
• Patient not previously treated.
• With at least two prognostic factors of the Aa-IPI.
• With a minimum life expectancy of 3 months.
• Creatinin level ≤ 150mmol/l, total bilirubin level 30mmol/l and transaminases 2.5 maximum normal level, unless abnormalities are related to the lymphoma.
• Neutrophils > 1.5 G/l and platelets > 100 G/l, unless if patient has a bone marrow infiltration.
• Negative HIV, HBV and HCV serologies 4 weeks (except after vaccination).
• Having previously signed a written informed consent.

Exclusion Criteria:

• Any other histological type of lymphoma.
• Any history of treated or non-treated indolent lymphoma.
• Central nervous system or meningeal involvement by lymphoma.
• Contra-indication to any drug contained in the chemotherapy regimens.
• Any history of cancer during the last 5 years, with the exception of non-melanoma skin tumors or stage 0 (in situ) cervical carcinoma.
• Any serious active disease (according to the investigator's decision).
• Treatment with any investigational drug within 30 days before planned first cycle of chemotherapy and during the study.
• Pregnant or lactating women or women of childbearing potential not currently practicing an adequate method of contraception.
• Adult patient under tutelage.