This study is a multicentric randomized trial evaluating the efficacy of the combination ACVBP+rituximab compared to the combination of CHOP+rituximab in patients aged from 18 to 59 years with diffuse large B-cell lymphoma and one factor of the age-adjusted international prognostic index (IPI).

This phase III multicentric open label randomized study is based on the results of previous LNH 93-5 and LNH98-5 studies.

The LNH93-5 study has shown that the ACVBP regimen gave a longer EFS (39% vs 29% at 5 years, p=0.005) and a longer overall survival (46% vs 38% at 5 years, p=0.036) than CHOP in patients aged between 61 and 69 with an IPI score ≥1. However ACVBP had a more important toxicity and a higher treatment related mortality (13% vs 7%, p<0.01), specially after 65 years. In younger patients ACVBP is better tolerated.

The addition of Rituximab to standard CHOP (R-CHOP) has been shown in LNH98-5 study to improve complete remission rate (CR), event-free survival (EFS) and overall survival (OS) in elderly patients with B-DLCL. Considering only patients with an aa-IPI score of 1, the 2 year EFS was 75% in the R-CHOP group as compared with 42% in the CHOP group.

This study is designed to test whether addition of rituximab to ACVBP is better than R-CHOP in patients younger than 60. Primary endpoint is event-free survival, we expect a gain in 2 years-EFS of 10% in R-ACVBP group as compared with R-CHOP group.

This study is a multicentric, phase III open-label, randomized trial evaluating the efficacy of ACVBP+rituximab compared to CHOP+rituximab in patients aged from 18 to 59 years with non previously treated diffuse large B-cell lymphoma and one factor of the age-adjusted international prognostic index

Inclusion Criteria:

Patient with histologically proven CD20+ diffuse large B-cell lymphoma (WHO classification) Aged from 18 to 59 years. Age-adjusted International Prognostic Index equal to 1 (elevated LDH level OR stage III-IV OR ECOG status 2-3-4).

Patient not previously treated. With a minimum life expectancy of 3 months. Negative HIV, HBV and HCV serologies test 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. However, patients not previously diagnosed and having a diffuse large B-cell lymphoma with some small cell infiltration in bone marrow or lymph node may be included.

Central nervous system or meningeal involvement by lymphoma. Contra-indication to any drug contained in the chemotherapy regimens. Any serious active disease (according to the investigator's decision). Poor renal function (creatinin level>150µmol/l), poor hepatic function (total bilirubin level>30mmol/l, transaminases>2.5 maximum normal level) unless these abnormalities are related to the lymphoma.

Poor bone marrow reserve as defined by neutrophils <1.5 G/l or platelets <100 G/l, unless related to bone marrow infiltration.

Any history of cancer during the last 5 years with the exception of non-melanoma skin tumors or stage 0 (in situ) cervical carcinoma.

Treatment with any investigational drug within 30 days before planned first cycle of chemotherapy and during the study.

Pregnant or lactating women. Adult patient under tutelage.