The Purpose of this study is to evaluate the efficacy and the safety of R-GEMOX in refractory/relapsed patients with CD20-positive large B-cell lymphoma who are not eligible for autologous transplantation.

This is a multicentric, open-label, non-randomized clinical study, evaluating the efficacy and the safety of R-GEMOX in refractory/relapsed patients aged from 18 to 75 years with CD20-positive large B-cell lymphoma non eligible for autologous transplantation.

It is anticipated that 50 subjects will be enrolled over 4 years (from April 2003/January 2007), but inclusion could stop earlier according to the analysis performed every 5 patients (based on triangular test).

The duration of the treatment period is approximately 16 weeks and patients are followed until death.

The total duration of the study is expected to be 3 years.

Inclusion Criteria:

• Patients diagnosed with histologically or cytologically proven, CD 20+, diffuse large B-cell lymphoma,
• Relapse after first or second CR, PR or less than PR to first-line treatment for the rituximab-naïve patients, OR relapse after first or second CR with a minimum delay of 12 months between the last rituximab infusion and the inclusion for the rituximab-experienced patients
• Aged 18 - 75 years
• Not eligible for autologous transplantation
• Previously treated with chemotherapy containing anthracycline, with or without rituximab
• ECOG performance status 0 to 2
• With a minimum life expectancy of 3 months
• Having signed informed consent form prior to enrollment

Exclusion Criteria:

• Burkitt's, mantle cell, T-cell lymphomas
• CD 20-negative lymphoma
• HIV or HBV related disease
• Central nervous system or meningeal involvement by the lymphoma
• Not previously treated with anthracycline-containing regimens
• Contraindication to any drug contained in the R-GEMOX chemotherapy regimen
• Any serious active disease or co-morbid medical condition (according to the investigator's decision),
• Poor renal function (creatinine level > 150micromol/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
• Any radiotherapy during the four weeks before inclusion
• Pregnant or lactating woman
• Adult patient unable to give informed consent because of intellectual impairment.