The primary objective of the protocol is to estimate the complete response rate of three courses of the association of rituximab, navelbine, ifosfamide, mitoxantrone, and prednisone in relapsed aggressive non hodgkin's B-cell lymphoma

Phase II study of the efficacy and toxicity of rituximab, navelbine, ifosfamide, mitoxantrone, and prednisone in relapsed aggressive non hodgkin's B-cell lymphoma.

The study intervention is an administration of 3 courses of the abovementioned drugs, witch doses are detailed below. Remission is assessed and the investigator is free to proceed with any kind of consolidation , he decides best for the patient( high dose or standard chemotherapy).

The addition of Rituximab the the NIMP protocol is warranted on the basis of previous publications wtich have shown a significant advantage in addition to chemotherapy in complete remission rate and in overall survival.

Navelbine has shown an interesting activity in lymphoma relapse. Mitoxantrone has a good toxicity profile for patients who have prevously received anthracyclines, and there is not so much cross resistance between the two drugs.

Ifosfamide is commonly used in the treatment of relapsed and refractory lymphoma, because of its low hematologic toxicity profile and good antitumor activity.

Inclusion Criteria:

• Both genders, between 18 and 75 years old
• CD 20+ large cell lymphoma
• In first relapse
• No previous autologous stem cell transplantation or relapsing more than 12 months after an autologous stem cell transplantation
• Ann Arbor stage I, II, III ou IV
• ECOG 0,1 or 2
• Signed informed consent

Exclusion Criteria:

• age: before 18 and more than 75 years old
• other type of lymphoma
• Informed consent not signed