Primary Rituximab and Maintenance

* Objectives * Primary objective: To evaluate in patients with advanced follicular lymphoma the benefit of maintenance therapy with rituximab after induction of response with chemotherapy plus rituximab in comparison with no maintenance therapy * Secondary objective: To evaluate response rates, event driven survival endpoints (EFS, PFS, OS) and quality of life of four different chemotherapy regimens combined with rituximab, with or without maintenance with rituximab, for first line treatment of advanced stage follicular lymphoma. * Study Design This is an international open-label, multicentre, randomized study with two treatment phases. In the induction phase patients have to respond to 1st line induction treatment in order to be eligible for randomization to the second phase of maintenance treatment or observation. After the maintenance period patients will be included in the follow up phase for 3 years.

Study medication * First period: Induction of response with 8 x rituximab combined with 8 cycles of CVP or 6 cycles of CHOP in 21-day cycles or 6 cycles of FCM in 28-day cycles or 6 cycles of MCP in 28-day cycles. * Second period: rituximab 375 mg/m2 every 8 weeks for 24 months (12 injections) or control with no treatment