Preliminary data from rituximab studies alone or in combination with chemotherapy in relapsed or refractory low grade LNH In vitro, rituximab mediates complement dependent cytotoxicity (CDC), antibody dependent cellular cytotoxicity (ADCC) and apoptosis. However, the mechanism of in vivo anti-lymphoma effect remains largely unknown. Rituximab received approval for recurrent follicular lymphoma based on response rates of about 50% including 6% complete responses and duration of responses, which compare favorably to that of all other single agents including fludarabine and 2-CdA (15-19). Median time to progression for responders is around 13 months. Toxicity of rituximab is low and easily manageable. An 8 doses schedule did not show to confer a significant advantage in term of response rate and duration of response over the four doses schedule.