6528 Background: Rituximab monotherapy has shown a high activity in relapsed follicular lymphomas. Recently, phase III studies indicated that its addition to chemotherapy may further improve the progression-free survival substantially. Methods: In 1998 the GLSG embarked on a multicenter national trial in patients with relapsed or refractory follicular and mantle cell lymphoma. As most patients had received CHOP for first line treatment, a fludarabine-containing regimen (FCM) was chosen for salvage therapy followed by an optional Rituximab maintenance. A total of 4 courses were given. After the statistical analysis confirmed the significantly improved response rate of the combined study arm (R-FCM), 111 subsequent patients were designated to immuno-chemotherapy. Results: 122 of 244 currently evaluable patients (50%) had follicular, 95 patients (39%) mantle cell and 24 patients (10%) other indolent lymphomas. In 67 randomized patients with follicular lymphoma, complete (39% vs. 23%, p=0.013) as well as over...