Patients receive 6-8 cycles of A-CHOP followed by 8 cycles of maintenance bevacizumab (MA), as outlined below. Bevacizumab 15 mg/kg is administered on day 1 over 90 min (first cycle), 60 min (second cycle) and 30 min for the subsequent cycles. CHOP (cyclophosphamide 750 mg/m 2 ; doxorubicin 50 mg/m 2 ; vincristine 1.4 mg/m2 [max. 2 mg]; prednisone 100 mg daily on days 1-5) is administered on day 1 of a 21-day cycle. Radiographic response is assessed after cycles 3, 6 and 8 of ACHOP and after cycle 8 of MA. Patients receive six cycles of ACHOP if they achieve a complete response (CR) after three cycles, eight cycles if they achieve a partial response (PR) after three cycles. Non-responders are removed from the study. ACHOP responders receive maintenance bevacizumab 15 mg/kg every 21 days for eight cycles.