- Arm A: Patients receive FOLFIRI chemotherapy comprising irinotecan hydrochloride IV over 90 minutes and leucovorin calcium IV over 2 hours on day 1 and fluorouracil IV over 46 hours on days 1-2. Chemotherapy treatment repeats every 2 weeks for 12 courses. Patients also receive bevacizumab IV over 30-90 minutes once every 2 weeks during chemotherapy. Patients then receive bevacizumab maintenance therapy once every 2 weeks during the chemotherapy-free interval.