3528 Background. Bevacizumab (BV, Avastin), a recombinant, humanized monoclonal antibody directed against VEGF, improves survival in combination with chemotherapy for first line treatment of metastatic colorectal cancer (CRC). The addition of BV to irinotecan/5-FU/leucovorin (IFL) resulted in a significant improvement in survival compared with IFL alone (p=0.00004; median survival increased from 15.6 to 20.3 months). Experience with BV in phase II studies, particularly in NSCLC, suggested that bleeding might be a safety signal. Therefore, patients receiving full-dose anticoagulation (FDAC) were excluded from the phase III CRC study. This analysis assesses the outcomes of patients with metastatic CRC who had a thrombotic event while receiving study treatment (BV or placebo), and remained on study while receiving FDAC. Methods. Patients with previously untreated metastatic CRC were randomized to IFL plus placebo (Arm 1) versus IFL plus BV (5 mg/kg; Arm 2). Thrombotic complications, including deep venous thr...