VEGF Trap in Treating Patients With Previously Treated Metastatic Colorectal Cancer

Inclusion Criteria: * histologically/cytologically confirmed metastatic colorectal metastatic cancer * measurable disease (at least 1 lesion accurately measured in at least 1 dimension (longest diameter) as\>20mm with conventional techniques or as \>10mm with spiral CT scan * \>=4 weeks from major surgery * at least 1prior line of systemic therapy for metastatic disease. Prior treatment with anti-epidermal growth factor receptor inhibitors is allowed. Last dose \>=4 weeks prior to randomization * Two cohorts: 1) bevacizumab naïveand; 2) bevacizumab treated * May have received prior thymidylate synthetase inhibitor concurrently with radiation as "radiation sensitizer". Last dose \>=4 weeks prior to randomization * Prior radiation treatment \>=4 weeks prior to randomization * Age\>=18 years * Life expectancy \>=3 months * ECOG\<=2 (Karnofsky=60%) * leukocytes \>3.0x10\^9/L * absolute neutrophil count \>1.5 x 10\^9/L * platelets\>75x10\^9/L * INR \<1.5 unless on warfarin * total bilirubin within 1.5xULN * AST/ALT≤2.5 X institution ULN * creatinine≤1.5xULN OR creatinine clearance \>60mL/min/1.73m2 for patients with creatinine levels above1.5x institution limits * Urinalysis negative for protein OR 24h urine for protein \<500 mg * full-dose anticoagulants with PT INR \>1.5 eligible provided that: a) patient is therapeutic on stable dose of warfarin or low molecular weight heparin; b) patients on warfarin, the upper target for INR is \<=3; c) no active bleeding/pathological condition carrying high bleeding risk * Eligibility of patients receiving medications known to affect activity/PK of VEGF Trap will be determined by PI * Women of childbearing potential and men must agree to use adequate contraception (hormonal or barrier method of birth control; abstinence) prior to study entry, for the duration of study participation, and for at least 6 months after completion of VEGF Trap therapy * Ability to understand/willingness to sign written informed consent Exclusion Criteria: * chemotherapy/radiotherapy within 4 weeks (6 weeks for nitrosoureas/mitomycin C) prior to study entry * Other investigational agents concurrently * History of prior anti-angiogenic therapy other than bevacizumab * Evidence of CNS disease * Known hypersensitivity to Chinese hamster ovary cell products/other recombinant human antibodies, and patients with a history of allergic reactions attributed to compounds of similar chemical/biologic composition to other agents used in the study. * Serious/non-healing wound/ulcer/bone fracture * History of abdominal fistula/GI perforation/bowel obstruction/intraabdominal abscess within 28 days of treatment * major surgical procedure, open biopsy or significant traumatic injury within 28 days prior to Day 1 therapy * anticipation of need for major surgical procedures during study * core biopsy within 7 days prior to Day 1 therapy * Patients with clinically significant cardiovascular disease * Evidence of bleeding diathesis or coagulopathy * PT INR \>1.5 unless the patient is on full-dose warfarin * Use of thrombolytic agents within 1 month of study initiation * Significant Proteinuria (\>500mg/24h): Urine protein should be screened by random urinalysis for protein. If dipstick positive (\>1+), 24-hour urine protein should be obtained and if \>500mg/24 h, patient will be excluded. * Uncontrolled intercurrent illness including but not limited to ongoing or active infection or psychiatric illness/social situations that would limit compliance with study * Pregnant women * HIV-positive patients on combination antiretroviral therapy are ineligible because of potential for PK interactions with VEGF Trap