 Patients receive ziv-aflibercept intravenously IV over 15-30 minutes followed by FOLFIFRI chemotherapy comprising leucovorin calcium IV over 2 hours, irinotecan hydrochloride IV over 90 minutes, and fluorouracil IV over 46 hours on day 1. Courses repeat every 2 weeks in the absence of disease progression or unacceptable toxicity. 