Study of Gamma Interfereon in Metastatic Colorectal Carcinoma

Inclusion Criteria: * Metastatic colorectal cancer, histologically or cytologically confirmed * Age 18 or greater * Adequate hematologic function (ANC \> 1500, hemoglobin \> 10 g/dl, platelet count \> 100,000) * Adequate hepatic parameters (bilirubin \< 2.0, Alk. Phos \< 5 times normal, ALT \< 5 times normal) * Adequate renal function (creatinine \< 2.0) * Performance status ECOG 0-2 * 0-2 prior lines of chemotherapy for metastatic colorectal cancer are allowed. Prior 5-FU/LV or capecitabine allowed either in the adjuvant setting, or in the metastatic setting or both. * Absence of other serious concurrent medical illnesses * Evaluable or measurable disease for phase I; measurable disease only for phase II Exclusion Criteria: * Histologies other than adenocarcinoma * Previous grade 4 toxicity to 5-FU +/- LV or capecitabine * Uncontrolled brain metastases * Chronic diarrhea (greater than five bowel movements per day) * Previous chemotherapy or radiation therapy less than 4 weeks prior to study day 1 (less than 6 weeks for chemotherapy with Mitomycin or nitrosoureas) * Major surgery within 2 weeks before study entry * Known allergic sensitivity to leucovorin * Prior exposure to IFN-γ * Previous hematopoietic growth factor (e.g. epoetin alfa or darbepoietin less than 2 weeks prior to study day 1) * Pregnancy or breast feeding. Women of child-bearing potential must have a negative pregnancy test before the first dose. * Other co-existing malignancies or malignancies diagnosed within the last 5 years, with the exception of basal cell carcinoma or cervical cancer in situ * Inability to provide written and informed consent * Uncontrolled hypertension * History of deep venous thrombosis or CVA * Prior exposure to bevacizumab * Proteinuria \> 500 mg/24 hr