Pretargeted Radioimmunotherapy in Metastatic Colorectal Cancer

Inclusion Criteria: 1. Metastatic colorectal cancer and failure to standard therapies (5-fluorouracil, irinotecan, oxaliplatin, anti-vascular endothelium growth factor, anti-epidermal growth factors in patients with RAS wild type tumors). A previous line with regorafenib is not required. 2. Elevated CEA serum level or proved CEA expression in tumor tissue 3. ≥ 18 years of age, 4. Given signed, written informed consent 5. Existence of at least one measurable tumor lesion by CT or MRI at the time of treatment, but no single lesion ≥ 8 cm in diameter. 6. At least 4 weeks recovery period after any major surgery, radiation, or chemotherapy, and total recovery from any acute toxicities associated with these prior treatments. 7. Life expectancy ≥ 3 months, Karnofsky performance status of ≥ 70% 8. Adequate hematology and renal function and hepatic function 9. Patients of childbearing potential must be willing to practice birth control during the study until at least 12 weeks after treatment, and women of childbearing potential must have a negative serum pregnancy test to enter the study Exclusion Criteria : 1. Known central nervous system metastatic disease 2. \> 25% bone marrow involvement 3. CEA plasma levels \>2,000 ng/mL 4. Patients with successfully treated non-melanoma skin cancer or carcinoma in situ of the cervix are eligible, while patients with other prior malignancies must have had at least a 3-year disease-free interval. 5. HIV positive, hepatitis B-antigen positive, or hepatitis C positive patients 6. Known autoimmune disease, 7. Known history of unstable angina, myocardial infarction, or congestive heart failure present within 6 months or clinically significant cardiac arrhythmia (other than stable atrial fibrillation) requiring anti-arrhythmia therapy, no known history of clinical significant, active chronic obstructive pulmonary disease, or other moderate to severe chronic respiratory illness present within 6 months 8. Infection requiring intravenous antibiotic use within 1 week before inclusion, 9. Corticosteroids are not allowed within 2 weeks of study entry nor during the study except low doses (i.e., 20 mg/day of prednisone or equivalent) to treat nausea or other illness such as rheumatoid arthritis. 10. Patients who received a treatment containing a nitrosourea compound will not be enrolled for at least 6 weeks after the end of that treatment. 11. Known hypersensitivity to murine antibodies or proteins 12. Immunization against TF2 for patients who has already received injection of TF2 13. Adult patient unable to give informed consent because of intellectual impairment. 14. Adult patient protected by the French law \-