The purpose of this study is to assess FOLFIRI+aflibercept efficacy in patients with or without ACE polymorphisms in terms of Progression-free survival (PFS).

Inclusion Criteria:

1. Signed and dated informed consent, and willing and able to comply with protocol requirements,
2. Histologically proven adenocarcinoma of the colon and/or rectum,
3. Metastatic disease confirmed.
4. Existence of at least one measurable unidimensional lesion using CT or MRI based on the RECIST criteria, version 1.1
5. Patients with metastatic colorectal cancer (mCRC) that is resistant to or has progressed after an oxaliplatin-containing regimen.
6. Age ≥18 years
7. World Health Organization (WHO) Performance status (PS) 0-2,
8. Hematological status: neutrophils (ANC) ≥1.5x109 /L; platelets ≥100x109 /L; haemoglobin ≥9g/dL
9. Adequate renal function: serum creatinine level < 1.5 x ULN
10. Adequate liver function: serum bilirubin ≤1.5 x upper normal limit (ULN), alkaline phosphatase (ALP) <5xULN
11. Proteinuria <2+ (dipstick urinalysis) or ≤1g/24hour.
12. Regular follow-up feasible.
13. For female patients of childbearing potential, negative serum pregnancy test
14. Female patients must commit to using reliable and appropriate methods of contraception until at least three months after the end of study treatment (when applicable). Male patients with a partner of childbearing potential must agree to use contraception in addition to having their partner use another contraceptive method during the trial.

Exclusion Criteria:

1. Uncontrolled hypercalcemia,
2. Pre-existing permanent neuropathy (NCI grade >2)
3. Uncontrolled hypertension (defined as systolic blood pressure >150 mmHg and/or diastolic blood pressure >100 mmHg), or history of hypertensive crisis, or hypertensive ncephalopathy,
4. Concomitant protocol unplanned antitumor therapy (e.g. chemotherapy, molecular targeted therapy, immunotherapy),
5. Treatment with any other investigational medicinal product within 28 days prior to study entry.
6. Other serious and uncontrolled non-malignant disease,
7. History or evidence upon physical examination of CNS metastasis unless adequately treated (e.g. non irradiated CNS metastasis, seizure not controlled with standard medical therapy),
8. Known Gilbert's syndrome
9. Intolerance to atropine sulfate or loperamide
10. Known dihydropyrimidine dehydrogenase deficiency
11. Treatment with CYP3A4 inducers unless discontinued > 7 days prior to inclusion
12. Any of the following in 3 months prior to inclusion: grade 3-4 gastrointestinal bleeding (unless due to resected tumor), treatment resistant peptic ulcer disease, erosive esophagitis or gastritis, infectious or inflammatory bowel disease, or diverticulitis.
13. Other concomitant or previous malignancy, except: i/ adequately treated insitu carcinoma of the uterine cervix, ii/ basal or squamous cell carcinoma of the skin, iii/ cancer in complete remission for >5 years,
14. Any other serious and uncontrolled non-malignant disease, major surgery or traumatic injury within the last 28 days
15. Pregnant or breastfeeding women,
16. Patients with known allergy to any excipient to study drugs,
17. History of myocardial infarction and/or stroke within 6 months prior to inclusion, NYHA class III and IV congestive heart failure
18. Bowel obstruction.