Combination Chemotherapy With or Without Bevacizumab in Treating Patients Who Have Undergone Surgery for High Risk Stage II or Stage III Colon Cancer

RATIONALE: Drugs used in chemotherapy work in different ways to stop the growth of tumor cells, either by killing the cells or by stopping them from dividing. Monoclonal antibodies, such as bevacizumab, can block tumor growth in different ways. Some block the ability of tumor cells to grow and spread. Others find tumor cells and help kill them or carry tumor-killing substances to them. Bevacizumab (Bv) may also stop the growth of tumor cells by blocking blood flow to the tumor. Giving combination chemotherapy together with bevacizumab after surgery may kill any tumor cells that remain after surgery. It is not yet known whether giving combination chemotherapy together with bevacizumab is more effective than combination chemotherapy alone in treating colon cancer in adjuvant setting.

PURPOSE: This randomized phase III trial is studying two different combination chemotherapy regimens with or without bevacizumab to compare how well they work in treating patients who have undergone surgery for high risk stage II or stage III colon cancer.

This was an open-label Phase III, multicenter, multinational, randomized, 3-arm study designed to evaluate the efficacy and safety of bevacizumab in combination with either intermittent fluorouracil/leucovorin with oxaliplatin (FOLFOX4) or capecitabine plus oxaliplatin (XELOX) versus FOLFOX4 regimen alone, as adjuvant chemotherapy in colon carcinoma.

The treatment phase consisted of two parts of 24 weeks for a total of 48 weeks. The first part (weeks 1 to 24) consisted of treatment with either FOLFOX4, FOLFOX4 in combination with bevacizumab, or XELOX in combination with bevacizumab. The second part (weeks 25 to 48) consisted of single-agent bevacizumab for patients randomized to either bevacizumab-containing arm, but was only an observation period for patients assigned to the FOLFOX4-alone arm.

Patients were to be followed for recurrence/new occurrence of colorectal cancer and survival. Patients who experienced a confirmed recurrence, occurrence of a new colorectal cancer during therapy, or experienced unacceptable toxicity were to be taken off study treatment but remain in study follow-up. Patients that came off therapy due to a confirmed recurrence/appearance of new colorectal cancer, were to be followed for survival until the end of the study follow-up period. The primary analysis was performed 36 months after the last patient has been randomized. After the primary analysis, patients continue to be followed for survival for at least a further 2 years ie, until all patients have been followed-up for at least 5 years following randomization.

Eligibility Criteria:
Inclusion Criteria

1. Signed written informed consent obtained prior to any study specific screening procedures.
2. Patient willing and able to comply with the protocol.
3. Age ≥ 18 years-of-age.
4. Histologically confirmed colon carcinoma, American Joint Cancer Committee/Union Internationale Contre le Cancer (AJCC/UICC) Stage II or Stage III defined as a tumor location ≥ 15 cm from the anal verge by endoscopy or above the peritoneal reflection at surgery. The patient was not to be a candidate for (neo) adjuvant radiotherapy. Note: Stage II patients were to be considered as high-risk patients fulfilling one of the following criteria:

   * T4 tumours,
   * Patients presenting with bowel obstruction or perforation,
   * Histological signs of vascular invasion (i.e. blood and lymphatic vessels) or perineural invasion,
   * Patients aged less than 50 years,
   * Patients with sub-optimal surgery (less than 12 nodes analyzed).
5. Curative surgery not less than 4 and not more than 8 weeks prior to randomization.
6. Eastern Cooperative Oncology Group (ECOG) performance status 0 or 1.
7. Life expectancy of ≥ 5 years.

Exclusion Criteria

1. Macroscopic or microscopic evidence of remaining tumour. Patients should never have had any evidence of metastatic disease (including presence of tumour cells in the ascites). The isolated finding of cytokeratin positive cells in bone marrow is not considered evidence of metastatic disease for purposes of this study.
2. Carcinoembryonic antigen \> 1.5 x upper limit of normal (ULN) after surgery (during screening period).
3. For patients with colostomy, unwilling to delay revision until at least 28 days after treatment completion.
4. Major surgical procedure, open biopsy, or significant traumatic injury within 28 days prior to study treatment start, not fully healed wounds, or anticipation of the need for major surgical procedure during the course of the study. Any central venous access device (CVAD) for chemotherapy administration must be inserted at least 2 days prior to treatment start.
5. Previous anti-angiogenic treatment for any malignancy; cytotoxic chemotherapy, radiotherapy or immunotherapy for colon cancer.
6. Other malignancies within the last 5 years (other than curatively treated basal cell carcinoma of the skin and/or in situ carcinoma of the cervix).
7. Females with a positive or no pregnancy test (within 7 days before treatment start) unless childbearing potential can be otherwise excluded (postmenopausal i.e. amenorrheic for at least 2 years, hysterectomy or oophorectomy).
8. Lactating women.
9. Fertile women (\< 2 years after last menstruation) and men of childbearing potential not willing to use effective means of contraception.
10. History or evidence upon physical examination of central nervous disease (CNS) disease (eg, primary brain tumour, seizure not controlled with standard medical therapy, any brain metastases).
11. History of psychiatric disability judged by the investigator to be clinically significant, precluding informed consent or interfering with compliance for oral drug intake.
12. Clinically significant (ie, active) cardiovascular disease. This includes, but is not limited to, the following examples: cerebrovascular accidents (≤ 6 months prior to randomization), myocardial infarction (≤ 1 year prior to randomization), uncontrolled hypertension (\>150/100 mmHg) while receiving chronic medication, unstable angina, New York Heart Association (NYHA) Grade II or greater congestive heart failure, serious cardiac arrhythmia requiring medication, clinically significant electrocardiogram (ECG) findings (e.g. QTc ≥ 440 msecs \[male\] 460 msecs \[female\] or ≥ 2º atrioventricular block, etc.).

    Patients who suffer from serious cardiac arrhythmia requiring medication can enter the study only if they are considered to be in a stable condition regarding both the arrhythmia and their medication. Patients with pacemakers are allowed to enter the study only if they are considered as being in a stable condition. In case of doubt, the investigator should obtain a consultation with a local cardiologist.
13. Lack of physical integrity of the upper gastro-intestinal tract, malabsorption syndrome, or inability to take oral medication.
14. Interstitial pneumonia or extensive symptomatic fibrosis of the lungs.
15. Known peripheral neuropathy ≥ Common terminology criteria for adverse events (CTCAE) version 3.0 Grade 1. Absence of deep tendon reflexes as the sole neurological abnormality does not render the patient ineligible.
16. Organ allografts requiring immunosuppressive therapy.
17. Serious, non-healing wound, ulcer, or bone fracture.
18. Evidence of bleeding diathesis or coagulopathy.
19. Current or recent (within 10 days prior to study treatment start) use of full-dose oral or parenteral anticoagulants or thrombolytic agent for therapeutic purposes.
20. Chronic, daily treatment with high-dose aspirin (\> 325 mg/day) or clopidogrel (\> 75 mg/day).
21. Chronic treatment with corticosteroids (dose of ≥ 10 mg/day methylprednisolone equivalent) (excluding inhaled steroids).
22. Serious intercurrent infections (uncontrolled or requiring treatment).
23. Known dihydropyrimidine dehydrogenase deficiency.
24. Current or recent (within the 28 days prior to randomization) treatment with another investigational drug or participation in another investigational study.
25. Patients with known allergy to Chinese hamster ovary cell proteins or other recombinant human or humanized antibodies or to any excipients of bevacizumab formulation, platinum compounds or to any other components of the study drugs.
26. History or presence of other disease, metabolic dysfunction, physical examination finding, or clinical laboratory finding giving reasonable suspicion of a disease or condition that contraindicates use of an investigational drug or patient at high risk from treatment complications.
27. Presence of proteinuria at baseline as defined by:

    - Patients with \> 1 g of protein/24 hour by a 24-hour urine collection.
28. Any laboratory values at baseline are as follows:

Haematology:

* Absolute neutrophil count (ANC) \< 1.5 x 109/L
* Platelet count \< 100 x 10\^9/L
* Haemoglobin \< 9 g/dL (may be transfused to maintain or exceed this level)
* International normalized ratio (INR) \> 1.5
* Activated partial prothrombin time (APTT) ≥ 1.5 x ULN

Biochemistry:

* Total bilirubin \> 1.5 x ULN
* aspartate aminotransferase (ASAT), alanine aminotransferase (ALAT) \> 2.5 x ULN
* Alkaline phosphatase (ALP) \> 2.5 x ULN
* Serum creatinine \> 1.5 x ULN or creatinine clearance ≤ 50 mL/min (e.g. Cockcroft-Gault formula).