This is a randomized, double-blind, placebo-controlled multi-center phaseⅢstudy to evaluate efficacy and safety of oxaliplatin-based chemotherapy plus MB-6(320 mg/capsule, 6 capsules tid) in patients with stage 3 colorectal cancer who underwent surgical excision of their primary tumor.

The investigational new drug, MB-6, in the proposed clinical trial is to be used as an adjuvant therapy for metastatic colorectal cancer patients. All of six extracts have been used in human with a long history, and many literatures reported the medicinal use either individually or as ingredients of formulations. MB-6 may provide its therapeutic benefits via inhibition of tumor induction or enhancing the efficacy of chemotherapy in colorectal cancer.

Inclusion Criteria:

1. Men or women 20 years of age or older.
2. Histologically or cytologically confirmed stage 3 colorectal adenocarcinoma.
3. Complete resection of the primary tumor without gross or microscopic evidence of residual disease.
4. No more than 8 weeks have elapsed from the time of surgery and have recovered from the effects.
5. Eastern Cooperative Oncology Group Performance Status (ECOG PS) < 2 at the time of screening.
6. Hematological function: ANC≥1500/mm3, Hemoglobin ≥9.0 g/dL, Platelet count ≥100000/mm3.
7. Kidney function:Serum creatinine <2 mg/dL.
8. Liver function: AST ≤3 times ULN, ALT ≤3 times ULN, Total Bilirubin ≤2 times ULN.
9. Ability to understand and the willingness to sign a written informed consent document according to institutional guidelines.
10. Men and women of childbearing potential must agree to employ adequate contraception during the study period.

Exclusion Criteria:

1. History of second primary malignancies except for adequately treated basal cell carcinoma of the skin or carcinoma in situ of the cervix.
2. Systemic chemotherapy, immune therapy or experimental or approved antibodies/proteins (e.g. bevacizumab) administered after surgery and prior to randomization.
3. Concurrent treatment with any other anticancer therapy.
4. Radiotherapy ≤14 days prior to randomization.
5. Any unresolved toxicity > CTC (Common Toxicity Criteria) grade 1 from previous anti-cancer therapy (including radiotherapy) except haematological toxicity and alopecia.
6. Patients with congestive heart failure, epilepsy, or other significant medical conditions as judged by the investigator.
7. Contraindications to FOLFOX chemotherapy: peripheral neuropathy NCI CTC >1, liver failure, uncontrolled coronary heart disease, myocardial infarction within the previous 6 months before randomization.
8. Patient of child-bearing potential is evidently pregnant or is breast feeding.

A total of 184 patients with stage III colorectal cancer underwent surgery will be recruited into the study for receiving adjuvant therapy over 18 weeks.