Study of Apatinib and Capecitabine Combination to Maintain Treating Metastatic Colorectal Cancer

To control apatinib and capecitabine combination to maintain treating metastatic colorectal cancer.

To control apatinib and capecitabine combination to maintain treating metastatic colorectal cancer,primary endpoint include in mPFS; secondary endpoint include in mOS, tolerance and security.

Eligibility Criteria:
Inclusion Criteria:

1. Informed consent form should be issued prior to conducting any research process;
2. Men or women aged 18-75 years;
3. Patients with advanced and / or metastatic colorectal cancer confirmed by histology or cytology;
4. Patients who has not exposed to apatinib previously and had received oxaliplatin combined with fluorouracil chemotherapy;
5. The estimated survival time is longer than 3 months;
6. ECOG score was 0 or 1;
7. According to the RECIST v1.1 guidance, at least 1 lesion(who had not received radiotherapy) showed that the longest diameter≥10mm(except for lymph node, the short axis of the lymph node must be≥15mm) through CT or MRI(intravenous contrast agent was preferred ) accurate measurement and the lesion should be suitable for repeatable and accurate measurement; the lesion located in the previously irradiated area can be used as a measurable lesion if the lesion was proved in progress;
8. With sufficient organ and bone marrow function, defined as follows:

   * Hb≥9 g/dL
   * Absolute neutrophil count ≥1.0 × 109 /L
   * Platelet count≥75 × 109 /L
   * Serum bilirubin ≤ 1.5 × ULN, which would not be appropriate for patients with Gilbert syndrome (Persistent or recurrent hyperbilirubinemia, mainly unconjugated bilirubin, with no evidence of hemolysis or abnormal liver pathology) which can consult a doctor
   * ALT\&AST ≤ 2.5 × ULN; for patients with liver metastases, ALT\&AST ≤ 5 × ULN Calculate the creatinine clearance rate by Cockcroft-Gault formula
   * Creatinine clearance rate measured( by actual body weight) or by measuring urine collection for 24 hours\> 40 mL/min(the value of the measurement of the 24 - hour urine collection will be used to determine eligibility if the two methods are used)
9. Women of childbearing age must have a pregnancy test (serum or urine) within 7 days before inclusion, the results should be negative and they are willing to use the appropriate methods of contraception during the trial and within 6 months of the last experimental drug administration. Men should agree to use appropriate methods of contraception during the trial and within 6 months of the last experimental drug administration;
10. Patients volunteered to participate in the trial and signed informed consent form with good compliance.

Exclusion Criteria:

1. Patients with hypertension and can not be reduced to the normal range with antihypertensive drugs(systolic pressure \>140 mmHg / diastolic pressure \> 90 mmHg),patients with coronary heart disease more than grade II, arrhythmia (including QTc interval Prolongation men\>450 ms, women \>470 ms) and cardiac insufficiency;
2. With a variety of factors affecting oral drugs(such as unable to swallow, nausea and vomiting, chronic diarrhea and intestinal obstruction, etc.);
3. Special note: patients with the risk of gastrointestinal bleeding can not be included, including the following: active peptic ulcer lesions and fecal occult blood (+ +); patients with melena and hematemesis in 3 months; for patients with fecal occult blood (+) and primary gastric tumor without surgery should be carried out gastroscopy, patients with ulcero carcinoma of stomach and believed to cause the lesion to bleed by the physician;
4. Abnormal coagulation function(INR\>1.5×ULN、 APTT\>1.5×ULN) with bleeding tendency;
5. With Symptomatic central nervous system metastasis;
6. Pregnant or lactating women;
7. Other patients unsuitable for inclusion considered by the physician.