A Study of Anlotinib in Patients With Gastroenteropancreatic Neuroendocrine Tumor G3

Inclusion Criteria: * Patients should participate in the study voluntarily and sign informed consent; * 18-75 years old; * Histopathological proven diagnosis of high grade (G3) advanced Gastroenteropancreatic Neuroendocrine Tumor(Unresectable locally advanced or distant Metastatic). the classification is based on the Ki-67 proliferative index \>20%(WHO 2010),and Provision of qualified pathological tissue for central review; * Progression during or after treatment with first-line systematic chemotherapy; * At least one measurable nidus (by RECIST1.1); * Main organs function is normal; * Eastern Cooperative Oncology Group(ECOG) performance status(PS):0-1,Life expectancy of more than 12 weeks; * Women of childbearing potential should agree to use and utilize an adequate method of contraception (such as intrauterine device，contraceptive and condom) throughout treatment and for at least 6 months after study is stopped；the result of serum or urine pregnancy test should be negative within 7 days prior to study enrollment，and the patients required to be non-lactating；Man participants should agree to use and utilize an adequate method of contraception throughout treatment and for at least 6 months after study is stopped; Exclusion Criteria: * Diagnosed with low or intermediate (G1,G2) neuroendocrine tumors, Manec, adenocarcinoma; * Functional neuroendocrine tumors(NETs) which need to be treated with long acting somatostatin analogue(SSAs) to control disease related syndromes, such as insulinoma, gastrinoma, glucagonoma, somatostatinoma, accompanied by carcinoid syndrome, Zollinger-Ellison syndrome or other active symptoms; * Other malignancies diagnosed within the previous 5 years, except basal cell carcinoma or cervical carcinoma in situ after radical resection； * Have received anti-vascular endothelial growth factor（VEGF）/VEGFR targeted drugs and progressed upon these drugs； * Patients with factors that could affect oral medication (such as dysphagia，chronic diarrhea, intestinal obstruction etc.) * Patients with any severe and/or unable to control diseases，including： 1. Blood pressure unable to be controlled ideally(systolic pressure≥150 mmHg，diastolic pressure≥100 mmHg); 2. Patients with Grade 1 or higher myocardial ischemia, myocardial infarction or malignant arrhythmias(including QT≥480ms) and patients with Grade 1 or higher congestive heart failure (NYHA Classification); 3. Patients with active or unable to control serious infections; 4. Patients with cirrhosis, decompensated liver disease, or active hepatitis; 5. Patients with poorly controlled diabetes (fasting blood glucose(FBG)\>10mmol/L) 6. Urine protein ≥ ++，and 24-hour urinary protein excretion\>1.0g confirmed; * Patients had surgery (except biopsy) within 28 days or the surgical incision has not fully healed before the first study drug implementation; * Patients with brain metastasis or spinal cord compression which had not surgical and / or radiation therapy,or which had previous treatment but there is no clinical imaging evidence proving the condition is stable; * Anti-tumor therapy was performed within 4 weeks prior to initiation of the study treatment, including but not limited to chemotherapy, radical radiotherapy, bio-targeted therapy, immunotherapy, anti-tumor treatment of traditional Chinese medicine, hepatic artery embolization, hepatic metastatic cryoablation or radiofrequency ablation surgery.Palliative radiotherapy for a bone metastasis lesion within 2 weeks prior to the initiation of the investigational treatment; * The toxic reaction of previous anticancer treatment has not been restored to grade 0 or 1 (except hair loss); * Patients with arterial or venous thromboembolic events occurred within 6 months, such as cerebrovascular accident (including transient ischemic attack), deep vein thrombosis and pulmonary embolism; * Imaging showed tumors have involved important blood vessels or by investigators determine likely during the follow-up study and cause fatal hemorrhage; * Patients with drug abuse history and unable to get rid of or Patients with mental disorders; * Patients participated in other anticancer drug clinical trials within 4 weeks; * History of immunodeficiency; * Pregnancy(Positive detection of pregnancy before drug use)or lactation; * Patients with concomitant diseases which could seriously endanger their own safety or could affect completion of the study according to investigators' judgment;