Sintilimab Combined With IBI310 and Surufatinib for the Treatment of G3-NET and NEC (NESSIE)

Fully aware of this study and voluntary to sign the informed consent form (the informed consent form must be signed before any trial-specific procedure is performed);

Aged 18-75 (inclusive);

Histologically or cytologically confirmed patients with inoperable or metastatic high-grade neuroendocrine neoplasm (Ki67 index > 20% or with mitotic count of more than 20 mitoses per high power field);

Patients who failed to receive standard treatment (Have progressed on previous treatment, or treatment toxicity and side effects are not tolerated), or cannot receive standard treatment (including patients who are intolerant to standard treatment, who are judged by the investigator to be unsuitable for standard treatment or who refuse to receive standard treatment), or who have no standard treatment plan;