Sirolimus for Injection (Albumin Bound) Combined With Octreotide Long-acting Injection in Patients With Metastatic Gastroenteropancreatic Neuroendocrine Tumors

Inclusion Criteria: * 1\. Unresectable locally advanced or metastatic G1/G2 GEP-NETs diagnosed by histology, according to the 2019 WHO histological grading criteria. * 2\. Having poor prognostic factors. * 3\. Non-functional GEP-NETs are required. * 4\. At least one evaluable lesion meets the RECIST V1.1 standard (Applicable only to the phase II safety run-in stage) * 6\. ECOG 0\~2. * 7\. Organ function reserve is good. * 8\. Be able to sign a written informed consent form. Exclusion Criteria: * 1\. Patients who have previously received SSTR-targeted therapies (including somatostatin analogs \[SSAs\] and peptide receptor radionuclide therapy) and/or mTOR inhibitors (Patients who received SSAs in the adjuvant setting and experienced recurrence ≥6 months after treatment completion may be enrolled)\[ Applicable to Phase II dose expansion and Phase III stages\]. * 2\. Has uncontrolled/severe diarrhea or an axillary temperature \> 38.0°C at enrollment. * 3\. Received treatment with other unlisted clinical investigational drugs within 4 weeks prior to the first use of the investigational drug. * 4\. Undergone major surgical procedures within 4 weeks prior to the first use of the investigational drug and have not fully recovered. * 5\. Received systemic use of corticosteroids or other immunosuppressive therapy within 2 weeks prior to the first use of the study drug. * 6\. With an infection that requires systemic anti-infective treatment within 2 weeks prior to the first use of th…