Study of Efficacy and Safety of PDR001 in Patients With Advanced or Metastatic, Well-differentiated, Non-functional Neuroendocrine Tumors of Pancreatic, Gastrointestinal (GI), or Thoracic Origin or Poorly-differentiated Gastroenteropancreatic Neuroendocrine Carcinoma (GEP-NEC)

Inclusion Criteria:

- Pathologically confirmed, advanced (unresectable or metastatic):

- Well-differentiated (G1 or G2) based on local pathology report, non-functional
neuroendocrine tumor of GI, pancreatic or thoracic (including lung and thymus) origin.

- Poorly-differentiated GEP-NEC based on local pathology report

- No active symptoms related to carcinoid syndrome during the last 3 months prior to
start of study treatment.

- Patients must have been pretreated for advanced disease - the number of prior systemic
therapy/regimen depends on which origin for NET and for GEP-NEC

- Tumor biopsy material must be provided for all patients for the purpose of biomarker
analysis

- Radiological documentation of disease progression:

- Well-differentiated NET group: Disease progression while on/or after the last
treatment, and this progression must have been observed within 6 months prior to start
of study treatment (i.e. maximum of 24 weeks from documentation of progression until
study entry). Disease must show evidence of radiological disease progression based on
scans performed not more than 12 months apart.

- Poorly-differentiated GEP-NEC group: Disease progression while on or after prior
treatment.

Exclusion Criteria:

- Well-differentiated grade 3 neuroendocrine tumors; poorly-differentiated
neuroendocrine carcinoma of any origin (other than GEP-NEC); including NEC of unknown
origin, adenocarcinoid, and goblet cell carcinoid

- Pretreatment with interferon as last treatment prior to start of study treatment.

- Prior treatment for study indication with:

- Antibodies or immunotherapy within 6 weeks before the first dose of study treatment.

- PRRT administered within 6 months of the first dose.

- Systemic antineoplastic therapy

- Tyrosine kinase inhibitors within 14 days or 5 half-lives, whichever is longer, before
the first dose of study treatment.

- Prior PD-1- or PD-L1-directed therapy.

- Cryoablation, radiofrequency ablation, or trans-arterial embolization of hepatic
metastases

- History of severe hypersensitivity reactions to other monoclonal antibodies which in
the opinion of the investigator may pose an increased risk of a serious infusion
reaction.