A Multicenter, Two Stage, Phase II Study, Evaluating the Efficacy of Oral BEZ235 Plus Best Supportive Care (BSC) Versus Placebo Plus BSC in the Treatment of Patients With Advanced Pancreatic Neuroendocrine Tumors (pNET) After Failure of mTOR Inhibitor Therapy.

Inclusion Criteria:

- Unresectable or metastatic, histologically confirmed low or intermediate grade
pancreatic neuroendocrine tumor with radiological evidence of disease progression
since last treatment

- Refractory disease to treatment with mTOR inhibitor

- Measurable disease per RECIST Version 1.1 using Computed Tomography (CT) or Magnetic
Resonance Imaging (MRI)

- Prior or concurrent therapy with SSA is permitted; a stable dose at least 2 months
prior to study start and must continue on the stable dose while receiving study
treatment; SSA is not considered as a systemic treatment.

- WHO PS ≤ 1

- Adequate bone marrow function or organ function

Exclusion Criteria:

- Previous treatment with any PI3K or AKT inhibitor

- Discontinuation prior mTOR inhibitor therapy due to toxicity

- Poorly differentiated neuroendocrine carcinoma, high-grade neuroendocrine carcinoma,
adenocarcinoid, goblet cell carcinoid and small cell carcinoma

- Radiotherapy, or major surgery within 4 weeks prior to study treatment start

- Hepatic artery embolization or cryoablation/ radiofrequency ablation of hepatic
metastasis within 2 months of study treatment start.

- More than 3 prior systemic treatment regimens (including cytotoxic chemotherapy,
targeted therapy, immunotherapy)

Other protocol defined inclusion/exclusion criteria may apply.