Gastroenteropancreatic Neuroendocrine Tumor (GEP-NET) originates from the hormone producing cells of the gut along with rectum and pancreas. GEP-NET represents 75% of all neuroendocrine tumors (NETs). The incidence is 2.5 to 6.2 cases per 100,000 population and 5-year mean survival rate of 60% in the United States. No significant risk factor have been identified. But 25% of GEP-NETs have been associated with hereditary conditions like Multiple Endocrine Neoplasia type 1 (MEN-1), type-2 (MEN-2), Von Hippel Lindau disease (VHL gene), tuberous sclerosis complex (TSC) and neurofibromatosis type-1 (NF-1). Alterations and loss of various chromosomes result in the progression of GEP-NETs. Researchers are still challenged in exploring innate and adaptive immune systems. Immunotherapy has shown a promising development in the past few years. One optimistic treatment modality is immunotherapy, with much progress seen in the last decade. We review all the different classes of drugs, FDA approved or still under clinical trials directed at the therapy of the GEP-NET
