Open Label Study to Analyze the Effect of Telotristat Ethyl on Weight Regulation/Gain

This single arm study will evaluate whether Xermelo (telotristat ethyl) associated weight gain is affects lean body mass, dietary intake, and physical and cognitive functioning among neuroendocrine tumor (NET) patients with a history of carcinoid syndrome.

The purpose of this study is to examine the mechanisms of weight gain associated with the drug telotristat ethyl (Xermelo) among patients with a neuroendocrine tumor (NET) with history of carcinoid syndrome. We want to know if taking Xermelo affects patients' lean body mass, quality of life, dietary intake, and physical and cognitive functioning during treatment. A better understanding of the mechanisms of weight gain from Xermelo may allow us to determine whether this drug may be beneficial for treating carcinoid syndrome, cachexia, or weight loss seen in other diseases.