Telotristat Ethyl for the Treatment of Carcinoid Heart Disease in Patients With Metastatic Neuroendocrine Tumor

Inclusion Criteria: * Patients who are \>= 18 years old will be eligible for the study * Histopathologically-confirmed,metastatic neuroendocrine tumor and/or locally/regionally advanced neuroendocrine tumor * Documented history of carcinoid syndrome based on clinical parameters * Currently receiving stable-dose somatostatin analog (SSA) therapy defined as \>= 2 months * Dose of long-acting release (LAR) or depot SSA therapy and on at least: * Octreotide LAR at 30 mg every 4 weeks * Lanreotide depot at 120 mg every 4 weeks * Patients who cannot tolerate SSA therapy at a level indicated above will be allowed to enter at their highest tolerated dose * Ability and willingness to provide written informed consent * Patients of childbearing potential must agree to use an adequate method of contraception during the study and for 30 days after the last dose of telotristat ethyl * Childbearing potential is defined as those who have not undergone surgical sterilization (eg. documented hysterectomy, tubal ligation, or bilateral salpingo-oophorectomy) or those who are not considered postmenopausal (defined as 12 months of spontaneous amenorrhea). * Adequate methods of contraception, defined as having a failure rate of \< 1% per year, for patients or their partner include the following: condom with spermicidal gel, diaphragm with spermicidal gel, intrauterine device, surgical sterilization, vasectomy, oral contraceptive pill, depo-progesterone injections, progesterone…