AMT-PET in Monitoring Telotristat Etiprate Treatment in Participants With MetastaticNeuroendocrine Neoplasm

Inclusion Criteria: * Histopathologically confirmed, well-differentiated metastatic NETs * Receiving stable-dose somatostatin analog (long-acting release \[LAR\], depot) for \> 3 months before enrollment. * Patients with 5-HIAA levels above or below the upper limit of normal range and those with unknown values at baseline are allowed to participate. * Able to lie within the PET scanner for at least 70 minutes while undergoing scanning. * ECOG performance status of 2 or better. * Physical exam, CBC and Multiphasic (including electrolytes, BUN, creatinine, total bilirubin, AST, and ALT) must be done within 28 days of PET imaging and demonstrate adequate renal and liver function. Creatinine ≤ 2.5, total bilirubin ≤ 1.5 x upper limit of normal (ULN). AST and ALT ≤ 2.5 ULN. * Patient must have a least one lesion greater than 2 cm on standard imaging (CT, MR, octreotide, or dotatate imaging within 8 weeks of the start of the study) that is judged amenable to AMT-PET. * Women of child bearing potential must not be pregnant or breastfeeding. A negative urine or blood pregnancy test must be obtained in women with child bearing potential. Men and women with reproductive potential must agree to use adequate contraception (hormonal or barrier method of birth control; abstinence) on study entry and for the duration of study participation. * Eligible and consent signed for imaging with AMT PET under protocol 2011-053. Exclusion Criteria: * Patients experiencing more than 12 watery bowel…