Purpose: In the placebo-controlled Phase III TELE-STAR (Telotristat Etiprate for Somatostatin Analogue Not Adequately Controlled Carcinoid Syndrome) trial, the oral tryptophan hydroxylase inhibitor telotristat ethyl significantly reduced bowel movement (BM) frequency during a 12-week, double-blind treatment period in 135 patients with metastatic neuroendocrine tumors with carcinoid syndrome and >= 4 BMs per day. Patients (mean [SD] age, 63.5 [8.9] years; mean [SD] body mass index, 24.9 [4.9] kg/m(2)) received placebo, telotristat ethyl 250 mg, or telotristat ethyl 500 mg 3 times per day (TID) in addition to somatostatin analogue therapy. Weight loss is associated with uncontrolled carcinoid syndrome and may be associated with reduced survival. Methods: Assessment of the occurrence of weight change >= 3% at week 12 was prespecified in the statistical analysis plan. Findings: In 120 patients with weight data available, weight gain >= 3% was observed in 2 of 39 patients (5.1%) taking placebo [1.1), 7 of 41 (17.1%) taking telotristat ethyl 250 mg TID, and 13 of 40 (32.5%) taking telotristat ethyl 500 mg TID (P = 0.0017) at week 12. Weight loss >= 3% was observed in 5 of 39 patients (12.8%) taking placebo TID, 4 of 41 (9.8%) taking telotristat ethyl 250 mg TID, and 6 of 40 (15.0%) taking telotristat ethyl 500 mg TID (P = 0.77). Biochemical and metabolic parameters of serum albumin and cholesterol significantly increased (P = 0.02 and P = 0.001, respectively) in patients gaining weight and decreased in patients who lost weight, suggesting an improvement in overall nutritional status. (C) 2018 The Authors. Published by Elsevier HS Journals, Inc.