Antiproliferative Effects of Telotristat Ethyl in Patients with Neuroendocrine Tumors: The TELEACE Real-World Chart Review Study

Cancer Management and Research, 2020


Neuroendocrine tumors (NETs) associated with carcinoid syndrome (CS) overproduce serotonin, mediated by tryptophan hydroxylase-1 (TPH1). The TPH inhibitor telotristat ethyl (TE) reduces peripheral serotonin and relieves CS symptoms. We conducted a real-world clinical practice study to explore the effects of TE on tumor growth in patients with NETs and CS.

Patients and methods

Single-arm, pre/post chart review study of patients with advanced NETs who received TE for ≥6 months and had ≥2 radiological scans within 12 months before and ≥1 scan after TE initiation. Linear regression and longitudinal analyses assessed changes in tumor size controlling for background NET treatment.


Two hundred patients were enrolled, most (61%) had well-differentiated gastrointestinal NETs (61%) and received TE for an average of 12 months (SD, 7.3). Mean reduction in tumor size after TE initiation was 0.59 cm (p=0.006). Longitudinal analysis showed an 8.5% reduction in tumor size (p=0.045) from pre- to post-TE periods. Documented NET treatment prior to initiating TE and time between scans were not significant predictors of changes in tumor size. Results were consistent in a subgroup of patients with the same documented NET treatment before and after initiating TE.


TE may have antitumor effects consistent with serotonin overproduction in tumor growth.

View abstract


Morse MA, Liu E, Joish VN, Huynh L, Cheng M, Duh MS, Seth K, Lapuerta P, Metz DC