Abstract

Telotristat ethyl, a tryptophan hydroxylase inhibitor, was efficacious and well tolerated in the phase 3 TELESTAR study in patients with carcinoid syndrome (CS) experiencing ≥ 4 bowel movements per day (BMs/day) while on somatostatin analogs (SSAs). TELECAST, a phase 3 companion study, assessed the safety and efficacy of telotristat ethyl in patients with CS (diarrhea, flushing, abdominal pain, nausea or elevated urinary 5-hydroxyindoleacetic acid (u5-HIAA)) with < 4 BMs/day on SSAs (or ≥ 1 symptom or ≥ 4 BMs/day if not on SSAs) during a 12-week double-blind treatment period followed by a 36-week open-label extension (OLE). The primary safety and efficacy endpoints were incidence of treatment-emergent adverse events (TEAEs) and percent change from baseline in 24-h u5-HIAA at week 12. Patients (N = 76) were randomly assigned (1:1:1) to receive placebo or telotristat ethyl 250 mg or 500 mg 3 times per day (tid); 67 continued receiving telotristat ethyl 500 mg tid during the OLE. Through week 12, TEAEs were generally mild to moderate in severity; 5 (placebo), 1 (telotristat ethyl 250 mg) and 3 (telotristat ethyl 500 mg) patients experienced serious events, and the rate of TEAEs in the OLE was comparable. At week 12, significant reductions in u5-HIAA from baseline were observed, with Hodges–Lehmann estimators of median treatment differences from placebo of −54.0% (95% confidence limits, −85.0%, −25.1%, P < 0.001) and −89.7% (95% confidence limits, −113.1%, −63.9%, P < 0.001) for telotristat ethyl 250 mg and 500 mg. These results support the safety and efficacy of telotristat ethyl when added to SSAs in patients with CS diarrhea (ClinicalTrials.gov identifier: Nbib2063659).

Document Type

Article

Publication Date

3-1-2018

Notes/Citation Information

Published in Endocrine-Related Cancer, v. 25, issue 3, p. 309-322.

© 2018 The authors

This work is licensed under a Creative Commons Attribution 4.0 International License.

Digital Object Identifier (DOI)

https://doi.org/10.1530/ERC-17-0455

Funding Information

This work was supported by Lexicon Pharmaceuticals, Inc., The Woodlands, TX, USA.

Related Content

Supplementary date is linked to the online version of the paper at https://doi.org/10.1530/ERC-17-0455.

EndoRelatedCancer_25-3_309-322_suppdata.pdf (86 kB)
Supplementary Data

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