telotristat and Diarrhea

Telotristat etiprate, a tryptophan hydroxylase inhibitor, was previously evaluated in a Phase II randomized, placebo-controlled clinical trial in patients with carcinoid syndrome (CS) and diarrhea not adequately controlled by octreotide. The objective of the current study was to characterize the symptom experiences of patients participating in that trial.. Consenting patients participated in one-on-one, qualitative interviews focused on eliciting symptoms they had experienced in association with their CS diagnosis and recollection of symptom changes they experienced while participating in the Phase II trial.. Among the 23 patients who participated in the previous 4-week dose-escalation study, 16 were eligible for interviews and 11 participated in the present study. The median time from study completion to the interview was 31 months; 4 of 11 patients were receiving telotristat etiprate in a follow-up, open-label trial at the time of interview. All of the patients (100%) described diarrhea as a symptom of CS, with effects on the emotional, social, and physical aspects of their lives. Improvement in diarrhea during the study was described by 82% of participants, and was very impactful in several patients. Results led to the design and implementation of a larger interview program in Phase III and helped to establish a definition of clinically meaningful change for the clinical development program.. The diarrhea associated with CS can have a large impact on daily lives, and patient interviews can characterize and capture clinically meaningful improvements with treatment. ClinicalTrials.gov Identifier: NCT00853047.

Topics: Aged; Antineoplastic Agents; Diarrhea; Female; Humans; Interviews as Topic; Male; Malignant Carcinoid Syndrome; Middle Aged; Phenylalanine; Pyrimidines; Treatment Outcome

Serotonin produced by neuroendocrine tumors is believed to be a principal cause of the diarrhea in carcinoid syndrome. We assessed the safety and efficacy of telotristat etiprate, an oral serotonin synthesis inhibitor, in patients with diarrhea associated with carcinoid syndrome. In this prospective, randomized study, patients with evidence of carcinoid tumor and ≥4 bowel movements (BMs)/day despite stable-dose octreotide LAR depot therapy were enrolled in sequential, escalating, cohorts of four patients per cohort. In each cohort, one patient was randomly assigned to placebo and three patients to telotristat etiprate, at 150, 250, 350, or 500 mg three times a day (tid). In a subsequent cohort, one patient was assigned to placebo and six patients to telotristat etiprate 500 mg tid. Patients were assessed for safety, BM frequency (daily diary), 24 h urinary 5-hydroxyindoleacetic acid (u5-HIAA), and adequate relief of carcinoid gastrointestinal symptoms (using a weekly questionnaire). Twenty-three patients were treated: 18 received telotristat etiprate and five received placebo. Adverse events were generally mild. Among evaluable telotristat etiprate-treated patients, 5/18 (28%) experienced a ≥30% reduction in BM frequency for ≥2 weeks, 9/16 (56%) experienced biochemical response (≥50% reduction or normalization in 24-h u5-HIAA) at week 2 or 4, and 10/18 (56%) reported adequate relief during at least 1 of the first 4 weeks of treatment. Similar activity was not observed in placebo-treated patients. Telotristat etiprate was well tolerated. Our observations suggest that telotristat etiprate has activity in controlling diarrhea associated with carcinoid syndrome. Further studies confirming these findings are warranted.

Topics: Adult; Aged; Aged, 80 and over; Antineoplastic Agents, Hormonal; Diarrhea; Female; Gastrointestinal Agents; Humans; Hydroxyindoleacetic Acid; Male; Malignant Carcinoid Syndrome; Middle Aged; Octreotide; Phenylalanine; Pyrimidines; Serotonin Antagonists; Treatment Outcome

Telotristat ethyl (Xermelo™) is a peripheral tryptophan hydroxylase (TPH) inhibitor that was developed by Lexicon Pharmaceuticals, Inc. for the treatment of carcinoid syndrome. Many neuroendocrine tumours secrete serotonin (5-HT) into the blood stream, resulting in a number of symptoms, notably diarrhoea. Telotristat ethyl inhibits TPH, thereby reducing the production of 5-HT. In February 2017, telotristat ethyl was approved in the USA for the treatment of carcinoid syndrome diarrhoea in combination with somatostatin analog (SSA) therapy in adults inadequately controlled by SSA therapy. This article summarizes the milestones in the development of telotristat ethyl leading to this first global approval.

Topics: Animals; Diarrhea; Drug Approval; Drug Therapy, Combination; Humans; Malignant Carcinoid Syndrome; Neuroendocrine Tumors; Phenylalanine; Pyrimidines; Randomized Controlled Trials as Topic; Somatostatin; Tryptophan Hydroxylase; United States; United States Food and Drug Administration