Detailed results from Lexicon’s pivotal Phase 3 TELESTAR clinical study of telotristat ethyl in patients with carcinoid syndrome have been published. The article titled “Telotristat Ethyl, a Tryptophan Hydroxylase Inhibitor for the Treatment of Carcinoid Syndrome” is available online at the Journal of Clinical Oncology website at ascopubs.org/journal/jco.
TELESTAR was a global double-blind Phase 3 study which enrolled 135 patients from 12 countries with carcinoid syndrome whose symptoms were not adequately controlled on somatostatin analog therapy (SSA), the current standard of care. Data show that patients who added telotristat ethyl to SSA therapy at both the 250 mg and 500 mg doses experienced a statistically significant reduction from baseline compared to placebo in the average number of daily bowel movements over the 12-week study period (p<0.001), data-preserve-html-node="true" meeting the study’s primary endpoint. There was also a statistically significant reduction in the levels of urinary 5-hydroxyindole acetic acid (5-HIAA), the main metabolite of serotonin, from baseline to week 12 with a reduction of 40 mg/24 hours (250 mg arm) and 58 mg/24 hours (500 mg arm) versus an increase of 11 mg/24 hours in the placebo arm (p<0.001). data-preserve-html-node="true" Treatment with telotristat ethyl was generally well tolerated during the double-blind treatment period.
Eighty-five percent of the patients originally enrolled in TELESTAR opted to continue study participation, receiving treatment with 500 mg telotristat ethyl in a 36-week open-label extension (OLE) study. Results from the OLE showed sustained bowel movement responses to treatment and no additional safety signals. Additional results detailed in the publication showed evidence that telotristat ethyl may also improve stool consistency, reduce the urgency to defecate and reduce the use of rescue short-acting octreotide. The Lexicon clinical development team, headed by Chief Medical Officer Pablo Lapuerta, is “very encouraged about the potential benefits telotristat ethyl may bring in terms of bowel movement frequency and other measures of carcinoid syndrome severity.” Telotristat ethyl has received Fast Track and Orphan Drug designation from the U.S. Food and Drug Administration and has been granted priority review by the FDA with a Prescription Drug User Fee Act (PDUFA) target action date of February 28, 2017. If approved by the FDA, telotristat will be the first new treatment for carcinoid syndrome in more than ten years.