Lexicon Reports Initial Clinical Trial Results for LX1031, an Investigational New Drug for Irritable Bowe...( PHILADELPHIA and THE WOODLANDS Te...),Health

PHILADELPHIA and THE WOODLANDS, Texas, Oct. 15 /PRNewswire-FirstCall/ -- Lexicon Pharmaceuticals, Inc. (Nasdaq: LXRX) presented data regarding Phase 1 clinical trial results for LX1031 at the annual meeting of the American College of Gastroenterology in Philadelphia, Pennsylvania. The studies demonstrated that LX1031 was generally well-tolerated at all dose levels and that exposure levels in blood were low. A statistically significant reduction of urinary 5-hydroxyindoleacetic acid (5-HIAA), a metabolite of serotonin and biomarker for serotonin production, was observed in subjects who received the highest dose tested, 2,000 mg per day, for two weeks. Over the fourteen-day trial, no dose-limiting toxicities were observed.

LX1031 was developed as an orally-administered potential treatment for irritable bowel syndrome (IBS) and other gastrointestinal (GI) disorders. Preclinical studies demonstrated that LX1031 lowers serotonin levels in the intestine without affecting levels in the brain.

"We are pleased with the results of our initial human studies of LX1031," said Philip M. Brown, M.D., J.D., Lexicon's vice president of clinical development. "The compound was well tolerated, consistent with our preclinical observations, and we are encouraged by the 5-HIAA biomarker results. We look forward to progressing LX1031 into Phase 2 clinical trials in 2008."

About LX1031 and Irritable Bowel Syndrome

Based on findings from Lexicon's proprietary knock-out mouse technology, LX1031 was developed by Lexicon's small molecule drug discovery team as an orally-administered inhibitor of tryptophan hydroxylase, a key enzyme in the synthesis of serotonin.

Serotonin is a neurotransmitter found primarily in the
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