Lexicon reports Phase II IBS-D data for LX1033

Lexicon Pharmaceuticals Inc. (NASDAQ:LXRX) reported data on Tuesday from a 373-patient Phase II trial evaluating LX1033 to treat diarrhea-predominant irritable bowel syndrome (IBS-D). In the trial, all three doses of oral LX1033 -- twice-daily 500 mg, twice-daily 1,000 mg and thrice-daily 500 mg -- missed the primary endpoint of improving stool consistency from baseline to day 28 vs. placebo. Lexicon said early terminations in the trial may have "enhanced the placebo response rate." All three doses of LX1033 did meet the secondary endpoint of reducing plasma 5-hydroxyindoleacetic acid (5-HIAA) levels -- a biomarker for serotonin synthesis -- from baseline to day 28 vs. placebo. Lexicon said additional details may be provided during its R&D day on Thursday. LX0133 is a locally-acting serotonin synthesis inhibitor. ...