To validate the mechanism of action of LX1031, treated patients were categorized based on whether or not they reached a threshold of 15% reduction in urinary 5-HIAA, a biomarker of serotonin synthesis. The resulting analysis showed that the 5-HIAA biomarker could distinguish patients who responded to the investigational drug LX1031 across multiple clinically-relevant measures. After four weeks of receiving 1,000 mg of LX1031 four times daily, 73% of patients who reached the biomarker reduction threshold reported experiencing adequate relief of their IBS pain and discomfort as compared to only 11% of patients not meeting the biomarker response threshold (p<0.01). These results illustrate the potential utility of an objective biochemical marker in the management of patients with IBS. In addition, the data suggest the ability to identify patients who are most likely to benefit from therapy with LX1031.

"These findings are especially important in IBS, which has been lacking an objective biochemical marker. The 5-HIAA biomarker correlation with clinical response in this study validates the mechanism of action of LX1031," said Dr. Philip Brown, senior vice president of clinical development at Lexicon. "We intend to integrate measures of 5-HIAA in future clinical development of LX1031, which could reduce variability and improve response rates."

SOURCE Lexicon Pharmaceuticals, Inc.