Symphony Icon and Lexicon Pharmaceuticals are collaborating on the clinical development of Lexicon’s LX1031, LX1032 and LX6171 programs.  For more information about the clinical development of these programs, please visit Lexicon’s corporate website at www.lexpharma.com.

LX1031

LX1031 is an orally-delivered small molecule compound that is being developed for irritable bowel syndrome (IBS) and other gastrointestinal (GI) disorders.   LX1031 was generated by Lexicon medicinal chemists, and its target was identified by Lexicon as a key control point for the regulation of intestinal serotonin levels.   LX1031 is designed to act locally in the GI tract by reducing the serotonin available for receptor activation, without affecting serotonin levels in the brain or its central nervous system functions. 

The target of LX1031 is tryptophan hydroxylase (TPH), the rate-limiting enzyme for serotonin production found in enterochromaffin cells of the GI tract.  Lexicon scientists discovered that mice lacking the non-neuronal form of this enzyme, TPH1, have virtually no serotonin in the GI tract, but do maintain normal levels of serotonin in the brain.   No adverse effects were observed in these animals across a broad range of medically-relevant parameters, suggesting a favorable safety profile for the mechanism of action of this drug target.

LX1032

LX1032 is an orally-delivered small molecule compound that is being developed for the potential treatment for the GI symptoms associated with carcinoid syndrome.  LX1032 modulates the same target as LX1031, but the two compounds are chemically distinct. LX1032 was internally generated by Lexicon’s medicinal chemists and was specifically designed to be better absorbed into the blood stream and, therefore, capable of reducing serotonin production both inside and outside the GI tract without affecting brain serotonin levels.  LX1032 may provide an additional therapeutic approach for functional and other GI disorders that require systemic regulation of serotonin levels.

LX6171

LX6171 is an orally-delivered small molecule compound that was generated by Lexicon’s medicinal chemists and is being developed to treat disorders characterized by cognitive impairment, such as Alzheimer’s disease, schizophrenia or vascular dementia. LX6171 is a selective and potent inhibitor of a membrane protein, identified by Lexicon that is expressed exclusively in the central nervous system at synaptic vesicles and presynaptic membranes of glutamatergic neurons.