Xytis, Inc. announced it has received permission from the FDA to conduct Phase I single and multiple ascending dose studies with its novel positive allosteric modulator, XY4083. Xytis plans to begin these studies in early 2009.

Allosteric modulation is the safest and most natural way to enhance the activity of a neuroreceptor,” stated Vincent F. Simmon, Ph.D., President and CEO of Xytis. “There are two alternatives for enhancing activity of a neuroreceptor; binding at the normal ligand binding site, or binding at a distant site. Classically, direct agonist drugs bind to the neurotransmitter binding site and provide a constant, but non-physiological, activated receptor. Allosteric modulators bind to an accessory site on the receptor, but do not activate it on their own, instead relying on the normal neurotransmitter to activate the receptor. A common problem with direct agonist drugs is that they induce tolerance, thus resulting in a loss of effectiveness of the drug or agonist over time. This mechanism is well known for CNS drugs; benzodiazepines are the most prescribed psychiatric medications and are positive allosteric modulators.”

The Alpha-7 nicotinic acetylcholine receptor (Alpha-7nAChR) is a relatively recent target for new drug development; there are no approved drugs that work through this receptor subtype, although there are several in clinical development. A variety of animal behavioral studies, as well as early results in Phase II clinical trials demonstrate that enhancement of activity at the Alpha-7nACh receptor leads to increased cognition and attention. The therapeutic indications these drugs target include Alzheimer’s disease, cognitive impairment due to schizophrenia and aging, and attention deficit hyperactivity disorder.

About Xytis:
Xytis, Inc. is a privately held discovery and development biopharmaceutical company focusing on innovative CNS drug candidates. The company has received funding from Atlas Venture, Sanderling Ventures, CDC Innovation, and Ventech. Xytis has a rich portfolio of proprietary preclinical compounds that are novel, highly selective allosteric modulators of nicotinic acetylcholine receptors (nAChRs), GABA-A receptors and other well-validated CNS targets. The Company’s other clinical stage drugs include Anatibant (XY2405) and Neboglamine (XY2401). A Phase IIa safety study with Anatibant has recently been completed, demonstrating that it is safe and well-tolerated in patients with traumatic brain injury. Three Phase I studies in healthy volunteers have been completed with Neboglamine. Xytis’ drugs are currently in early development or investigational clinical trials and have not been approved for the treatment of any disease