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XenoPort Announces Presentation of Preclinical Data for Acamprosate Prodrug at Fragile X Syndrome Conference

SANTA CLARA, Calif.--(BUSINESS WIRE)--Jul 23, 2010 - XenoPort, Inc. (Nasdaq:XNPT) announced today that it has discovered a novel prodrug that has the potential to improve significantly the blood concentration of acamprosate compared with the currently approved formulation of acamprosate. Preclinical data on this new product candidate will be presented tomorrow at the National Fragile X Foundation's 12th International Fragile X Conference in Detroit, Michigan.

Acamprosate calcium has been marketed under the trade name Campral since 2004 for the maintenance of abstinence in alcoholics. A recently published open-label study of acamprosate calcium in three adult Fragile X syndrome patients with co-occurring autism spectrum disorder was conducted by Craig A. Erickson, M.D., Assistant Professor of Psychiatry at the Indiana University School of Medicine. This study showed evidence of therapeutic benefit in all patients as measured by the Clinical Global-Impression of Improvement Scale. Treatment with acamprosate calcium was also associated with reported improvement in linguistic communication. Two of the three patients experienced gastrointestinal (GI) disturbances, which affected the dosing regimen and led to temporary drug discontinuation in one patient.

Poor absorption from the GI tract is thought to contribute to GI disturbance associated with oral dosing of acamprosate calcium. Low oral bioavailability (~10%) and variable exposure may also limit its efficacy.

Preclinical trial results that will be presented tomorrow indicate that oral dosing of XenoPort's new acamprosate prodrug has the potential to significantly improve blood concentrations of acamprosate compared with oral dosing of acamprosate calcium. In addition, efficient absorption of the prodrug from the colon was observed and suggests that an extended-release oral formulation would be possible. XenoPort's prodrug of acamprosate could offer the potential for meaningful improvements over oral acamprosate calcium that may include a decrease in GI disturbance, reduced dosing frequency and more consistent (and potentially higher) blood levels of acamprosate.

Ronald W. Barrett, Ph.D., chief executive officer of XenoPort, stated, “Further studies of XenoPort's acamprosate prodrug are required, but we are hopeful that improved bioavailability and tolerability could prove useful in treating the symptoms of patients with Fragile X syndrome.” Barrett continued, “Our financial resources are limited and prevent immediate advancement of this preclinical product candidate. However, we are exploring options for further development, including corporate partners or grants from private or public institutions.”

XenoPort has filed patent applications directed to the acamprosate prodrug's composition of matter, methods of synthesis and uses in the United States and other jurisdictions.

About Fragile X Syndrome

Fragile X syndrome is the most common form of inherited intellectual and developmental disabilities. Fragile X syndrome is caused by a large change (also called a full mutation) in a single gene called the Fragile X Mental Retardation 1 (FMR1) gene. The FMR1 gene is required for making Fragile X Mental Retardation Protein (FMRP), which the body needs for the brain to develop. The full mutation to the FMR1 gene causes little or no FMRP to be synthesized by the body. When FMRP is missing, or present in only small quantities, it results in Fragile X syndrome.

In the United States, it is estimated that approximately 75,000 people carry a full mutation of the FMR1 gene. There are currently no drugs approved specifically for the treatment of Fragile X syndrome or its causes.

About XenoPort

XenoPort, Inc. is a biopharmaceutical company focused on developing a portfolio of internally discovered product candidates that utilize the body's natural nutrient transport mechanisms to improve the therapeutic benefits of existing drugs. XenoPort is developing its lead product candidate in collaboration with Astellas Pharma Inc. and GlaxoSmithKline. XenoPort's product candidates are being studied for the potential treatment of restless legs syndrome, gastroesophageal reflux disease, neuropathic pain, spasticity and Parkinson's disease. To learn more about XenoPort, please visit the web site at

Forward-Looking Statements

This press release contains “forward-looking” statements, including, without limitation, all statements related to XenoPort's future development of its acamprosate prodrug, including its potential use as a treatment of patients with Fragile X syndrome and future collaborations or grant funding opportunities. Any statements contained in this press release that are not statements of historical fact may be deemed to be forward-looking statements. Words such as “could,” “hopeful,” “may,” “possible,” “potential,” “promising,” “suggests,” “would” and similar expressions are intended to identify forward-looking statements. These forward-looking statements are based upon XenoPort's current expectations. Forward-looking statements involve risks and uncertainties. XenoPort's actual results and the timing of events could differ materially from those anticipated in such forward-looking statements as a result of these risks and uncertainties, which include, without limitation, the risks inherent in preclinical and clinical development; XenoPort's dependence on its current and additional collaborative partners; and the uncertain therapeutic and commercial value of XenoPort's preclinical product candidates. These and other risk factors are discussed under the heading “Risk Factors” in XenoPort's Quarterly Report on Form 10-Q for the quarter ended March 31, 2010, filed with the Securities and Exchange Commission on May 10, 2010. XenoPort expressly disclaims any obligation or undertaking to release publicly any updates or revisions to any forward-looking statements contained herein to reflect any change in the company's expectations with regard thereto or any change in events, conditions or circumstances on which any such statements are based.

XenoPort is a registered trademark of XenoPort, Inc.



Contact: XenoPort, Inc.
Jackie Cossmon, 408-616-7220


Posted: July 2010