About XenoPortXenoPort is a biopharmaceutical company focused on developing and commercializing a portfolio of internally discovered product candidates for the potential treatment of neurological disorders. Horizant ® (gabapentin enacarbil) Extended-Release Tablets is approved in the United States for the treatment of moderate-to-severe primary restless legs syndrome (RLS) in adults and for the management of postherpetic neuralgia in adults. GlaxoSmithKline holds commercialization rights and certain development rights for Horizant in the United States. Regnite ® (gabapentin enacarbil) Extended-Release Tablets is approved for the treatment of RLS in Japan. Astellas Pharma Inc. holds all development and commercialization rights for Regnite in Japan and five other Asian countries. XenoPort holds all other world-wide rights and has co-promotion and certain development rights to gabapentin enacarbil in the United States. XenoPort’s pipeline of product candidates includes potential treatments for patients with spasticity, Parkinson’s disease and RRMS. To learn more about XenoPort, please visit the web site at www.XenoPort.com. Forward-Looking Statements This press release contains “forward-looking” statements, including, without limitation, all statements related to the clinical development of XP23829 and the timing and results thereof; the potential suitability of XP23829 as a treatment for RRMS and/or psoriasis; and the therapeutic and commercial potential of XenoPort’s clinical product candidates. 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 “believe,” “possible,” “potential,” “will,” 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, risks related to the uncertain results and timing of clinical trials and other studies; XenoPort’s ability to successfully conduct clinical trials in the anticipated timeframes, or at all; XenoPort’s dependence on its current and additional collaborative partners; the availability of resources to develop XenoPort’s product candidates; and the uncertain therapeutic and commercial value of XenoPort’s 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, 2012, filed with the Securities and Exchange Commission on May 8, 2012. 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.