SANTA CLARA, Calif., May 4 /PRNewswire-FirstCall/ -- XenoPort, Inc. announced today that additional data from the company’s Phase 2a clinical trial of XP13512 for the treatment of post-herpetic neuralgia, or PHN, will be presented by Miroslav Backonja, M.D., at the American Pain Society Annual Meeting, May 3-6, 2006 in San Antonio, Texas. Dr. Backonja is an Associate Professor of Neurology, Anesthesiology and Rehabilitation Medicine at the University of Wisconsin Hospital and Clinics, Madison, Wisconsin.
The oral presentation on Thursday, May 4, at the 2:00 p.m. session of the American Pain Society provides an analysis of a Phase 2a randomized, double-blind, placebo-controlled study in which 101 PHN patients were first treated with 600 mg Neurontin three times daily, followed by treatment with 1200 mg XP13512 or placebo twice daily for 14 days. The study analyzed gabapentin plasma pharmacokinetic profiles at the end of the Neurontin treatment period and at the end of the XP13512 and placebo treatment period. Daily pain scores (11-point Likert scale) were determined as the average of morning and evening pain score. Mean Pain Scores, or MPS, were calculated as the mean of the daily pain score over the last seven days of treatment.
Pharmacokinetic analysis showed that, despite being administered at a lower molar daily dose (2400 mg XP13512 can maximally release 1248 mg gabapentin), XP13512 produced a mean increase of 17% in the average plasma concentration of gabapentin compared to that produced by Neurontin in the same patient (p=0.005). Analysis of all patients in the XP13512 treatment arm indicated that MPS was lower at the end of XP13512 treatment compared to the end of Neurontin treatment (difference=-0.4; p=0.0454). A subgroup of patients (36% of total) had an increased average plasma concentration of gabapentin of greater than 30% during XP13512 treatment compared to Neurontin treatment. The improvement in MPS from the end of Neurontin treatment to the end of XP13512 treatment was more pronounced in this group (difference=-0.9; p=0.0126) and was not seen in a subgroup of patients whose average gabapentin concentration was less than 20% different while on XP13512 compared to Neurontin (difference=-0.2; p=0.4841). XP13512 was well tolerated in this study.
About XP13512
XP13512 is a Transported Prodrug of gabapentin, a drug that has been sold by Pfizer Inc as Neurontin since 1993 and is currently sold as a generic drug by a number of companies. XP13512 utilizes high-capacity transport mechanisms to be well absorbed in the small and large intestines and is designed to then rapidly convert to gabapentin upon absorption from the gastrointestinal tract. Besides gabapentin, the metabolic breakdown products of XP13512 are molecules that have undergone extensive safety testing and are found naturally in mammals and in food. Phase 1 clinical trials in healthy volunteers have demonstrated that, in contrast to Neurontin, oral administration of XP13512 produces dose-proportional blood levels of gabapentin across a broad range of doses. XP13512 has successfully completed a Phase 2 clinical program for the treatment of Restless Legs Syndrome, or RLS, and has commenced a Phase 3 clinical program in RLS patients. XP13512 has been well tolerated in all clinical trials completed to date.
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. In addition to the clinical trials that have been completed for XP13512, XenoPort has completed two Phase 1 clinical trials of XP19986, a Transported Prodrug of R-baclofen. These trials demonstrated that a prototype formulation of XP19986 was suitable for twice-a-day dosing and was well tolerated with few adverse events at the doses expected to be used in future clinical trials. XenoPort has commenced a Phase 2a clinical trial of XP19986 in gastroesophageal reflux disease, or GERD, patients.
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 our future clinical development programs for XP13512 and XP19986; the therapeutic and commercial potential of XP13512 and XP19986; future clinical development plans; and our future clinical trials. 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 “believes,” “anticipates,” “plans,” “expects,” “will,” “intends,” “potential” 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 ability of the company to successfully conduct clinical trials for XP13512 and XP19986; the uncertainty of the FDA approval process and other regulatory requirements; and the therapeutic and commercial value of the company’s compounds. These and other risk factors are discussed under the heading “Risk Factors” in our Annual Report on Form 10-K for the year ended December 31, 2005, filed with the Securities and Exchange Commission on March 17, 2006. 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.
NOTE: XenoPort and Transported Prodrug are U.S. trademarks of XenoPort, Inc.
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XenoPort, Inc.
CONTACT: Jackie Cossmon of XenoPort, Inc., +1-408-616-7220, orir@XenoPort.com
Web site: http://www.xenoport.com//
