SANTA CLARA, Calif., March 29 /PRNewswire-FirstCall/ -- XenoPort, Inc. announced today that additional data from the company’s Phase 2b clinical trial of XP13512 for the treatment of Restless Legs Syndrome, or RLS, will be presented by Clete A. Kushida, M.D., Ph.D., at the American Academy of Neurology (AAN) Meeting, April 1-8, 2006 in San Diego, California. Dr. Kushida is an Associate Professor at Stanford University Medical Center and Director of the Stanford Center for Human Sleep Research.
The oral presentation on Sunday, April 2 at 3:15 p.m. will report on the efficacy, safety and tolerability of a sustained-release formulation of XP13512 in the treatment of RLS. The clinical trial demonstrated that XP13512 provided statistically significant and clinically relevant benefits to patients with RLS when dosed at 1200 mg once per day for 14 days. The trial was a multi-center, randomized, double-blind, placebo-controlled Phase 2b clinical trial that enrolled 95 patients diagnosed with RLS using the International RLS Study Group diagnostic criteria. Patients were randomized to one of three treatment groups: placebo, 600 mg of XP13512 or 1200 mg of XP13512, all dosed once per day at 5:00 p.m. with food. The primary endpoint of the clinical trial was improvement in the International Restless Legs Syndrome (IRLS) scale score. Treatment with 1200 mg of XP13512 was associated with a highly statistically significant improvement (p<0.0001) in the IRLS scale score compared with placebo at the end of 14 days of treatment. A statistically significant reduction in the IRLS scale score was also observed after one week of treatment. Additional secondary endpoints of the clinical trial were the improvement in both Patient and Investigator Clinical Global Impression of Change, or CGI, scales, which were used to assess overall patient improvements. Treatment with 1200 mg of XP13512 was associated with statistically significant improvements in both CGI scales compared to placebo. Treatment with 1200 mg of XP13512 was also associated with statistically significant improvements compared with placebo in a number of subjective measures of sleep, including overall quality of sleep, the number of awakenings per night due to RLS symptoms and the number of hours awake per night due to RLS symptoms. Finally, treatment with 1200 mg of XP13512, compared to placebo, was associated with a statistically significant reduction in the severity of RLS symptoms in the evening (8 p.m. to midnight) as measured using a 24-hour RLS symptom diary on the final day of treatment. Clinical effects measured by the above endpoints in patients treated with 600 mg of XP13512 were not statistically different from patients treated with placebo. XP13512 was generally well tolerated. There were no serious adverse events.
According to the National Institute of Neurological Disorders and Stroke, RLS is the third largest sleep disorder. Exact prevalence rates are not known, but a study published in the May 2004 issue of Sleep Medicine indicates that 2.4 percent of patients visiting primary care physicians in the United States and four European countries suffer from RLS symptoms severe enough to disrupt their quality of life. Patients that suffer from this common, yet under-diagnosed neurological disorder, experience an irresistible urge to move their legs. This urge is usually accompanied by unpleasant sensations of burning, creeping, tugging or tingling inside the patients’ legs, ranging in severity from uncomfortable to painful. These RLS-related symptoms typically begin or worsen during periods of rest or inactivity, particularly when lying down or sitting, and may be temporarily relieved by movement such as walking or massaging the legs. Symptoms often worsen at night, and disturbed sleep is a common result of RLS. Left untreated, RLS may cause exhaustion, daytime fatigue, inability to concentrate and impaired memory.
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 track. 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. Additional Phase 1 clinical trials with a sustained-release formulation of XP13512 have demonstrated that, compared to equivalent doses of Neurontin, XP13512 produced higher levels of gabapentin in the blood for a longer period of time. XP13512 has successfully completed a Phase 2 clinical program for the treatment of RLS and has commenced a Phase 3 clinical program in RLS patients. In addition to RLS, XP13512 has been shown in a Phase 2a clinical trial to be effective for the management of post-herpetic neuralgia. 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 and the timing thereof; 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, +1-408-616-7220, or ir@XenoPort.com
Web site: http://www.xenoport.com//
