SANTA CLARA, Calif., June 20 /PRNewswire-FirstCall/ -- XenoPort, Inc. announced today that data from the company’s previously reported Phase 2a 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 SLEEP 2006 20th Anniversary Meeting of the Associated Professional Sleep Societies Meeting in Salt Lake City, Utah on Wednesday, June 21 at 9:45 a.m. MDT. Dr. Kushida is an Associate Professor at Stanford University Medical Center and Director of the Stanford Center for Human Sleep Research.
The oral presentation will report results of a Phase 2a clinical trial demonstrating that XP13512 was effective in reducing symptoms and sleep disturbances in RLS patients. The trial was a multi-center, randomized, double-blind, placebo-controlled, cross-over trial that evaluated 34 patients for two weeks with placebo or 1800 mg of XP13512 (600 mg at 5:00 p.m.; 1200 mg one hour before bed) with a one week wash-out period between treatments. The primary endpoint was the change from baseline in International Restless Legs Scale (IRLS) total score at week two. Secondary endpoints included: the change in IRLS total score at week one; investigator Clinical Global Impression (CGI) of Change and subjective measures of sleep at the end of two weeks. Polysomnography (PSG) and Suggested Immobilization Tests (SIT) were conducted at baseline and at the end of each treatment period.
The clinical trial showed that, compared to placebo, treatment with XP13512 significantly improved the IRLS score at the end of two weeks (change from baseline = -12.1 vs. -1.9), investigator CGI, the number of awakenings per night due to RLS symptoms and the number of hours awake per night due to RLS symptoms (all p<0.0001). XP13512 treatment led to significant reductions in the Leg Discomfort Score during SIT. Compared to placebo, XP13512 treatment statistically significantly increased PSG-determined total sleep time (+25.2 min; p=0.0317) and Stage 3/4 sleep (+21.3 min; p=0.0002), and reduced the time awake after persistent sleep onset (-28.2 min; p=0.0009). XP13512 reduced the number of periodic limb movements with arousals (PLMA) (46.3 for placebo; 29.3 for XP13512; p=0.0082) and awakenings (5.9 for placebo, 3.8 for XP13512; p=0.0172). XP13512 was generally well tolerated. There were no serious adverse events. The most common side effects were somnolence and dizziness.
About RLS
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. 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 into the body. 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 for XP13512 described above, XenoPort has also completed two Phase 1 clinical trials of XP19986, a Transported Prodrug of R-baclofen, and reported preliminary positive results of a Phase 2a clinical trial of XP19986 in 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 the therapeutic and commercial potential of XP13512; 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 most recent public filings with the Securities and Exchange Commission. 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.
XNPT2C
XenoPort, Inc.
CONTACT: Jackie Cossmon of XenoPort, +1-408-616-7220, or ir@XenoPort.com
Web site: http://www.xenoport.com//
