XenoPort initiates XP23829 Phase 2 clinical trial in patients with psoriasis

XenoPort, Inc. (Nasdaq: XNPT) announced today that it has initiated a Phase 2 clinical trial of XP23829, its proprietary investigational next-generation fumaric acid product candidate. The trial is a multi-center, randomized, double-blind, placebo-controlled study designed to assess the efficacy and safety of XP23829 as a potential treatment of patients with moderate-to-severe chronic plaque-type psoriasis.

Richard Kim, M.D., XenoPort's chief medical officer, stated, "We are excited to take this next step in the advancement of the development of XP23829. From this Phase 2 trial, we hope to further our understanding of the efficacy, safety and tolerability of XP23829. In addition, the study is designed to generate information on the effect of dose and treatment duration on potential reduction in psoriatic lesions and modulation of sub-populations of blood immune cells. Based on historical enrollment rates of psoriasis studies conducted in the U.S., we expect top-line results of the trial in the third quarter of 2015."

XenoPort expects to enroll approximately 200 subjects in this trial, which is being conducted in the United States. The study will include a screening and washout phase of up to four weeks, a 12-week treatment phase and a four-week post-treatment phase. Eligible study subjects will be randomized to placebo or one of three treatment arms of XP23829: 400 mg or 800 mg once daily or 400 mg twice daily. The primary endpoint of the study will examine the percent change in Psoriasis Area and Severity Index (PASI) score from baseline at the end of week 12. Secondary endpoints will include the proportion of subjects who achieve a reduction of 75% or greater from baseline in PASI (PASI-75) score and subjects who achieve a Static Physicians Global Assessment (sPGA) score of "clear" or "almost clear."

Ronald W. Barrett, Ph.D., XenoPort's chief executive officer, further commented, "Fumaric acid ester drugs have been previously shown to be effective in psoriasis, although there are no products in the class that are approved by the U.S. Food and Drug Administration (FDA) for this indication. We believe that this trial will begin to define the distinguishing attributes of XP23829 as a potential best-in-class drug. These attributes could potentially include convenient once-a-day dosing, reduced flushing and gastrointestinal side effects and possibly more rapid onset and increased magnitude of efficacy. We believe that the results from this trial, if positive, could allow advancement of XP23829 directly into Phase 3 studies as a potential treatment for psoriasis. In addition, based on the strong correlation of results in psoriasis and relapsing forms of multiple sclerosis (MS) observed for other fumaric acid based drugs, we believe that this study could also form a basis for moving XP23829 into Phase 3 studies as a potential treatment for relapsing forms of MS."

Source: XenoPort, Inc.