XENOPORT INITIATES PHASE IIA CLINICAL TRIAL OF XP19986

XenoPort has initiated a Phase IIa clinical trial of XP19986 in patients with gastroesophageal reflux disease. The trial is a multicenter, randomized, double-blind, placebo-controlled, crossover study designed to assess the safety, tolerability and efficacy of XP19986. The clinical trial is intended to test the ability of escalating single doses of a prototype sustained-release formulation of XP19986 to reduce reflux episodes. XenoPort expects to complete the trial in the first half of 2006.

XP19986 is designed to overcome the deficiencies of baclofen, a currently marketed generic drug approved for the treatment of spasticity. Baclofen is a racemic drug (a 50:50 mixture of R- and S-isomers). Studies conducted by third parties have shown that the beneficial therapeutic properties of baclofen are attributable to the R-isomer of baclofen only. Baclofen has a short half-life in blood after oral dosing, which necessitates frequent daily dosing. Absorption of baclofen in the colon is limited, which has prevented the development of a sustained-release formulation that could improve therapy.