GlaxoSmithKline and XenoPort, Inc. have submitted a NDA to the FDA requesting approval of Solzira Extended Release Tablets for the treatment of moderate-to-severe primary Restless Legs Syndrome (RLS). RLS affects an estimated 12 million people in the U.S. and can result in symptoms that disrupt sleep and impact daily activities.     The NDA submission is based on a Phase III clinical development program for Solzira in RLS patients, including data from two randomized, double-blind, placebo-con...