XenoPort’s $23 million milestone fee depends on acceptance of application by the FDA.
GlaxoSmithKline and XenoPort are pulling the NDA for a restless leg syndrome (RLS) therapy after the FDA asked that certain data be reformatted. The decision delays $23 million in milestone payments to XenoPort from GSK and Astellas Pharma.
XenoPort’s shares fell about 19% to open trading at $33.20. The news had no noticeable effect on GSK’s or Astellas’ stock price.
GSK says that it will review other trial data sets as well. The firm plans to resubmit the NDA once this work is complete.
Solzira™ has been developed as a treatment for moderate-to-severe primary RLS. It is designed to improve upon the pharmacokinetics of gabapentin by taking advantage of high-capacity transport mechanisms in the gastrointestinal tract to improve absorption.
Astellas owns rights in Japan and five Asian countries, while GSK gained rights for the rest of the world in a deal valued at $640 million. The $23 million milestone is associated with the acceptance by the FDA of the NDA for Solzira. The original agreement called for $65 million in milestones for development activities leading up to the NDA filing for RLS, up to $210 million in other potential development- and regulatory-related payments, and up to $290 million in potential sales milestones based on successful commercialization for RLS and neuropathic pain.
