GlaxoSmithKline (NYSE:GSK) and XenoPort, Inc. (Nasdaq:XNPT) Wednesday
received a Complete Response letter from the U.S. Food and Drug
Administration (FDA) regarding the New Drug Application (NDA) for
Horizant™ (gabapentin enacarbil) Extended-Release Tablets, an
investigational non-dopaminergic treatment for moderate-to-severe
primary Restless Legs Syndrome (RLS).
A Complete Response letter is issued by the FDA’s Center of Drug
Evaluation and Research when the review of a file is completed and
questions remain that preclude the approval of the NDA in its current
form. GSK and XenoPort are currently evaluating the Complete Response
letter, in which the FDA indicated that a preclinical finding of
pancreatic acinar cell tumors in rats was of sufficient concern to
preclude approval of Horizant for RLS at this time. FDA
acknowledged that similar findings were known for gabapentin at the time
of its approval for refractory epilepsy, but concluded that the
seriousness and severity of refractory epilepsy justified the potential
risks. The companies are assessing the appropriate next steps and will
be communicating with FDA.
The NDA was submitted to the FDA on January 9, 2009.
SOURCE GlaxoSmithKline and XenoPort