Regulatory Update: GSK and XenoPort Submit Supplemental New Drug Application to FDA for Horizant(TM) in Postherpetic Neuralgia

LONDON & RESEARCH TRIANGLE PARK, N.C. & SANTA CLARA, Calif., Aug 09, 2011 (BUSINESS WIRE) -- GlaxoSmithKline /quotes/zigman/146635/quotes/nls/gsk GSK -3.35% /quotes/zigman/263563 UK:GSK -3.06% and XenoPort, Inc. /quotes/zigman/91976/quotes/nls/xnpt XNPT +1.42% announced today that a supplemental New Drug Application (sNDA) has been submitted to the U.S. Food and Drug Administration (FDA) requesting approval of Horizant(TM) (gabapentin enacarbil) Extended-Release Tablets for the management of postherpetic neuralgia (PHN) in adults. The sNDA has been submitted to the FDA by GSK.

Notes to Editors

Horizant is not approved or licensed anywhere in the world for PHN. For information about the current licensed indication for Horizant, which is in the United States only, please visit for full Prescribing Information and Medication Guide.

About GlaxoSmithKline

GlaxoSmithKline is one of the world's leading research-based pharmaceutical and healthcare companies and is committed to improving the quality of human life by enabling people to do more, feel better and live longer. For more information, visit GlaxoSmithKline at .

About XenoPort

XenoPort is a biopharmaceutical company focused on developing a portfolio of internally discovered product candidates that utilize the body's nutrient transport mechanisms to improve the therapeutic benefits of existing drugs. Horizant is XenoPort's first approved product. GlaxoSmithKline holds commercialization rights and certain development rights for gabapentin enacarbil in the United States. Gabapentin enacarbil is also being developed in partnership with Astellas Pharma Inc. for the potential treatment of Restless Legs Syndrome in Japan. XenoPort holds all other world-wide rights and has co-promotion and certain development rights to gabapentin enacarbil in the United States. XenoPort's pipeline of product candidates includes potential treatments for patients with neuropathic pain, spasticity and Parkinson's disease. To learn more about XenoPort, please visit the Web site at .