XenoPort and GSK end Horizant collaboration

XenoPort and GSK have mutually agreed to terminate their collaboration on Horizant, a drug approved for the treatment of restless legs syndrome and post-shingles nerve pain.

XenoPort and GlaxoSmithKline (GSK) have agreed to terminate their collaboration on Horizant (gabapentin enacarbil) extended-release tablets for the treatment of restless legs syndrome.

GSK held commercialisation rights and certain development rights for Horizant in the US, but lost faith in the collaboration after the drug failed to live up to sales expectations.

The companies have now mutually agreed to terminate their collaboration, with GSK returning the rights to XenoPort during a transition period ending April 30th 2013.

In a statement, XenoPort acknowledged that GSK had "fulfilled its contractual obligations on the development, manufacturing and commercialisation of Horizant".

GSK will continue to commercialise, promote, manufacture and distribute Horizant during the transition period, during which time XenoPort will not receive any revenue or incur any losses from sales.

Following the end of the transition period, the US pharmaceutical company will be responsible for any further development, manufacturing and commercialisation of the drug.

Earlier this year, XenoPort and GSK obtained US Food and Drug Administration approval for Horizant to be marketed as a treatment for nerve pain following shingles.