GlaxoSmithKline plc (GSK) has entered into an agreement to divest full commercial rights of Wellbutrin XL in the United States to Biovail International Laboratories SRL, a subsidiary of Biovail Corporation, for $510 million (£340 million). The agreement is subject to Hart-Scott-Rodino regulatory clearance in the US.

Generic competition to Wellbutrin XL began at the end of 2006 for the 300mg tablet and during the second quarter of 2008 for the 150mg tablet. US sales of Wellbutrin XL in the first quarter of 2009 were £45 million (-70%).

"We are actively reshaping our US business and managing the transition occurring in our product portfolio," said Deirdre Connelly, president, North American Pharmaceuticals, GlaxoSmithKline. "This transaction is one of a series of actions we are taking to maximise the value of our current assets and to enable us to resource and invest in new products and upcoming launches."

Under the terms of the agreement, GSK will transfer the US NDA and license the Wellbutrin XL trademark to Biovail for use in the US. GSK will retain existing rights to Wellbutrin XL (excluding Canada) for countries outside the US. Sales of Wellbutrin XL outside the US were £7 million in the first quarter of 2009.

GSK expects to record a pre-tax gain of approximately £340 million in Other Operating Income as a result of this divestment. The company now expects the combined total of Other Operating Income and profit on disposal of interests in associates to be around £700 million in 2009.

Wellbutrin XL (bupropion hydrochloride extended-release tablets) is indicated for the treatment of major depressive disorder and seasonal affective disorder. It was developed by Biovail and has been distributed by GSK in the United States since September 2003.