WATSON, GSK REACH SETTLEMENT OVER WELLBUTRIN XL PATENT LITIGATION

Watson Pharmaceuticals has agreed to license its bupropion hydrochloride absorption method patent for $35 million as part of a settlement to resolve patent litigation regarding GlaxoSmithKline's (GSK) Wellbutrin XL.

GSK will make the one-time payment to Andrx, recently acquired by Watson, in exchange for a royalty-bearing license to use the generic firm's '708 "technology" patent.

Andrx had sued GSK in the U.S. District Court for the Southern District of Florida, saying the brand drug infringed on the generic firm's patent covering a once-daily, 150-mg formulation of buproprion hydrochloride.

Terms of the agreement were not made public; however, the company plans to discuss the agreement in detail at a later date, Watson representative Patty Eisenhaur said. The settlement allows GSK to continue selling its brand drug, she added.

Several generic companies have filed to market generic buproprion hydrochloride and terms of this agreement may play a role in bringing their generic versions to market, according to Eisenhaur.

"Watson does have outstanding litigation related to other generic firms," she said, pointing to Anchen Pharmaceuticals, which won final FDA approval to be the first to market generic bupropion hydrochloride extended release in 150- and 300-mg tablets.

Representatives at Biovail, the Canadian drug firm that produces Wellbutrin XL, distributed by GSK, had no comment.