Suit Challenging Validity of GlaxoSmithKline’s Paxil Patent Begins

A trial in federal district court to determine the validity of a patent on GlaxoSmithKline's antidepressant Paxil began Feb. 5 in Chicago, the New York Times reports. GSK claims it has exclusive rights to Paxil, which it introduced in 1993, until 2006. However, Canadian generic drug maker Apotex will argue that its version of Paxil, known generically as paroxetine hydrochloride, does not violate that patent because the company is "producing the medicine in a different form." Apotex CEO Bernard Sherman said GSK has "repatented every conceivable form" of Paxil in an effort to block competition. The outcome of the trial is "extremely critical to Glaxo," industry analyst Hemant Shah said. Paxil accounts for approximately $3 billion in worldwide sales, about 10% of GSK's total revenue, the Times reports. The trial is expected to last several weeks, but because of the likelihood of further litigation it is not clear how quickly Apotex would be able to market a generic version of Paxil even if it were to win, the Times reports. Apotex is also challenging other Paxil secondary patents in a case that is expected to go to trial later this year in federal district court in Philadelphia (Abelson, New York Times, 2/5).