Idenix Pharma Drops After Faltering in Gilead Patent Dispute

Idenix Pharmaceuticals Inc. (IDIX), a maker of drugs for viral diseases, fell the most in six months after losing a decision over whether it or Gilead Sciences Inc. (GILD) was first to request a patent related to hepatitis C treatments.

Idenix fell 10 percent to $4.13 at 10:35 a.m. New York time, after falling as much as 15 percent in the largest intraday decrease since Sept. 19. The U.S. Patent and Trademark Office determined that Idenix’s application for compounds used to treat hepatitis C was filed later than Gilead’s, Idenix said in a statement on March 22.

The patent office’s determination makes Foster City, California-based Gilead the “senior party” in the case and Idenix, based in Cambridge, Massachusetts, the “junior party,” Idenix said. The agency will next determine which company was the first to invent.

Idenix said it doesn’t believe the application at issue is relevant to any of its compounds under development. Idenix plans to begin the second of three phases of clinical trials on one of its hepatitis C therapies, IDX719, in the first half of this year.

Idenix fell 55 percent in the 12 months through last week.

To contact the reporter on this story: Anna Edney in Washington at

To contact the editor responsible for this story: Reg Gale at

Press spacebar to pause and continue. Press esc to stop.

Bloomberg reserves the right to remove comments but is under no obligation to do so, or to explain individual moderation decisions.

Please enable JavaScript to view the comments powered by Disqus.