Atrix Laboratories, Inc. announced that Takeda Abbott Pharmaceuticals Products Inc., (TAP), Takeda Chemical Industries, Ltd., and Wako Pure Chemical Industries, Ltd. filed suit against Atrix and its licensee, Sanofi-Synthelabo Inc. alleging that Atrix's Eligard delivery system infringes Takeda's and Wako's US Patent No. 4,728,721. “In our opinion, this patent infringement suit is more related to TAP responding to competitive pressure rather than based on a true infringement issue," said David R Bethune, chairman and chief executive officer at Atrix. "We find the timing of this suit very interesting, coming more than a year after the first Eligard product was approved and marketed. We pay close attention to our proprietary position relating to our drug delivery technologies and work very closely with our patent counsel, Schwegman, Lundberg, Woessner & Kluth, PA. It is our belief that this suit is baseless and is motivated by TAP's concern over losing Lupron market share to Eligard We have no expectations that this suit will disrupt Eligard sales."

Dr. Dick Dunn, principal scientist at Atrix and an inventor of the Atrigel system, said, "Over the last 15 years of developing the Atrigel drug delivery system used in Eligard and other products, we have paid very close attention to our intellectual property rights. We believe that we have a strong patent position and that patent position is the core of a strong developmental program."

The Eligard products use Atrix's proprietary Atrigel sustained-release drug delivery technology. The liquid Eligard products are injected subcutaneously with a small gauge needle forming a solid implant in the body that slowly releases leuprolide, as the implant is bioabsorbed. Eligard 7.5mg, 22.5mg and 30mg products for advanced prostate cancer are currently marketed in the US by Sanofi-Synthelabo, Inc. The Atrigel technology and related products are covered under multiple issued patents including the latest US Patent No. 6,565,874 issued on May 20th, 2003, which effectively provides patent protection for the Eligard prostate cancer products franchise to 2018.