´Teaching Away´ Requires Clear Discouragement from Claimed Combination

The U.S. Court of Appeals for the Federal Circuit found "clear error" in a district court ruling that a patent directed to an ophthalmic anti-inflammatory drug formulation, marketed by Allergan, Inc. (Allergan) under the brand name ACULAR^®, was valid and not an obvious variation of earlier known compounds. Syntex (U.S.A.) LLC v. Apotex, Inc., Case No. 04-1252 (Fed. Cir. May 18, 2005) (Gajarsa C.J.; Prost, C.J. concurring).

Apotex, Inc. (Apotex) appealed from the final judgment of the district court, which, after a bench trial, held the patent owned by Syntex LLC (Syntex) not invalid, enforceable and infringed by Apotex's Abbreviated New Drug Application (ANDA). The patent claims a formulation for sterile, preserved eye drops to treat eye inflammation, such as that caused by conjunctivitis or eye surgery, and teaches combining a nonsteroidal anti-inflammatory drug (NSAID) such as ketoralac tromethamine (KT) and a quaternary ammonium preservative such as benzalkonium chloride (BAC)