Impax Laboratories Inc. vs. Aventis Pharmaceuticals Inc. (Riluzole)

October 3, 2008, In an appeal from a District Court's remand decision holding ’940 patent does not enable a person of ordinary skill in the art to treat ALS with riluzole and therefore does not anticipate claims 1-5 of the ’814 patent, the Federal Circuit affirmed the District Court's finding
the ’940 patent is not an enabling prior art reference and that it does not anticipate claims 1-5 of the ’814 patent.

The whole judgement can be read here.

Other links related to this post are as follows:
http://www.patentdocs.net/patent_docs/2006/12/impax_laborator.html
http://www.orangebookblog.com/2006/12/federal_circuit.html

A breif history of the case.

Impax Laboratories, Inc. (Impax) filed an ANDA with the FDA pursuant to 21 U.S.C. 355(j) seeking approval to market generic riluzole tablets on May 16, 2001. On June 25, 2002, Impax sued Aventis in the district of Delaware for a declaratory judgment that Impax did not infringe, induce infringement of, or contribute to the infringement of the ’814 patent. In its suit, Impax alleged that the ’814 patent was invalid and unenforceable.

After a bench trial, the district court determined that Impax did not prove that the ’814 patent was unenforceable due to inequitable conduct nor show that claims 1-5 were anticipated by prior art. Impax Labs., Inc. v. Aventis Pharms. Inc., 333 F. Supp. 2d 265 (D. Del. 2004). On March 16, 2005, the court entered final judgment against Impax.

Impax appealed that decision. This court affirmed-in-part, vacated-in-part, and remanded to the district court. Impax Labs., Inc. v. Aventis Pharms. Inc., 468 F.3d 1366, 1384 (Fed. Cir. 2006). On remand, the trial court examined the asserted prior art, the ’940 patent, for evidence that it enables the use of riluzole to treat ALS and thus qualifies as enabling prior art. Impax Labs., Inc. v. Aventis Pharms. Inc., 496 F. Supp. 2d 428, 433 (D. Del. 2007).

In the event that it qualifies as enabling prior art, the trial court also received the opportunity to determine if the disclosure anticipates claims 1-5 of the ’814 patent. Addressing those questions, the district court determined that the ’940 patent does not enable a person of ordinary skill in the art to treat ALS with riluzole and therefore does not anticipate claims 1-5 of the ’814 patent. Id. Impax timely appealed the district court’s remand decision to this court.