Astrazeneca AB v. Hanmi USA, Inc.

Issues of fact preclude summary judgment of anticipation as priority date of reference was disputed; issues of fact precluded summary judgment of indefiniteness, lack of written description and lack of enablement.

October 16, 2012

Robins Kaplan GENERICally Speaking: A Hatch-Waxman Litigation Bulletin

Case Name: Astrazeneca AB v. Hanmi USA, Inc., Civ. No. 11-760 (JAP), 2012 U.S. Dist. LEXIS 123401 (D.N.J. Aug. 30, 2012) (Pisano, J.)

Drug Product and Patent(s)-in-Suit:  Nexium® (esomeprazole); U.S. Patent Nos. 5,877,192 (“the ’192 patent”) and 5,714,504 (“the ’504 patent”)

Nature of the Case and Issue(s) Presented:  Defendants Hanmi, Inc., Hanmi Pharmaceutical Co., Ltd., Hanmi Fine Chemical Co., Ltd. and Hanmi Holdings Co., Ltd. (collectively, “Hanmi”) originally filed five motions seeking summary judgment.  The district court decided two of the motions previously.  This opinion addresses the remaining three:  (i) the asserted claims of the ’192 patent are invalid on the basis of anticipation; (ii) the asserted claims of the ’504 patent are invalid for lack of a written description, indefiniteness, and non-enablement; and (iii) for other reasons, the asserted claims of the ’504 patent are invalid for lack of a written description and non-enablement.  The court denied all three motions.

Why Apotex Prevailed:  In the first motion, Hanmi alleges that the asserted claims are anticipated under § 102(b) because each limitation of those claims is allegedly found in WO ’988, published December 8, 1994.  Hanmi first alleges that the WO ’988 reference is admitted in the ’192 patent to be a prior art reference.  Second, Hanmi argues that the ’192 patent is not entitled to priority to any earlier application and, therefore, the WO ’988 reference is a statutory prior art reference under § 102(b) because it was published more than one year before the effective filing dates of the claims at issue.  Relying on case law holding that patents issued to the same inventive entity are not prior art by admission, and the fact that there existed material disputed facts concerning the priority date sought by the ’192 patent, the court held that Hanmi did not meet its burden on summary judgment.

In its second motion, Hanmi moves for summary judgment of invalidity of claims 1, 2, 4, 6, and 7 of the ’504 patent.  Hanmi’s motion centers on its contention that the claim term “solid state” is indefinite.  In response, AstraZeneca points to an earlier court ruling in a related case that the term “solid state” as used in the claims of the ’504 patent has a plain and ordinary meaning to one or ordinary skill in the art.  The court found that “it has become apparent that adoption of a construction for ‘solid state’ [was] necessary in this case.”  It credited AstraZeneca’s proposed construction as being consistent with the term’s plain and ordinary meaning and adopted it, thereby rejecting Hanmi’s indefiniteness argument.

The asserted claims of the ’504 patent are directed to pharmaceutical formulations comprising a pure solid state alkaline salt of esomeprazole and methods of use for inhibiting gastric acid secretion and treatment of gastrointestinal inflammatory disease.  In its third motion, Hanmi alleges that the patent contains no written description showing that AstraZeneca was in possession of any hydrated form of esomeprazole salt, and, further, that there is no disclosure of how to make any such hydrated form.  According to Hanmi, because AstraZeneca construes the asserted ’504 patent claims to encompass Hanmi’s proposed product, which contains esomeprazole strontium tetrahydrate as the active ingredient, the patent must meet the written description and enablement requirements of § 112 with respect hydrated forms of the alkaline salts of esomeprazole.  The court was not convinced by Hanmi’s arguments because the term “hydrate” is not set forth in the claims.  Moreover, given the dueling expert opinions on the issue, the court found that there existed factual issues that would preclude summary judgment.

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