Issue 06/63 | November 21, 2006
Rasmusson Redux: §102 References Need Not Demonstrate Utility to be Enabling for Purposes of Anticipation

The "use" requirement of §112 requires a demonstration of utility to be enabling. In contrast, an anticipatory reference under §102 is presumed to be enabled without a showing of actual utility or efficacy. Those seeking to distinguish anticipatory references should be mindful of the different standards for disclosure of utility under Sections 102 and 112.

In Impax Labs., Inc. v. Aventis Pharmaceuticals, Inc., No. 05-1313 (Fed. Cir. Nov. 20, 2006), the federal circuit affirmed a district court judgment that Aventis' '824 patent was not unenforceable based on inequitable conduct, but reversed the finding of no anticipation based on the erroneous determination that a prior art reference was not enabling.

Aventis' '814 patent is directed to riluzole, a drug used in the treatment of ALS (Lou Gherig's disease). Because the '814 patent was not listed in the Orange Book at the time of Impax's ANDA, Impax sought a declaratory judgment of unenforceability (based on inequitable conduct) and anticipation. The district court rejected each claim. First, the district court held that unsubmitted test data comparing riluzole to three other antiglutamate agents were not inconsistent with Aventis' representations regarding submitted test data showing riluzole's superiority over two other antiglutamate agents. The court also concluded that the unsubmitted comparative data did not produce results that indicated effectiveness in treating ALS because of the data obtained, the procedures used, and the fact that the later-submitted clinical trial evidence was more valuable. The district court also found that although two prior art references disclosed riluzole generically, neither reference was enabling for efficacy, and thus neither could be anticipatory.

On appeal, the federal circuit affirmed the district court's judgment that there was no inequitable conduct. There was no evidence that the withheld comparative test data established by itself or in combination with other information a prima facie case of unpatentability of a claim, and the district court correctly recognized that the unsubmitted comparative data did not show any of the antiglutamate agents tested was effective in treating ALS. Nor was there sufficient evidence of intent to deceive.

However, the court reached a different conclusion regarding anticipation. Aventis' prior art '940 patent claimed priority from its published '624 French application, both of which disclosed generic Formula I, which included riluzole. The '940 patent recited the utility of the compounds of Formula I for treating ALS and provided disclosure for their effective administration. The district court held that the '940 patent did not anticipate the '814 patent because of the large number of compounds included within Formula I and the lack of detail or guidance suggesting that riluzole in particular would be effective in treating ALS. But the federal circuit disagreed based on Rasmusson, which stated that a prior art reference need not demonstrate utility in order to serve as an anticipating reference under §102. The district court thus erred in concluding that the '940 patent was not enabling because there was no evidence that it would be "effective" in the treatment of ALS: "[p]roof of efficacy is not required for a prior art reference to be enabling for purposes of anticipation."

Please visit http://media.aplf.org/resources/alert2006-63/Impax.pdf for a copy of the case for your reference.

To discuss these topics further, please feel free to contact the author, Michael R. Dzwonczyk (mdzwonczyk@sughrue.com), at Sughrue Mion, PLLC in Washington DC, USA.

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