In a decision handed down today, the Federal Circuit has given Impax Laboratories another chance to prove to a Delaware judge that its ANDA application is not hampered by Aventis Pharmaceuticals's patent. The appellate court agreed that Impax had failed to prove inequitable conduct at trial, but found that one of two pieces of prior art may have enabled Aventis's riluzole compound, a drug used to treat ALS (Lou Gehrig's disease). According to the three-judge panel, the district court, by looking only to the effectiveness of the prior art's alleged teaching, failed to fully analyze the question of enablement.
The district court ceased its enablement analysis once it found that the reference, although disclosing riluzole, was only one of many disclosed compounds. Because it was not meaningfully discussed in the prior art, the district court concluded that it could not enable a person of ordinary skill in the art to recognize the value of using riluzole for treating ALS.
Rejecting that finding, the Federal Circuit held that "the effectiveness of the prior art is not relevant." Instead, the Court explained that:
The proper issue is whether the '940 patent is enabling in the sense that it describes the claimed invention sufficiently to enable a person of ordinary skill in the art to carry out the invention . . . . [T]he district court focused only on the former question [of efficacy].
<%media(20061120-Impax.pdf|Impax Labs. Inc. v. Aventis Pharma. Inc., 05-1313 (Fed. Cir. Nov. 20, 2006). )%> The Court therefore vacated the non-enablement finding and remanded for further inquiry into whether the prior art enables one of ordinary skill "to treat ALS with riluzole."