About ANDAs -

Pursuant to the Hatch-Waxman Act, section 505 of the Federal Food, Drug, and Cosmetic Act, codified at 21 U.S.C. § 355, was amended to authorize the filing of ANDAs. 21 U.S.C. § 355; see also Warner-Lambert Co. v. Apotex Corp., 316 F.3d 1348, 1358 (Fed. Cir. 2003). Under 35 U.S.C. § 271(e)(2), it is an act of infringement to submit an ANDA under 21 U.S.C. § 355(j) for a drug claimed in a patent before the patent’s expiration.

So, for Impax to have a chance to sell riluzole, it preemptively sought to down '814.

About ALS -

ALS, commonly referred to as Lou Gehrig’s disease, is a disease of the central nervous system. It involves the progressive degeneration of the nerves that carry impulses to muscles. ALS is characterized by the death of the nerves that control motor function (also called motor neurons). This occurs after the motor neuron cell bodies shrivel and harden, a process called sclerosis. The clinical symptoms of ALS may first appear in the skeletal muscles, referred to as “limb onset” ALS, or in the bulbar muscles of the throat, tongue, and respiratory system, referred to as “bulbar onset” ALS.

The foundation for anticipation laid out by the CAFC is that a reference is enabled if one skilled in the art could create the invention ("without undue experimentation") by reference to the prior art. The prior art need not have disclosed whether the creation works to the claimed purpose to be anticipatory.

An invention is anticipated if it “was . . . described in a printed publication in this . . . country . . . more than one year prior to the date of application for patent in the United States.” 35 U.S.C. § 102(b) (2000). A patent claim is invalid as anticipated if every limitation in a claim is found in a single prior art reference, either explicitly or inherently. See MEHL/Biophile Int’l Corp. v. Milgraum, 192 F.3d 1362, 1365 (Fed. Cir. 1999). “Anticipation is a factual matter, which we review under the clearly erroneous standard.” Glaxo v. Novopharm, 52 F.3d 1043, 1047 (Fed. Cir. 1995).

In order to be anticipating, a prior art reference must be enabling so that the claimed subject matter may be made or used by one skilled in the art. Amgen Inc. v. Hoechst Marion Roussel, Inc., 314 F.3d 1313, 1354 (Fed. Cir. 2003); Helifix, Ltd. v. Blok-Lok, Ltd., 208 F.3d 1339, 1346 (Fed. Cir. 2000); Akzo N.V. v. U.S. Int’l Trade Comm’n, 808 F.2d 1471, 1479 (Fed. Cir. 1986). Prior art is not enabling so as to be anticipating if it does not enable a person of ordinary skill in the art to carry out the invention. See Elan Pharms., Inc. v. Mayo Found., 346 F.3d 1051, 1057 (Fed. Cir. 2003) (remanding the case to the district court for a determination of whether the prior art reference enabled persons of ordinary skill to make the invention without undue experimentation); In re Donohue, 766 F.2d 531, 533 (Fed. Cir. 1985) (“[P]rior art . . . must sufficiently describe the claimed invention to have placed the public in possession of it. Such possession is effected if one of ordinary skill in the art could have combined the publication’s description of the invention with his own knowledge to make the claimed invention.”) (citation omitted).

The enablement requirement for prior art to anticipate under section 102 does not require utility, unlike the enablement requirement for patents under section 112. Rasmusson v. SmithKline Beecham Corp., 413 F.3d 1318, 1325-26 (Fed. Cir. 2005) (“[A] prior art reference need not demonstrate utility in order to serve as an anticipating reference under section 102.” (citing In re Schoenwald, 964 F.2d 1122, 1124 (Fed. Cir. 1992); In re Donohue, 632 F.2d 123, 126 n.6 (C.C.P.A. 1980)); see also In re Samour, 571 F.2d 559, 563-64 (C.C.P.A. 1978); In re Hafner, 410 F.2d 1403, 1405 (C.C.P.A. 1969). In Rasmusson, we held that the Board of Patent Appeals and Interferences (“Board”) erred in determining that a prior art reference was not enabling and thus not anticipatory. 413 F.3d at 1325-26. The patent application in Rasmusson claimed a method of treating prostate cancer by using a chemical called finasteride. Id. at 1320. The prior art reference disclosed a method of treating prostate cancer by using finasteride, but the Board found that the prior art reference was not enabling because it failed to demonstrate that finasteride was “effective” in treating prostate cancer. Id. at 1325-26. We reversed the Board’s determination that the prior art was not enabling and remanded the case for consideration of anticipation, holding that proof of efficacy is not required for a prior art reference to be enabling under section 102. Id.; see also Novo Nordisk Pharms., Inc. v. Bio-Tech. Gen. Corp., 424 F.3d 1347, 1355 (Fed. Cir. 2005) (“The standard for enablement of a prior art reference for purposes of anticipation under section 102 differs from the enablement standard under 35 U.S.C. § 112. . . . While section 112 ‘provides that the specification must enable one skilled in the art to “use” the invention,’ . . . ‘section 102 makes no such requirement as to an anticipatory disclosure,’ . . . . Significantly, we have stated that ‘anticipation does not require actual performance of suggestions in a disclosure. Rather, anticipation only requires that those suggestions be enabled to one of skill in the art.’” (citations omitted)); Bristol-Myers Squibb Co. v. Ben Venue Labs., Inc., 246 F.3d 1368, 1378 (Fed. Cir. 2001) (holding that prior art that suggested a drug was ineffective nevertheless anticipated a patent on that drug); Celeritas Techs. v. Rockwell Int’l Corp., 150 F.3d 1354, 1361 (Fed. Cir. 1998) (“A reference is no less anticipatory if, after disclosing the invention, the reference then disparages it. Thus, the question whether a reference ‘teaches away’ from the invention is inapplicable to an anticipation analysis.”).

As to the specific prior art argument -

Impax argued anticipation by 5,236,940 and French Application No. 2,640,624, from which '940 claims priority. '940 had been identified by the examiner as pertinent, but not the basis of examiner rejection.

'624 identified a class of compounds in which riluzole belongs, but did not specifically identify riluzole in the application.

Here, with the large number of compounds included in formula I and no specific identification of riluzole by the ’624 application, the ’624 application does not disclose riluzole, and therefore, cannot enable treatment of ALS with riluzole.

So, the appeals court agreed with the district court "that the ’624 application does not anticipate."

The CAFC remanded for the district court to determine "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." The prior art references does not need to address the effectiveness of treatment. Thus, with regard to drug treatment, the prior art only has to enable creation of the drug for treatment, and need not go so far as to indicate that the treatment would be effective.

On appeal, Impax argues that the ’940 patent enables treating ALS with riluzole because it provides sufficient guidance to allow one of ordinary skill in the art to determine riluzole’s actual effectiveness against ALS without undue experimentation, as the ’940 patent indicates that the compounds of formula I are active against ALS and specifies the dosage ranges to be given. Impax also argues that the ’624 application anticipates the ’814 patent, but acknowledges that the ’624 application does not exclude riluzole from the compounds included in formula I.

Aventis responds that the ’940 patent—which was considered during prosecution but was not viewed by the examiner as supporting a rejection of the pending claims—does not enable a method of using riluzole to treat ALS, as the ’940 patent discloses hundreds of possible compounds, does not meaningfully discuss riluzole or identify it as a medication, indicates that the compounds of formula I may be useful in treating “a laundry list of diseases,” and offers only “speculation” that the formula I compounds might treat ALS. Aventis further argues that there was no evidence that a person of skill in the art would find the ’940 patent “to indicate efficacy against ALS,” that the district court correctly found that there was uncertainty as to whether riluzole would work to treat ALS, and that the gaps in the ’940 patent cannot be filled by extrinsic knowledge because no such extrinsic knowledge existed. Aventis contends that Impax’s expert, Dr. Jeffery Rothstein, was unable to identify any specific teaching in the ’940 patent that would have led one to riluzole, while its expert, Dr. Benjamin Brooks, testified that one skilled in the art would not have had a reasonable expectation of success in treating ALS based on the disclosure of the ’940 patent. Aventis posits that the decision regarding the ’940 patent would be applicable to the ’624 application.

[T]he district court found that the ’940 patent did not anticipate the ’814 patent because the disclosure of the ’940 patent was not enabling at least in part because there was no evidence that it would be "effective." Validity and Enforceability Order, 333 F. Supp. 2d at 272. However, as we recognized in Rasmusson, proof of efficacy is not required for a prior art reference to be enabling for purposes of anticipation. 413 F.3d 1326. That is, a section 102 prior art reference does not have to be “effective” to be enabling and thus anticipating. Id. Under Rasmusson, the effectiveness of the prior art is not relevant. Id. Rather, 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. As seen above, however, the district court focused only on the former question. Thus, we remand to allow the district court to make the proper factual determinations and then reach its own legal conclusion as to whether the ’940 patent is enabled.

What the district court must determine on remand is whether the disclosure of formula I in the ’940 patent enables a person of ordinary skill in the art to carry out the invention claimed in claims 1-5 of the ’814 patent. See Elan Pharms., 346 F.3d at 1057. Specifically, the district court must determine whether the ’940 patent enables a person of ordinary skill in the art to treat ALS with riluzole. Effectiveness in treating ALS does not have to be established. See Rasmusson, 413 F.3d at 1325-26. If the district court determines that what is disclosed in formula I of the ’940 patent is enabling in that a person of ordinary skill in the art can carry out the invention, then it will be for the district court to determine whether that disclosure anticipates claims 1-5 of the ’814 patent.

In dissent, Judge Rader enumerates the evidence that '940 didn't anticipate -

While the trial court referred to effectiveness, its findings go beyond that narrow ruling and suffice to uphold its judgment. For example, the district court noted first that formula I encompasses a particularly large number of compounds. Impax Labs., Inc. v. Aventis Pharms., Inc., 333 F. Supp. 2d 265, 271-72 (D. Del. 2004). In addition, the district court examined the specification of the ‘940 patent and determined that riluzole was not meaningfully discussed in the treatment of medical conditions associated with the effects of glutamate. Id. at 272. Moreover, the court determined that the language of the ‘940 patent itself created “substantial uncertainty” regarding use of glutamate inhibiting compounds in the treatment of ALS. Id. The court determined that the language in the patent discussing conditions implicating glutamate to be speculative, at best. Id. Thus, I read the district court to have found that the ‘940 disclosure did not put one of skill in the art in possession of the invention at all. Elan Pharms., Inc. v. Mayo Found., 346 F.3d 1051, 1057 (Fed. Cir. 2003). When it found that the disclosure leaves “substantial uncertainty,” the trial court sufficiently supported its holding. Id. The ‘940 disclosure does not make it a potential treatment in any way.

Further, the majority opinion provides even more evidence that the ‘940 patent is not an enabling reference for the purposes of anticipating the ‘814 patent. For example, the opinion notes that the ‘940 patent was considered by the examiner during prosecution and not considered a prior art reference to support a rejection of the claims. Majority Opinion, 23. In addition, the opinion points out that Impax’s own expert “was unable to identify any specific teaching in the ‘940 patent that would have led one to riluzole.” Id. Further, Aventis’ expert found that the disclosure of the ‘940 patent would not have given a person a reasonable expectation of success in treating ALS. Id. at 24. Once again, the record – even beyond the parts cited by the trial judge – show no anticipation.

Anticipation does not require proof of “utility,” or (in other words) “actual performance of suggestions in a disclosure,” Bristol-Myers Squibb Co. v. Ben Venue Labs., 246 F.3d 1368, 1378 (Fed. Cir. 2001), but in this case, the district court has found that the disclosure does not make even a suggestion of disclosure to one of skill in the art. Beyond the efficacy question, the ‘940 patent does not even disclose the necessary suggestion to enable one of ordinary skill in the art to look to riluzole for the treatment of ALS in the first place.