Federal Circuit affirms finding of no anticipation or obviousness, no mention of KSR to be foundSeptember 6, 2007

The Federal Circuit yesterday affirmed a decision by the District Court for the District of Delaware upholding the validity of Reissue Patent 34,712 ("the '712 patent") and the injunction preventing infringement of the '712 patent. Specifically, the court affirmed the district court's decision that the prior art reference relied upon for the defendants' anticipation argument was not enabling, and thus could not anticipate the claims. Also, the finding of no obviousness was affirmed, because the district court correctly assessed the Graham factors, and in light of those factual findings, the legal conclusion of obviousness was correct.

The court also affirmed the finding that there had not been an impermissible broadening reissue filed more than two years after the patent was granted. Finally, the court limited the injunction to only the specific products that were the subject of the Abbreviated New Drug Application (ANDA) that led to the lawsuit, but affirmed the inclusion of both defendants as parties to the injunction, even though one would only be liable for inducing infringement.

The reissue patent involved is directed toward a substantially pure (+)-enantiomer of citalopram and the nontoxic acid additional salts thereof (commonly referred to as "escitalopram," generic name for the antidepressant Lexapro®). An enantiomer is a type of stereoisomer (chemical compound with the structure but a different spatial arrangement) that is a nonsuperimposable mirror image of another compound.

The district court found the '712 patent valid and stated that it was not anticipated by a reference disclosing the stereoselectivity of serotonin reuptake (means used to increased serotonin in the brain to treat depression) as it did not disclose "substantially pure" escitalopram. Additionally, the court concluded that it would have required undue experimentation for one of ordinary skill in the art to separate the enantiomers of citalopram at the time of the invention. The court also found that there was no reasonable expectation of success in isolating pure (+)-enantiomer based on the knowledge of those skilled in the art at the time of the invention, and as a result the patent was not obvious. The court further held that the claims were not broadened during reissue when a compound in the claimed method was changed from "a (+)-diol intermediate" to "a (-)-diol intermediate" because the change amounted to correction of a typographical error, and as such the claim scope was unchanged. After entering judgment, the court enjoined Ivax and Cipla from engaging in any act that would infringe the '712 patent, including production of the compounds referred to in their ANDA.

The defendants, Ivax and Cipla, appealed to the Federal Circuit.

On appeal, the Federal Circuit first affirmed the district court's conclusion that the '712 patent was not anticipated. The court referred to the expert testimony from trial, noting that the disputed reference was a pharmacology, rather than a chemical paper, and did not tell how to obtain the (+)-enantiomer of citalopram. In addition, there was substantial evidence that many others attempted to isolate the (+)-enantiomer of citalopram but were unsuccessful in doing so. Essentially, the defendants argued that the evidence they presented should have led the district court to conclude the patent was anticipated, but the Federal Circuit held that there was substantial evidence supporting the district court's factual finding of no anticipation. Therefore, the finding of no anticipation based on the non-enabling reference was affirmed.

The court then affirmed the finding that the '712 patent was not obvious. The defendants argued that in light of the known enantiomers of citalopram, the general expectation that one of the enantiomers would be superior to the other, and the various descriptions of techniques available to separate enantiomers in the art, producing the claimed compound would be obvious. Once again, the Federal Circuit faulted the defendants for simply emphasizing evidence favorable to its case while not addressing the evidence favorable to the plaintiff (and therefore supporting the district court's conclusion). As stated by the court:

The district court applied the Graham factors to conduct a thorough analysis of the evidence, and we find no clear error on facts and no error of law. See Graham v. John Deere Co., 383 U.S. 1 (1966). These findings fully support the conclusion that the claimed subject matter would not have been obvious to one of ordinary skill in the art.

Ivax also challenged the validity of the reissue patent based on a broadening of the original claim 11 after more than two years had elapsed. However, the Federal Circuit again agreed with the district court's determination that the change in claim language was a mere correction to a typographical error that was apparent to one of ordinary skill in the art reviewing the patent and therefore did not broaden the scope of the patent. Notably absent was any mention of KSR in the court's analysis; the court appears to have simply reverted to applying the Graham factors to the obviousness analysis here.

Finally, the Federal Circuit reviewed the scope of the injunction. The court disagreed with the scope of the district court's injunction. Quoting International Rectifier, 383 F.3d 1312, 1316 (Fed. Cir. 2004), the court stated:

[T]he only acts [an] injunction may prohibit are infringement of the patent by the adjudicated [products] and infringement by [products] not more than colorably different from the adjudicated [products]. The court modified the injunction accordingly to prohibit manufacture, use, offer to sell, or sale of the approved drug (escitalopram oxalate), and not any products covered by the '712 patent.

The court did affirm the inclusion of Cipla within the injunction. Cipla was assisting Ivax with the FDA approval for an ANDA. Based on this Cipla "actively induced the acts of Ivax that will constitute direct infringement upon approval of the ANDA, and it was thus not inappropriate for the district court to include Cipla within the scope of the injunction." Judge Schall dissented from just this aspect of the court's decision, asserting that the plain language of § 271(e)(2) limits the act of infringement to the filing of the ANDA application, and thus Cipla could not induce infringement based on actions relating to the ANDA. The dissent also claimed the legislative history of § 271(e)(2) indicated it was meant to explicitly exempt acts relating to the development of the ANDA, such as Cipla's actions here.

Notably absent from the discussion of the injunction was any citation to the Supreme Court's eBay case, or the equitable considerations recited in that case. It seems logical to conclude that Ivax and Cipla simply chose to attack the injunction on other grounds, though, so don't bet on courts moving away from the eBay standard.

To read the full decision in Forest Labs., Inc. v. Ivax Pharms., Inc., click here.

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