United States: Federal Circuit OK's Use Of Post-Priority-Date Evidence

Last Updated: October 16 2017
Article by Michael J. Abernathy and Jennifer Dienes

The ruling found that the use of such evidence was proper for written description and enablement.

The US Court of Appeals for the Federal Circuit issued its opinion on October 5 in Amgen Inc. v. Sanofi, Case No. 2017-1480, in which it was asked to address several evidentiary issues on appeal, including whether the district court improperly excluded post-priority-date evidence Sanofi had offered to show that the asserted patents lacked written description and enablement. The Federal Circuit concluded that such evidence was proper, provided that it was not used to shed light on the state of the art on the priority date, but rather to show proof of lack of written description or enablement. As a result, the court reversed the district court's rulings on written description and enablement and remanded the case for a new trial.

Amgen alleged that Sanofi's and Regeneron's (collectively Sanofi) Praluent® infringed the claims of two patents. The asserted claims are directed to a genus of antibodies that binds to specific amino acid residues on the protein PCSK9 and block PCSK9 from binding to LDL receptors. At the district court, Sanofi and Regeneron stipulated to infringement but challenged the validity of Amgen's asserted patents based on written description, enablement, and obviousness grounds. After a jury trial, the district court entered judgment that the asserted patents were not invalid and granted a permanent injunction enjoining sales of Praluent®.

On appeal, Sanofi argued that the district court improperly (1) excluded evidence regarding written description and enablement; (2) instructed the jury on written description; (3) denied its judgment as a matter of law (JMOL) of no written description and no enablement; (4) granted Amgen's JMOL of non-obviousness; and (5) issued a permanent injunction.

I. Exclusion of Evidence Regarding Written Description and Enablement

The district court excluded Sanofi's evidence about antibodies, including Praluent®, that were developed after the asserted patents' priority date of January 9, 2008. It reasoned that the evidence was not relevant to determine whether there was sufficient disclosure of the claimed invention because it did not "illuminate" the state of the art at the time a filing.

The Federal Circuit disagreed, noting that for genus claims to show possession of the claimed invention as of the filing date, "a patentee must disclose a representative number of species falling within the scope of the genus or structural features common to the members of the genus, so that one of skill in the art can visualize or recognize the members of the genus." (internal quotations omitted). The parties disputed whether a court may rely on "post-priority-date evidence to determine if a patent discloses a representative number of species." (internal quotations omitted).

The Federal Circuit acknowledged that post-priority-date evidence regarding the state of the art is not relevant to written description, but observed that "[e]vidence showing that a claimed genus does not disclose a representative number of species may include evidence of species that fall within the claimed genus but are not disclosed by the patent, and evidence of such species is likely to post-date the priority date." In fact, the court noted that if such evidence predated the priority date, it could anticipate the claimed genus.

Sanofi offered Praluent® and other post-priority-date antibodies to show that the "claimed genus fails to disclose a representative number of species." The Federal Circuit held that the use of such evidence is proper and that the district court erroneously excluded Sanofi's post-priority-date evidence. Thus, it reversed the district court and remanded the case for a new trial on written description.

The Federal Circuit applied the same analysis regarding enablement and held that post-priority-date evidence showing undue experimentation was also relevant and proper. Sanofi sought to introduce post-priority-date evidence that Amgen "engaged in lengthy and potentially undue experimentation to enable the full scope of the claims." The Federal Circuit found that this evidence could have been relevant to determining enablement. Thus, it reversed the district court and remanded the case for a new trial on enablement.

II. Jury Instruction On Written Description

Sanofi also alleged that the district court improperly instructed the jury on written description. The Federal Circuit found that the district court correctly instructed the jury that to satisfy the written description requirement, "a patentee may disclose either a representative number of species falling within the scope of the genus or disclose structural features common to the members of the genus so that one of skill in the art can visualize or recognize the members of the genus." However, the district court also instructed the jury that "the correlation between structure and function" could be satisfied by the disclosure of a "newly characterized antigen." Sanofi argued that the instruction was erroneous because an antigen is not sufficient for a claim to an antibody to satisfy the written description requirement.

The Federal Circuit found that the "essential problem" with the jury instruction was that "it effectively permitted the jury to dispense with the required finding of a written description of the invention." (internal quotations omitted). The court also noted that the instruction did not require any particular antibody to be easily made, but only required that the production of antibodies against a newly characterized antigen be conventional or routine. The Federal Circuit found that the newly characterized antigen test flouted basic legal principles and improperly would allow patentees "to claim antibodies by describing something that is not the invention, i.e., the antigen." Further, the court stated it could not take judicial notice of the premise behind the "newly characterized antigen" test in the instruction because that premise was not generally known or accurately and readily ascertainable. The Federal Circuit thus held the jury instruction was improper and directed the district court to amend it on remand.

III. JMOL of No Written Description and No Enablement

With respect to Sanofi's JMOL of no written description and no enablement, the Federal Circuit held that because not all of the evidence was before the jury, it could not conclude that Sanofi was entitled to JMOL. In particular, the court noted that the evidence could show "that practicing the invention did not require undue experimentation or that disclosed species are representative of the claimed genus."

IV. JMOL of Non-Obviousness

The Federal Circuit upheld the district court's grant of Amgen's JMOL of non-obviousness because it correctly excluded the proffered prior art references as improper prior art. Sanofi's prior art references—two published PCT applications—did not predate the priority date of the asserted patents. Additionally, when attempting to rely on the references under § 102(e), Sanofi failed to show that the provisional applications the references claimed priority to provided written description support for the claims of the PCT applications. As a result, the district court's grant of JMOL of non-obviousness was proper.

V. Permanent Injunction

Finally, because the district court's written description and enablement decisions were vacated and the case remanded for a new trial, it also vacated the permanent injunction. In doing so, the Federal Circuit noted that the district court's analysis of the public interest was erroneous and that it should not have entered an injunction after finding that it would disserve the public interest. In particular, Amgen was required to show that the public interest would not be disserved by the grant of a permanent injunction. Additionally, the Federal Circuit held that the district court erred in its analysis of the public interest factor by focusing on the injunction's effect of taking a helpful drug off the market. The elimination of a choice of drugs, as the Federal Circuit found, is not sufficient by itself to disserve the public interest and cannot be the sole reason to deny an injunction.

This article is provided as a general informational service and it should not be construed as imparting legal advice on any specific matter.

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