Broader Implications of Ariad v. Lilly: The Federal Circuit Affirms the Existence of Separate Written Description Requirements

22 March 2010 Publication
Authors: Courtenay C. Brinckerhoff Jeanne M. Gills Stephen B. Maebius

Legal News Alert: Intellectual Property

On Monday, March 22, 2010, the Court of Appeals for the Federal Circuit affirmed an interpretation of the “written description” requirement that has broad implications for patent applicants and patentees in almost every technology. The 9-2 en banc opinion in Ariad Pharmaceuticals, Inc. v. Eli Lilly & Co., No. 2008-1248, affirmed a line of precedent holding that a patent’s specification must contain a written description of the claimed invention that is separate from the requirement that the specification must enable a person of ordinary skill in the art to make and use the claimed invention. Strict application of this requirement tends to narrow the scope of valid claims that can be based on the disclosure of a particular patent’s specification.

The Court’s order granting rehearing en banc asked the parties to address two questions:

  1. Whether 35 U.S.C. § 112, ¶ 1, contains a written description requirement separate from an “enablement requirement?”
  2. If a separate written description requirement is set forth in the statute, what is the scope and purpose of that requirement?

Slip op. at 5. The case attracted a great deal of interest, and 25 amicus briefs were filed on behalf of such diverse parties as medical device manufacturers, drug companies, semiconductor manufacturers, and law professors.

Interest in the case was high because of a perception that the Court’s opinion could have implications for a patent applicant’s ability to obtain valid claims with a broad generic scope based upon a narrow disclosure. In this case, both the District Court and the Federal Circuit’s prior decision had invalidated the patentee’s generic claims to all substances that achieve a desired result where the specification had not disclosed any substances that actually achieved the result.

The Holding

The en banc court held that a patent’s specification must satisfy two written description requirements. First, the specification must have a written description of the invention. Second, the specification must have a written description that enables a person of ordinary skill in the art to make and use the invention. The latter requirement—the enablement requirement—was not at issue in this case. Rather, in its opinion, the Court addressed whether the first requirement was mandated by statute and, if so, how parties could judge whether the specification satisfied the requirement.

The Court found that the existence of separate written description requirement was supported by (1) the statutory language, Slip op. at 7-12; (2) Supreme Court precedent interpreting previous versions of the patent statute, Slip op. at 12-15; (3) the Federal Circuit’s own precedent, Slip op. at 16-18; and (4) stare decisis, Slip op. at 15-16. As the Court explained, the requirement that a patentee provide a written description of the invention is part of the quid pro quo underlying the patent system. Slip op. at 12.

The Court further explained that compliance with the written description requirement is measured by determining whether a person of ordinary skill in the art would understand from the contents of the patent’s disclosure that the inventor was “in possession” of the claimed subject matter, i.e., that the inventor actually invented the invention claimed. The Court’s discussion makes clear that this test is to be applied in a way that may effectively require disclosure of the claimed invention in ipsis verbis along with working examples. For example, the Court states that “the specification itself must demonstrate possession. And while the description requirement does not demand any particular form of disclosure, or that the specification recite the claimed invention in haec verba, a description that merely renders the invention obvious does not satisfy the requirement.” Slip op. at 25 (citations omitted). Thus, while “a propyl or butyl compound may be made by a process analogous to a disclosed methyl compound, but, in the absence of a statement that the inventor invented propyl and butyl compounds, such compounds have not been described and are not entitled to a patent.” Slip op. at 26. The Court further stated that the written description inquiry is fact specific, and the details of the analysis will vary from case to case “depending on the nature and scope of the claims and on the complexity and predictability of the relevant technology.” The Court, therefore, refused to provide any bright line rules such as how many species must be disclosed to support a claim to a genus.

In addition to the Court’s primary opinion, written by Judge Lourie, there were four additional opinions. Judge Newman joined the majority opinion, but wrote separately to address Ariad’s policy argument that a separate written description requirement would be a disincentive to basic research. Judge Newman emphasized that the Court’s jurisprudence always required “a transition . . . from basic science to its application” to warrant patent protection. Judge Gajarsa emphasized that the Court’s interpretation of the statute was reasonable in view of the ambiguous statutory language. Judges Rader and Linn dissented, disagreeing with the Court’s statutory interpretation and decrying the practical effects of the decision.

Effects of the Court’s Holding

Because the Court affirmed its own precedent, its decision should only reinforce the incentives that already exist for patent applicants to write detailed specifications. As the Court explains, the claims define and circumscribe the invention, while the written description discloses and teaches. Slip op. at 15. For this reason, generic claims typically are supported by a representative number of species falling within the genus or by structural features common to members of the genus so that one of skill in the art can visualize members of the genus. Slip op. at 21.

The Court’s decision makes the applicants’ decision as to when to file critical. Filing too soon in the research process before confirming examples are available risks a finding that the application will lack “representative” examples to meet the possession requirement. Filing too late in the research process creates a risk that the applicant will lose the race to the USPTO against a competitor. Striking the right balance will require careful analysis of how many examples are representative in relation to the scope of the claims.

While compliance with the written description requirement is a question of fact and each patent is unique, it is likely that the Court’s opinion form the basis of challenges to the broadest claims in patents that only have a few working examples.

Implications for Other Technologies

While this case arose in a pharmaceutical context, the Court’s holding has implications for all technical areas. The standard announced by the court may provide a basis for limiting the breadth of claims that can be supported by a patent’s specification. Applying this standard, the Court already has invalidated claims in a wide range of technologies, including the mechanical (Gentry Gallery, Inc. v. Berkline Corp., 134 F.3d 1473 (Fed. Cir. 1998), (invalidating patents on reclining sofas)) and electronic/software arts (LizardTech, Inc. v. Earth Resource Mapping, Inc., 424 F.3d 1336 (Fed. Cir. 2005)).

The Court’s holding, therefore, may provide additional ammunition for defendants in cases where parties are attempting to assert patents granted in the early years of the Internet patent boom. Many of these patents have broad claims supported by relatively thin disclosures. These arguments could be asserted as an affirmative defense in an infringement case.

Prospects for Further Addressing This Issue

Barring Supreme Court review, this should be the final word on this issue. In this case, Supreme Court review—always hard to obtain—seems particularly unlikely. Patent cases taken by the Supreme Court in recent years have tended to be those in which the Supreme Court could rein in what it apparently perceives to be an overly patentee-friendly Federal Circuit holding. Because the Federal Circuit’s holding in this case may be viewed as tightening patentability requirements, the case is unlikely to attract Supreme Court review.

Parties seeking to have broad patent protection available for basic research may seek to have Congress amend the patent statute to overturn this decision. As a practical matter, they are unlikely to succeed in the near future. The patent reform legislation now before Congress is supported by a broad coalition of interest groups, the vast majority of whom would oppose adding this issue at the risk of upsetting the existing compromise consensus that has taken a long time to form. Furthermore, once the current patent reform bill is adopted, Congress is unlikely to revisit patent issues for several years.


The Federal Circuit’s en banc decision generally affirms existing case law and confirms that a patent specification must show that the inventor actually possessed the claimed invention at the time of filing. While not creating new standards or providing specific guidelines, the decision is likely to encourage challenges to the validity of claims that broadly encompass subject matter not expressly discussed in the specification. The Court’s re-emphasis of this principle provides an opportunity for parties using the patent system to reevaluate their current practices.

Legal News Alert is part of our ongoing commitment to providing up-to-the-minute information about pressing concerns or industry issues affecting our clients and colleagues. If you have any questions about this update or would like to discuss this topic further, please contact your Foley attorney or the following:

George C. Best
Silicon Valley Office

Courtenay C. Brinckerhoff
Washington, D.C.

Jeanne M. Gills
Chicago, Illinois

Stephen B. Maebius
Washington, D.C.

Larry L. Shatzer
Washington, D.C.