The Written Description Requirement as Interpreted in Ariad v. Eli Lilly

George Nathanael is a JD candidate at Osgoode Hall Law School and is taking the Patent Law course.

Earlier this week the U.S. Court of Appeals for the Federal Circuit (CAFC) released an en banc decision on the case of Ariad Pharmaceuticals, Inc. v. Eli Lilly and Company. Ariad sued Eli Lilly for infringement of its patent that identified a transcription factor that activated gene expression for a particular function. However, Eli Lilly was not held to be liable because it was found that Ariad’s patent was invalid for not fulfilling the written description requirement in its specification; namely, it did not discuss examples of actual compounds required in the process and sounded more like a theory.

The CAFC focused on the language of 35 U.S.C. § 112, and determined that it required separate written description and enablement requirements, meaning that specifications that enable a person skilled in the art to make and use the invention do not automatically mean that the description is sufficient, despite the seemingly entwined nature of the two concepts within the wording of the statute.

Perhaps due to applicability of the doctrine of equivalents in the U.S., this decision may have brought greater puzzlement to practitioners south of the border because of the practical insignificance of distinguishing between the written description and the enablement requirement. However, the ruling seems to have the contentious side effect of potentially requiring greater disclosure for validity purposes. Under the doctrine of equivalents, infringing devices or processes do not have to fall within the literal scope of the original patent claim, so that if they essentially do the same thing (under the triple identity test) then they will be caught under infringement laws. It can be argued that in order to know how to essentially do the same thing it should be sufficient to have specifications that contain proper enablement descriptions. So as per the dissent, if a patent fails the enablement test (which would likely be the case with Ariad’s patent as well) it follows that it must also fail the general written description test, such that much of the judgment’s discussion can be rendered meaningless for the purpose of ultimately finding infringement.

The potentially greater disclosure for validity would seem to especially apply to claims that are generic in nature and that apply to a variety of species. With only an enablement requirement, a list of all species that a genus claim applies to is unnecessary; but it seems that now a more stringent written description may require disclosure of all (or some unknown sufficient number of) species covered. This is supported by the court’s statement that “the specification must demonstrate that the applicant has made a generic invention that achieves the claimed result and do so by showing that the applicant has invented species sufficient to support a claim to the functionally-defined genus”. Ultimately, perhaps this case has the effect of pulling away from the doctrine of equivalents (which would likely apply more to functionally-defined genus claims), so that a patent cannot as easily cover that which is outside its scope as interpreted literally. Nonetheless, according to the USPTO’s own guidelines for patentability, written descriptions have the policy objectives of: clearly conveying the subject matter claimed in the invention; putting the public in possession of these claims; disclosing the technological knowledge upon which the patent is based; and promoting progress of the useful arts by making sure an adequate description is provided in exchange for the right to exclude. With this judgment, the court can be said to simply be reaffirming the importance of these objectives.

In the Supreme Court of Canada decision of Free World Trust v. Électro Santé Inc. of 2000, it was decided that the U.S. doctrine of equivalents approach should be rejected on the basis that greater certainty about a patent’s scope would be a more fair approach. Though traditionally, claims have been the primary means of understanding an invention’s scope in infringement cases, the written description requirement of a patent is used as well. CIPO has proposed revisions to Chapter 9 of its Manual of Patent Office Practice (MoPOP), which deals with description. 9.02.05 of the draft of the updated version states that “[t]he person skilled in the art … must be able to practice the full scope of the invention without undue burden or the need to exercise their inventive ingenuity”. It has been argued that these changes could result in even greater disclosure requirements for Canadian patents in the future.

It will be interesting to see the specific effects of both this CAFC decision and the MoPOP revisions with regard to the way patents are prosecuted and interpreted in infringement litigation in their respective countries. The written description’s importance can be explained through a statement from one of the concurring opinions in the judgment: “[t]he practical utility on which commercial value is based is the realm of the patent grant; and in securing this exclusionary right, the patentee is obliged to describe and to enable subject matter commensurate with the scope of the exclusionary right”. Just how strongly both examiners and judges will apply the latest form of the written description requirement is still unknown.