In an en banc opinion, the Federal Circuit held in Ariad Pharms v. Eli Lilly & Co., 2008-1248 (March 22, 2010) that 35 U.S.C. § 112 contains both a written description (“WD”) requirement and an enablement requirement and that these requirements are separate and distinct. The holding of such separate and distinct requirements is not necessarily new – a separate written description requirement has existed at least since the court decided Regents of the University of California v. Eli Lilly & Co. in 19971 - the court drew a firm line and decisively articulated that confusion regarding the separateness of the requirements should be dismissed.

The Federal Circuit decided to take up the question after a panel of the court overruled the lower court and held that Ariad’s asserted claims were invalid for lack of written description. Ariad petitioned the court for an en banc rehearing asserting that 35 U.S.C. § 112 did not contain a separate written description requirement.

In a 72 page opinion, including concurrences and dissents, the court reaffirmed the separate written description and enablement requirements based on the language of the statute, Supreme Court precedent, and stare decisis. The court stated that, for the written description requirement, “the test for sufficiency is whether the inventor had possession of the claimed subject matter as of the filing date.” Acknowledging that the term “possession” has not been particularly instructive, the court stated that “. . . the hallmark of written description is disclosure. Thus, ‘possession as shown in the disclosure’ is a more complete formulation.” The court further stated that “. . . the test requires an objective inquiry into the four corners of the specification from the perspective of a person of ordinary skill in the art. Based on that inquiry, the specification must describe an invention understandable to that skilled artisan and show that the inventor actually invented the invention claimed.” It is worth noting that the court further held that the written description requirement applies in the same manner to amended and original claims, and is not limited to priority cases.

A few “broad principles” applicable in cases leading up to this decision were articulated by the court:

  • the WD requirement does not demand either examples or an actual reduction to practice;
  • a constructive reduction to practice that in a definite way identifies the claimed invention may be sufficient;
  • actual “possession” or reduction to practice outside of the specification is not sufficient – the specification itself must demonstrate possession; and
  • a description that merely renders the invention obvious does not satisfy the requirement.

The court also specifically addressed the purpose and role of the WD requirement to shed light on its applicability, saying that the WD requirement:

  • plays a vital role in curtailing claims that do not require undue experimentation to make and use, and thus satisfy enablement, but that have not been invented, and thus cannot be described;”
  • “ensures that when a patent claims a genus by its function or result, the specification recites sufficient materials to accomplish that function – a problem that is particularly acute in the biological arts;”
  • “ensure[s] that the scope of the right to exclude, as set forth in the claims, does not overreach the scope of the inventor’s contribution to the field of art as described in the patent specification.” (citations omitted).

The court decisively rejected Ariad’s argument that the WD requirement unfairly disadvantages universities doing basic research that would not be able to meet the WD requirement. The court stated that the patent process does not exist to reward those doing basic research, but rather those “who actually perform the difficult work of ‘invention’ – that is, conceive of the complete and final invention with all its claimed limitations – and disclose the fruits of that effort to the public.”

Practice Comments
The substance of the opinion leaves the law of written description substantially unchanged. However, the publicity of the case and the opinion being en banc may result in an increase in the use of WD as a basis for claim rejections or invalidity attacks. Particularly, the opinion reminds practitioners that an enabling disclosure alone may not always be sufficient to satisfy the requirements of § 112 and that insufficient written description can exist even if an enabling disclosure has been provided.

In the course of patent prosecution, it is all too often the case that the claim language strays from what was originally described in the specification, particularly where the references cited by the patent office are close to the claimed invention. In these situations, the claim language may be enabled by the specification, in that the overall concepts embodied in the claim are similar enough to the disclosure to enable one of skill in the art to make and use the invention. Whether sufficient written description has been provided may be less clear.

Where the claim language cannot be found in the specification, the question for written description is whether the disclosure reasonably convey to those skilled in the art that the inventor had possession of the claimed subject matter. Where the specification and prosecution history suggest that the inventor had not contemplated this version of the invention until faced with the cited references, an invalidity argument based on lack of written description may be apropos. This may be particularly true where a single embodiment is described and no alternatives are included in the specification, or where broad terms are used to describe a single embodiment, but no examples are provided for what types of elements are represented by those broad terms. In these cases, where claims focus on elements not in the single embodiment or on elements that are not disclosed but are similar to those in the single embodiment and arguably within the broad terms, the written description requirement may not be met. This can lead to rejections during prosecution and/or invalidity attacks during litigation.

It remains true, however, as was highlighted in the case and several of the Amicus briefs, that invalidity findings based on insufficient written description alone are rare. While the case history suggests that written description problems can arise in mechanical arts cases, the more recent cases that invalidate claims for lack of written description have occurred in the chemical or biological arts where a species is disclosed but a genus is claimed. Additionally, while the court has not limited the rule to questions of priority, a lack of written description is most often found in the priority context.

In light of Ariad, the written description requirement may be raised more frequently in several contexts, including opinions, preparation of patent applications, and patent prosecution.

In the case of opinions, patent practitioners may be more apt to include discussions relating to invalidity of a patent based on a failure to provide sufficient written description under § 112. This may be particularly true where a claim’s language cannot be specifically found in the specification and/or other factors suggest that the language may be inconsistent with what the applicant originally had in mind. One tip for recognizing a potential written description problem is to pay particular attention when a claim amendment broadens all or part of a claim.

In the context of patent applications, Ariad reminds practitioners and clients that it is important to flesh out examples and fully define terms used in patent applications. Accordingly, as inventors and/or applicants, it remains important to take questions seriously from your patent attorney relating to alternatives, ranges, and modifications. A reasonable amount of thought should be given to how an invention as a whole could be modified, as well as to how the individual elements of the invention could be modified. Conveying those alternative examples to your patent attorney for inclusion in the application remains sound patent prosecution strategy.

In the patent prosecution context, using claim terminology and language that is consistent with language used in the specification is good practice, particularly when amending claims. Generally, originally filed claims are considered original disclosure in a patent application. If during prosecution it is discovered that the language of the originally filed claims was not contained in the detailed description at the time of filing, it is good practice to amend the specification to include the exact language of the originally filed claims. This can reduce the ability to attack the claims based on written description. However, it remains true that if the claim language is overly broad and not supported by examples, a written description rejection remains proper even in light of the specification amendment.

The court in Ariad did not change applicable law regarding the written description requirement. It did, highlight, the importance of considering issues related to written description throughout drafting and prosecution patent applications. It also gave teeth to invalidity attacks where such consideration is not adequately given.

1 In fact, earlier cases, such as In re Barker and Pehl decided by the Court of Customs and Patent Appeals in 1977, recognized the separate written description requirement also.