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05.17.2010 | Legal Advisory

On March 22, 2010, the Federal Circuit handed down an en banc decision holding that the “written description” requirement for patent applications is distinct from the enablement requirement. The decision all but assures that the U.S. Patent and Trademark Office (USPTO) will continue its policy of heightened scrutiny for biotechnology patent applications.

The decision dealt with the first paragraph of section 112 of the patent statute, which provides:

The specification shall contain a written description of the invention, and of the manner and process of making and using it, in such full, clear, concise, and exact terms as to enable any person skilled in the art to which it pertains, or with which it is most nearly connected, to make and use the same, and shall set forth the best mode contemplated by the inventor of carrying out his invention. [35 U.S.C. 112] (Emphasis added)

In the Ariad Pharmaceuticals, Inc. v. Eli Lilly and Co.¹ case, the Court of Appeals for the Federal Circuit upheld an earlier panel decision, reversing a trial verdict in favor of Ariad and its licensors, MIT and Harvard University against Eli Lilly, the manufacturer of Evista and Xigris, drugs for treatment of osteoporosis and sepsis, respectively. The Federal Circuit’s en banc decision found the asserted patent claims were invalid due to a lack of written description.

The Federal Circuit chose to hear this case before its eleven judges to settle whether the “written description” requirement is a requirement under section 112 separate from the enablement requirement, and, if so, to clarify the scope and purpose of the written description requirement.

In a nearly unanimous (9-2) decision, the court agreed with Eli Lilly that section 112 provides a written description requirement distinct from the requirement of providing an enabling description. One of the reasons for this requirement was to ensure that the scope of the patentee’s right to exclude “does not overreach the scope of the inventor’s contribution to the art.” In essence, inventors must demonstrate that they were in “possession” of the invention they seek to claim.

In the Ariad case, the patent at issue involved a discovery by some of America’s most prominent biotech researchers, including Nobel Laureates David Baltimore and Phil Sharp, of a transcription factor, NF-kB, which affects cytokine production. The inventors also realized that reducing NF-kB activity could treat or mediate certain immune disorders associated with overproduction of cytokines. The inventors broadly claimed methods of modulating the NF-kB pathway. For example, claim 95 of U.S. Patent 6,410,516, (rewritten in independent form) reads as follows:

A method for reducing, in eukaryotic cells, the level of expression of genes which are activated by extracellular influences which induce NF-kB mediated intracellular signaling, the method comprising reducing NF-kB activity in the cells such that expression of said gene is reduced, carried out on human cells. (Emphasis added)

It is noteworthy that claim 95 does not specify particular compounds, either by chemical formula or any other characterizing feature, to reduce NF-kB activity. This type of invention is sometimes referred to as a “pathway” patent, in that the inventors have discovered a step in a physiological pathway and attempt to claim all agents that can modify the pathway.

The court found that the patent’s original 1989 disclosure of the invention disclosed three general categories of agents that could interfere with NF-kB activity but no therapeutic compositions. The court dismissed a prophetic example in the patent as an insufficient written description, characterizing it as “not so much an ‘example’ as it is a mere mention of a desired outcome.”

Critics of the Ariad decision argue that finding a separate written description test in section 112 requires a strained grammatical reading of the statute and that such a reading has no support in the legislative history of the patent act. Moreover, they note that section 112 clearly requires that patent applicants must provide an “enabling disclosure” of their inventions and that this is a clearer test – and one that makes the written description requirement redundant.

The Ariad decision, itself, does not provide much useful guidance on how the separate “written description” test should be applied. The majority opinion states that the applicant must “possess” the claim invention but fails to explain how this test should be applied in practice to “genus” claims. The opinion suggests that a written description of a genus requires either (1) a representative number of species falling within the genus, or (2) description of “structural features common to members of the genus so that one skilled in the art can ‘visualize or recognize’ members of the genus.” However, the opinion is not particularly enlightening on the status of species that fall within a claimed genus but are not specifically disclosed by the patentee. Moreover, the “visualize or recognize” test appears to bring the factual inquiry back to an enablement test.

The Federal Circuit’s opinion noted that “the level of detail required to satisfy the written description requirement varies depending on the nature and scope of the claims and on the complexity and predictability of the relevant technology.” Thus, for predictable arts (e.g., mechanical inventions) the written description requirement may have little impact but inventions in the fields of biotechnology and pharmacology are likely to be more strictly scrutinized for their level of detail in the written description.

The big winner in the Ariad case appears to be the USPTO because the opinion gives tacit approval to the government’s current strict approach to examination of biotechnology inventions. Since 2001, the USPTO has had guidelines in place for examiners that assume that the written description test is indeed a separate test and that it should be applied to all inventions in unpredictable arts. The most recent iterations of the USPTO position can be found in “Written Description Training Materials, Rev. 1, March 25, 2008² and in the Manual of Patent Examining Procedure §2163 “Guidelines for Written Description Rejections.”³

The USPTO guidance gives numerous examples of what will and will not satisfy the written description requirement. In one instance, the training materials propose the following hypothetical claim:

An isolated nucleic acid that encodes a protein that binds to the NDG receptor and stimulates tyrosine kinase activity.

The example also posits that the applicant has only disclosed a single protein agonist to the NDG receptor. According to the training materials, this claim must be rejected for lacking adequate written description because the application does not identify what domain of the protein binds to the receptor and reads upon numerous unidentified receptor agonists having such a binding domain, as well as nucleic acids encoding agonists with non-canonical binding domains. The training materials conclude:

Given the high degree of variability that may be found in receptor agonists, and that the number of species required to form a representative number varies proportionally with the degree of variability within the claimed genus, those of ordinary skill in the art would not consider the applicant to have been in possession of the entire breadth of the claimed genus of nucleic acids based on the single species disclosed.

Critics of the USPTO training materials have suggested that the guidance encourages examiners to question every aspect of the disclosure – including many aspects where one skilled in the art would recognize that a single example is indeed sufficient to possess many obvious alternatives. Practically speaking, they complain that biotechnology inventions are scrutinized for their concrete examples – and examiners seek to limit the claims to only cover the specific disclosed embodiments.

In the wake of the Ariad decision, it appears that applicants should expect this heightened scrutiny and challenges from examiners at every turn. Whenever possible, multiple examples, multiple species and detailed characterization of the features of the invention should be presented. In the case of the isolated nucleic acid claim discussed above, it appears clear that the applicant would have fared better if the protein domain that bound to the NDG receptor was better characterized or numerous protein agonists were described.

The written description requirement may also require disclosures of numerous ranges bracketing the specific examples to provide fallback positions. For example, if the DNA sequence encoding a protein agonist is all that is known, claiming that sequence and other sequences that have 70% identity, or 80% or 90% or 95% or 96%, etc., may be helpful.

The problem presented in the Ariad case, however, will be difficult for applicants to overcome in that the discovery of a new pathway may indeed be insufficient to claim methods of treatment by modulating the pathway. Unless a representative number of working examples of compounds that can actually perform the method are presented, the “written description” requirement may preclude patentability.

¹560 F.3d 1366 (Fed. Cir. 2009)
²http://www.uspto.gov/web/menu/written.pdf
³http://www.uspto.gov/web/offices/pac/mpep/documents/2100_2163.htm

This advisory was prepared by Nutter's Intellectual Property practice. For more information, please contact your Nutter attorney at 617-439-2000.

This update is for information purposes only and should not be construed as legal advice on any specific facts or circumstances. Under the rules of the Supreme Judicial Court of Massachusetts, this material may be considered advertising.