Generally speaking, an inventor may receive a patent for an invention under U.S. patent law if it is directed to eligible subject matter and novel and is nonobvious over the prior art.  In addition, a patent application must contain an adequate “descriptiveness” of the invention under the first paragraph of 35 U.S.C. § 112 for issuance of a patent in accordance with the quid pro quo policy objective of the patent system of encouraging disclosure of inventions in return for protection. 35 U.S.C. § 112, ¶ 1 reads as follows:

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.

Over the years, commentators and courts have debated whether this statutory provision includes a separate “written description” requirement in addition to the “enablement” and “best mode” requirements.  The enablement requirement refers to the language requiring that the specification of a patent application provide sufficient disclosure 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 [invention] . . .”  However, it has been considered less clear whether the language of 35 U.S.C. § 112, ¶ 1 further recites that the specification contain “a written description of the invention” as a requirement that is separate and distinct from the aforementioned enablement requirement, and if so, what is the scope and purpose of such a “written description” requirement?  These are the exact issues addressed by the recent Federal Circuit decision in Ariad Pharmaceuticals Inc. v. Eli Lilly & Co., 598 F.3d 1336, 94 U.S.P.Q.2d 1161 (Fed. Cir. 2010), discussed infra.

As far back as 1967, the predecessor court of the Federal Circuit recognized the existence of a written description requirement separate from enablement.  In In re Ruschig, 379 F.2d 990, 154 U.S.P.Q. 118 (CCPA 1967), the court held that amendment to claim a specific compound was not supported by the original application providing a broader disclosure because there were insufficient “blaze marks” in the application to lead to the specific compound claimed.  The court further stated “the question is not whether [a person] would be so enabled but whether the specification discloses the compound to him, specifically, as something appellants actually invented.”  The Federal Circuit continued this separation of written description from enablement in subsequent cases.  For example, in Vas-Cath Inc. v. Mahurkar, 935 F.2d 1555, 19 U.S.P.Q.2d 1111 (Fed. Cir. 1991), the court acknowledged that “it is possible for a specification to enable the practice of an invention as broadly as it is claimed, and still not describe that invention.”  Thus, the “written description” language of 35 U.S.C. § 112, ¶ 1 developed as a requirement that an applicant adequately describe the invention itself (i.e., showing that the applicant had “possession” of the subject matter claimed), which was severable and distinct from the requirement of enabling a person skilled in the art how to make and use it.

Nevertheless, despite consistent application by courts of a separate written description requirement, challenges and questions continued based on the legislative history and earlier court precedent.  But, application of the written description requirement in cases was usually limited to circumstances of “policing priority” with regard to whether elements or limitations added to claims were supported by an earlier original or parent filing.  However, in The Regents of the University of California v. Eli Lilly, 119 F.3d 1559, 43 U.S.P.Q.2d 1398 (Fed. Cir. 1997), the court applied the written description requirement to originally filed claims.  The court in Eli Lilly held that original claims written broadly to cover cDNAs encoding vertebrate insulin were not supported by the disclosure of only the rat insulin sequence.  The court concluded that a sufficient description of a genus may be achieved by means of a recitation of a representative number of species falling within the scope of the genus or by a recitation of structural features common to members of the genus that constitute a substantial portion of the genus.  The court in Enzo Biochem, Inc. v. Gen-Probe Inc., 323 F.3d 956 (Fed. Cir. 2002), reiterated that “the written description requirement is satisfied by the patentee’s disclosure of ‘such descriptive means as words, structures, figures, diagrams, formulas, etc., that fully set forth the claimed invention” but held that a deposit of biological material sufficiently supported the claims.  However, following Eli Lilly, questions lingered with regard to not only the existence of a separate written description requirement but its proper role and scope.

In the Ariad Pharmaceuticals Inc. v. Eli Lilly & Co. decision this year, the court sought to address these issues and put to rest any lingering questions about the legitimacy and scope of the written description requirement.  The court basically reaffirmed its position taken in prior cases that there is indeed a separate “written description” requirement that may be applied to the subject matter of original claims.  Given that this opinion was made en banc by the Federal Circuit, the Ariad decision is now the definitive statement on written description law jurisprudence unless the Supreme Court decides to intervene and grant certiorari.

In this case, Ariad Pharmaceuticals, Inc. (Ariad) brought suit against Eli Lilly & Co. (Lilly) alleging infringement of U.S. Patent No. 6,410,516 (the ’516 patent), and after trial, a jury found the claims valid and the defendant liable for infringement.  However, an earlier panel of the Federal Circuit reversed the District Court’s denial of Lilly’s judgment as a matter of law (JMOL) and held the claims of the ’516 patent invalid for lack of written description.  On rehearing en banc, the Federal Circuit reaffirmed its holding of invalidity for lack of written description.  In Ariad, the claims of the ’516 patent related generally to methods for reducing the effects and binding of NF-κB to recognition sites in the nucleus.  The specification of the ’516 patent provided little more than a hypothesis for three types of molecules with the potential to reduce NF-κB activity in cells:  decoy molecules, dominantly interfering molecules, and specific inhibitors.  The court found these disclosures as merely providing genus claims encompassing the use of any and all substances that achieve a desired result, and thus insufficient to provide a written description of the invention.

In its analysis, the court in Ariad first provided its statutory construction of the relevant language of 35 U.S.C. § 112, ¶ 1. The court entertained the different grammatical interpretations forwarded by each of the parties, but ultimately sided with Lilly’s parallelism argument in finding that a correct reading required that (1) “The specification shall contain a written description of the invention,” and (2) “[The specification shall contain a written description] . . . 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 make and use the same.”  The court rejected Ariad’s argument that the “written description of the invention” exists only to “identify” the claimed invention that must then be enabled.  The court further stated that Ariad’s reading of the statute would render portions of the statutory language unnecessary, thus violating a rule of statutory construction, and that Congress would have phrased the language of the statute differently if its intent was in accord with Ariad’s view.

The court in Ariad continued with a review of case law precedent.  The court first noted that Supreme Court cases have acknowledged the existence of a separate written description requirement, and that upholding the separate requirement is supported by a desire to fulfill the interests of stare decisis and not disrupt settled expectations.  The court then embarked on a review of its own opinions on written description over the years.  The court first dismissed Ariad’s arguments that the separate written description requirement was created by a misreading of the In re Ruschig decision and that pre-Ruschig decisions merely tested whether the specification identified the invention to be enabled.

In addressing whether the written description applies to original claims, the court again dismissed Ariad’s argument that the prior Eli Lilly decision had improperly extended written description beyond policing priority.  The court stated that there is no principled basis for such a restricted application and that Congress did not so limit the statute.  The court further stated that “while it is true that original claims are part of the original specification, that truism fails to address the question whether original claim language necessarily discloses the subject matter that it claims.”  The court then repeated the basic holding in Eli Lilly that claims defining the boundaries of a vast genus of chemical compounds, especially when defined in functional terms, may simply be a claim of a desired or useful result rather than a definition of what achieves the result.  The court continued “a sufficient description of a genus instead requires the disclosure of either 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.”  The court did caution, however, that functional language can meet the written description requirement when the art has an established correlation between structure and function.  The court then reaffirmed its similar prior holdings in Fiers v. Revel, 984 F.2d 1164, 25 U.S.P.Q.2d 1601 (Fed. Cir. 1993) (original claim language to “a DNA coding for interferon activity” failed to provide an adequate written description as it amounted to no more than a “wish” or “plan” for obtaining the claimed DNA rather than a description of the DNA itself), and Enzo Biochem, Inc. v. Gen-Probe Inc., 323 F.3d 956, 970 (Fed. Cir. 2002) (generic claim language appearing in ipsis verbis in the original specification does not satisfy the written description requirement if it fails to support the scope of the genus claimed).

Following this review, the court then proceeded to restate its position on written description law.  The court acknowledged that prior decisions have held that “the test for sufficiency is whether the disclosure of the application relied upon reasonably conveys to those skilled in the art that the inventor had possession of the claimed subject matter as of the filing date.”  However, the court stated its view that the term “possession” is not enlightening and incorrectly implies that a finding of written description may be supported by later showing a previously undisclosed “possession.”  Therefore, the court reformulated the test as “possession as shown in the disclosure” to emphasize that only “possession” as evidenced by the specification itself will suffice. In contrast to enablement, the question of adequate written description is a question of fact that will vary depending on the context.  “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.  For generic claims, we have set forth a number of factors for evaluating the adequacy of the disclosure, including [1] the existing knowledge in the particular field, [2] the extent and content of the prior art, [3] the maturity of the science or technology, and [4] the predictability of the aspect at issue.”

It is important to note that an adequate written description is measured by one of ordinary skill in the relevant art reading the specification, drawings and claims.  Therefore, an adequate written description for a particular element or feature may be found in circumstances where the particular feature may be supplied by the knowledge and understanding of one skilled in the art.  While the question of sufficient written description is decided on the facts of a given case, the court did provide a few basic principles that hold true across all cases:  “[1] the written description requirement does not demand either examples or an actual reduction to practice; [2] a constructive reduction to practice that in a definite way identifies the claimed invention can satisfy the written description requirement. Conversely, we have repeatedly stated that [3] actual ‘possession’ or reduction to practice outside of the specification is not enough.  Rather,  . . . it is the specification itself that must demonstrate possession.  And [4] 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.”

Chemical and biological inventions are commonly challenged on the basis of the written description and enablement requirements.  However, the court in Ariad rejected the notion that the written description requirement is a “super enablement” standard applied to chemical and biotechnology inventions.  Instead, the court insisted that the same written description standard is applied in all cases.  For example, the court stated that there is not a heightened requirement to provide an exact recitation of all biological sequences within the entire genus of claimed genetic material.  Rather, the disclosure of sufficient structural features common to members of the genus has always been permitted. In other words, the particularly stringent application of the written description requirement in chemical and biotechnology cases relates to the greater unpredictability in those fields rather than a different standard or application of the law per se in those cases.  In fact, the Ariad court cited Lizard Tech, Inc. v. Earth Res. Mapping, Inc., 424 F.3d 1052, 77 U.S.P.Q.2d 1161 (Fed. Cir. 2005) to show that the written description requirement is not always applied in chemical and biological inventions.

Finally, the court rejected Ariad’s argument that the written description requirement is met because the claims are directed to methods and not the molecules themselves.  The court cited University of Rochester v. G.D. Searles & Co., Inc., 358 F.3d 916, 69 U.S.P.Q.2d 1886 (Fed. Cir. 2004), holding that method claims were invalid for lacking an adequate written description because the specification did not describe any specific compound capable of performing the claimed method, and a skilled artisan would not be able to identify any such compound based on the specification’s functional description.  Thus, the written description requirement applies not only to composition claims, but also to method claims that necessarily depend on materials or compositions needed to carry out the claimed method.  In other words, some way of performing the claimed method must be described if not apparent to one skilled in the art, which in Ariad was dependent on the identity of the molecules needed to carry the method claims into effect.

Several long-standing principles relating to patent and claim drafting are reaffirmed by the court’s recent Ariad decision.  Best practices dictate that potentially claimed elements and features should be described to the fullest extent possible in the specification as filed to ensure adequate written description and enablement support that will withstand challenges during prosecution and litigation.  Although the court insisted that no different standard for written description is applied in chemical and biological cases, a review of court decisions will impress the fact that the written description requirement is applied with much greater frequency and scrutiny in chemical and biological cases due to the inherent unpredictability and uncertainty in these fields.  Therefore, when drafting applications, particularly for chemical and biological inventions, it is important that a full description of the elements and features of the claims, including how to make and use them, be provided in the specification with sufficient structural detail, including as many embodiments or examples as practically possible, to ensure that these requirements are met and that the claims are not later found invalid or rejected because the full scope of the invention is not adequately described or enabled.  Indeed, the quality and depth of patent protection for an invention often depends on how well the invention is described and how much information is disclosed in the originally filed application.  Particularly when an invention is directed to a chemical or biological composition of matter or a method relying on such a composition to carry out its steps, the specification should include a representative number of species or sufficient structural details including chemical formulas, biological sequences, etc., of those compositions forming a part of the invention in a manner sufficient to describe and enable the full scope of the claims in the eyes of a skilled artisan.