Case law regarding written description is in a state of flux so it is beneficial for the patent practitioner to understand some key Federal Circuit decisions involving the written description requirement.

One might ask why a separate written description of the invention is needed in the specification when the claims are there to define the subject matter of the invention. The reason is historical.

Most of the language of the current statute, 35 U.S.C. §112(a) (2012), came from the Patent Act of 1793, which required a written description of the invention but did not require claims. The Act stated the invention must be described in such full, clear and exact terms so as to enable any person skilled in the art to make, compound, and use the same. The purpose of the specification was to enable the skilled worker to make and use the invention and to put the public in possession of the new invention. Patent Act of 1793, Ch. 11, 1 Stat. 318-323 (1793). Incidentally, the requirement for claims came about in Patent Act of 1836.  Patent Act of 1836, Ch. 357, 5 Stat. 117 (1836).

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 or joint inventor, of carrying out his invention. 35 U.S.C. §112a (2012)(emphasis added).

The language of the current section 112 is almost identical to that written in 1793. There are three requirements: the first is that the specification contains a written description of the invention. The second is that the specification describes the manner and process of making and using the invention, which is the enablement requirement. The third is that the specification sets forth the best mode of the invention. These three requirements are separate and distinct from each other.

The goal of the written description requirement is to clearly convey that the applicant has invented the subject matter as claimed. The Applicant must disclose his invention to the public in exchange for patent rights, the quid pro quo of patent law. This disclosure helps the USPTO to examine the application and the Courts to construe the claims. The public not only learns of the invention but also of the boundaries of the invention for non-infringement purposes. “A description of the claimed invention allows the …[PTO] to examine applications effectively; courts to understand the invention, determine compliance with the statute, and to construe the claims; and the public to understand and improve upon the invention and to avoid the claimed boundaries of the patentee’s exclusive rights.” Ariad Pharm., Inc. v. Eli Lilly & Co., 598 F.3d 1336, 1345 (Fed. Cir. 2010).

The essence of the matter is whether the USPTO and the Courts are convinced that the inventor possessed the invention when he filed for a patent. Satisfaction of the written description requirement ensures that the claimed subject matter was sufficiently disclosed at the time of filing so that the prima facie date of invention can be held to be at least the filing date of the application.

It doesn’t matter if the disclosure is found in the specification, abstract, or the drawings, as long as it is there on the filing date of the application. Vas-Cath Inc. v. Mahurkar, 935 F.2d 1555, 1563 (Fed. Cir. 1991). Look to the “four corners of the specification” for adequate disclosure. Ariad, 598 F.3d at 1366. A mere wish or plan for obtaining the claimed invention does not satisfy the written description requirement.

Some considerations of the Examiners and Courts are: Has there has been an actual reduction to practice? Was there a deposit of biological material at an approved government depository? Are examples provided? Is there a drawing? How about a structure? For chemical and biotech cases, are there chemical formulas, physical or chemical properties or structure-function correlations? How about sequences, binding affinity, specificity or molecular weight? Is the method of making disclosed?

Other issues often considered are the level of skill and knowledge in the art. That which is conventional and well-known to one of ordinary skill does not have to be described in detail. Likewise, predictable aspects do not need an exhaustive description.

Lack of written description is the one of the most common rejections of the claims and one of the most frequently debated in litigation.  The threshold for satisfying written description is not clear because there are no bright line rules. The rules change with each invention, depending on the nature and scope of the claims, and with the state of the art at the time, including the existing knowledge in a particular field, the extent and content of the prior art, the maturity of the technology, and the predictability of the matter at issue.

In addition, most case law focuses on what is NOT required rather than what is suitable. However, two sources of general guidelines are available: Written Description Training Materials 2008 and Supplementary Examination Guidelines for Determining Compliance with 35 U.S.C. §112 and for Treatment of Related Issues in Patent Applications 2011.

Key Cases

Here are some key cases that focus on written description.

In Ariad, the Court held that actual reduction to practice is not required in order to satisfy written description. Ariad, 598 F.3d at 1352. This biotech case dealt with regulation of gene expression. The claims were for a genus of compounds that reduce the activity or binding of the transcription factor, Nuclear Factor Kappa B, to certain genes. The specification failed to disclose any species that accomplishes that result or any working or prophetic methods that accomplishes that result.  Such claims merely recite a description of the problem to be solved, while claiming all solutions to the problem, AND covering any compound later invented and falling within the claims’ boundaries.  A description that merely renders the invention obvious does not meet the requirement.

Like Ariad, the next case, Streck held that examples are not needed in order to satisfy the written description requirement. Streck, Inc. v. Research & Diagnostic Sys., Inc., 665 F.3d 1269, 1285 (Fed. Cir. 2012). This is another biotech case that dealt with red blood cells and analogs thereof. Here the Federal Circuit said that the specification need not provide an actual reduction to practice of the invention, it need only show a constructive reduction to practice that in a definite way identifies the claimed invention.

There is no particular form of disclosure that is required, according to the next case. Carnegie Mellon Univ. v. Hoffmann-La Roche, Inc., 541 F.3d 1115, 1122 (Fed. Cir. 2008). In this case, the applicant claimed a gene coding for the expression of DNA polymerase I enzyme but only described one species, the E. coli polA gene. Because DNA polymerase I is a related group of enzymes encoded by a related group of genes which themselves contain variation, the Federal Circuit held that this narrow description did not adequately support a broad claim to a gene from any bacterial source.

The case of In re Lukach held that there is no need for ipsis verbis or word for word disclosure of the claims in the specification. In re Lukach, 442 F.2d 967, 969 (C.C.P.A. 1971). In that case, the specification described a genus of copolymers having a narrow weight distribution and the claims recited a Mw/Mn ratio of 2-3. The term “Mw/Mn” was not mentioned in the specification. Mw/Mn is an alternate way of describing the size of a mixture of polymers having different molecular weights. The Court said that there was no support for the claims, which recited a Mw/Mn ratio. The Federal Circuit also discussed the fact that the description of a single embodiment constitutes a description of the invention for anticipation purposes but the same information might not be enough to satisfy the written description requirement. There is a difference between a “claim anticipating disclosure” and a “claim supporting disclosure.”  Lukach, 442 F.2d at 969-70.

In the next case, the University of Rochester, the Court stated that express disclosure of every species of a genus is not required.  University of Rochester v. G.D. Searle & Co., Inc., 358 F.3d 916 (Fed. Cir. 2004). Also, the Federal Circuit said that where there is substantial variability within the genus, there must be a sufficient number and variety of species to reflect the variations within the genus. In this case, the claims recited “a non-steroidal compound that selectively inhibits activity of the PGHS-2 gene” but no compound was disclosed, nor method of making one. University of Rochester, 358 F.3d 918.

As demonstrated by the cases just described, much of the current debate about the appropriate scope of the written description requirement arises from chemistry and biotechnology matters. Most often, the issue of lack of adequate written description comes about when an original claim is not described sufficiently; or when a new or an amended claim is not supported by the application as filed; or when priority is claimed to an earlier-filed foreign or U.S. application under 35 USC § 119, 120, or 365(c).

There is a strong presumption that an adequate written description is present when the application is filed. In re Wertheim, 541 F.2d 257, 263 (C.C.P.A. 1976). It is presumed that you have the “invention” in hand when a patent application is filed.  It is then up to the USPTO to present evidence why a person of ordinary skill would or would not recognize written description of the claimed invention.

The analysis of whether written description is satisfied begins with a comparison of the claims to the invention disclosed in the specification. If the claimed invention is not supported by the specification, the claim does not meet the written description requirement, and the claim fails.

In an early case decided in 1967, In re Ruschig, a claim was added during prosecution to recite a specific chemical compound, chlorpropamide. In re Ruschig, 379 F.2d 990,991 (C.C.P.A. 1967). The specification, as filed, disclosed a genus of about a half-million possible compounds, which included chlorpropamide, but chlorpropamide was not specifically described. The Federal Circuit found that the claim was not supported by the specification because the specification failed to provide guidelines that pointed to chlorpropamide precisely. It was just one of the half-million possibilities listed.

Another chemical case dealing with a laundry list of possibilities is Fujikawa vs. Wattanasin. There the Federal Circuit discussed whether there was sufficient written description in the specification to support a proposed count in an interference.  Fujikawa v. Wattanasin, 93 F.3d 1559, 1571 (Fed. Cir. 1996). The count referred to one particular chemical molecule, a mevalonolactone. The specification disclosed a colossal genus of multi-ring chemical molecules having multiple R groups, where each of the multiple R groups in turn could be multiple chemical substituents. Fujikawa, 93 F.3d at 1570.

Although all of the chemical substituents of that particular chemical molecule of the count were adequately disclosed in the specification, there were no guidelines that would lead one of ordinary skill to that particular chemical molecule claimed. Simply describing a large genus of compounds is not sufficient to satisfy the written description requirement. The Federal Circuit provided some suggestions as to what might have been helpful to include in the specification, such as listing preferred molecules and describing why they are preferred.

Another key case, also pertaining to chemistry and biotech, is Amgen v. Chugai. There the Federal Circuit found that a claim to an isolated DNA sequence, encoding a certain protein, requires a structural definition of the DNA sequence itself, because the DNA sequence is a chemical compound. Amgen, Inc. v. Chugai Pharmaceutical Co., 927 F.2d 1200, 1206-07 (Fed. Cir. 1991).  The DNA sequence cannot be properly defined by solely describing its principal biological property.  As an aside, whether isolated DNA is patentable is now being hotly debated, but at the time, isolated DNA was patentable.

One more DNA case is Regents of the University of California v. Lilly. There the Federal Circuit found that the originally-filed claims to cDNA encoding human insulin were invalid for lack of written description because the specification did not include the nucleotide sequence of the human cDNA. Regents of the Univ. of Cal. v. Eli Lilly & Co., 119 F.3d 1559, 1566 (Fed. Cir. 1997). The rat cDNA sequence was disclosed, the method of obtaining the human cDNA was described in a prophetic example, and the amino acid sequences of human insulin were disclosed. The Court said that these matters do not describe the human cDNA itself. The Court further said that the description of the rat insulin cDNA is not a description of the broad genus of mammalian insulin cDNA. The Court also talked about “visualizing” the particular species of the genus and how it could not visualize the human cDNA sequence.

In a more recent case, University of Rochester v. G.D. Searle & Co., also chemical, the Federal Circuit held that claims to a non-steroidal compound that specifically inhibited a component involved in inflammation were invalid for lacking written description because the compound was only described functionally. Univ. of Rochester, 358 F.3d 916, 923-929 (Fed. Cir. 2004). Written description is insufficient unless one of ordinary skill can recognize the identity of the claimed compound and the description must convey what the compound is, not just what it does.

Earlier this year, the Federal Circuit decided another key case about written description in AbbVie v. Janssen Biotech. The claims at issue pertained to an isolated human antibody that binds to an antigenic protein where the antibody has a dissociation constant of 1 x 10-2 s-1 or less.  AbbVie Deutschland GmbH & Co. v. Janssen Biotech, Inc., 759 F.3d 1285, 1292 (Fed. Cir. 2014). The antigenic protein was human interleukin 12, which causes psoriasis and rheumatoid arthritis.  Here the claims defined the antibody by its function, how quickly it dissociates from human interleukin 12.

The facts are that the specification described about 300 human antibody sequences that bound to human interleukin 12. AbbVie, 759 F.3d at 1292. The binding affinities of those 300 antibodies were also disclosed. One would think that the disclosure of 300 species would be enough to satisfy the written description requirement for a genus claim. In spite of this, the Federal Circuit found that disclosure lacked sufficient written description.

In its analysis, the Court noted that the specification did not disclose structural features common to members of the claimed genus. Also, the Court posed the question as to whether the specification disclosed sufficiently described representative species to support the entire genus. AbbVie, 759 F.3d at 1299-1301.

The Court noted that the genus here was very large and analogized the genus to a plot of land.  AbbVie, 759 F.3d at 1300. The disclosed species here only described one corner of the land so that disclosure was not representative of the entire plot of land. The Court said that one describes a plot of land by its furthest coordinates, as in erecting a fence around it, which fence is the claims. However, erecting the fence around a genus is not a description of the genus. This is no more than a research plan, leaving it to others to explore the unknown areas.

It was found that the specification described only one type of structurally similar antibody that shared a 90 percent or more amino acid sequence similarity. In fact, more than 200 of those 300 antibodies differed by only one amino acid. The Court said that those antibodies were not representative of the full variety and scope of the genus. Janssen, meanwhile, created antibodies that also bound human interleukin 12, but were significantly different than those described by AbbVie, both in structure and sequence.

The Court said that although the number of species disclosed in the specification appears quantitatively high, the species are very similar and do not qualitatively represent other types of antibodies encompassed by the genus. The specification must adequately describe representative antibodies to reflect the structural diversity of the genus. AbbVie, 759 F.3d at 1301.

Lastly, the issue of lack of written description can also arise when priority is claimed to an earlier application, be it U.S. or foreign. This situation of whether the claimed invention is properly disclosed in an earlier filed application is highly litigated because it deals with the applicability of prior art. “Under 35 U.S.C. 119, the claims set forth in a United States application are entitled to the benefit of a foreign priority date if the corresponding foreign application supports the claims in the manner required by 35 U.S.C. § 112, paragraph 1.” In re Gosteli, 872 F.2d 1008 (Fed. Cir. 1989) citing In re Werthheim, 541 F.2d 257, 261 (C.C.P.A. 1976).

In re Gosteli deals with another chemical patent where the claims defined something different than that which was disclosed in the earliest-filed patent application, filed in Luxemborg. The disclosure of the Luxemborg application was not as complete as that of the later-filed U.S. application, which claimed the benefit of the Luxemborg filing date. The Court said that there was not sufficient written description of the U.S. claims in the Luxemborg application so the U.S. application was not entitled to the earlier Luxemborg filing date. The U.S. application, therefore, did not to antedate an anticipatory reference asserted by the Examiner, and the U.S. claims were found to be invalid.

In conclusion, some of the most important issues discussed in key Federal Circuit cases regarding written description have been reviewed. The rationales described in these cases can be valuable in designing strategies for the prosecution and litigation of patents in the United States.