By Christopher P. Singer --
Last month, the U.S. Patent and Trademark Office announced
that it had updated the training materials to be used by examiners in
the examination of patent applications for compliance with the written
description requirement of 35 U.S.C. § 112, first paragraph. The revised training materials supersede and replace the previous set of training materials
issued by the Patent Office in 1999. The new training materials
provide seventeen examples, of which fourteen are specifically related
to biotech inventions. In particular, the biotech-specific examples
address expressed sequence tags (ESTs) (example 4), a partial protein
structure (example 5), DNA hybridization (example 6), allelic variants
(example 7), bioinformatics (example 8), protein variants (example 9),
a product claimed by its function (example 10), a polynucleotide or
polypeptide sequence sharing percent identity with another sequence
(example 11), antisense oligonucleotides (example 12), antibodies to a
single protein (example 13), antibodies to a genus of proteins (example
14), a genus with widely varying species (example 15), a process claim
where novelty resides in the process steps (example 16), and methods of
using compounds claimed by functional limitations, methods of
identifying compounds, and compounds identified by such methods
(example 17). Patent Docs continues the discussion of these examples, reviewing Examples 13 and 14 drawn to antibody technology.
Example 13 – Antibody to a Single Protein
Example 13 provides guidance for a single exemplary claim directed to an isolated antibody that binds to an isolated and structurally characterized antigen. This Example is essentially identical to the prior guidance in the former written description guidelines (presented therein as Example 16). Nevertheless, the single claim presented in the new training materials recites:
Claim 1: An isolated antibody capable of binding to antigen X.
The fact pattern of this example states that the specification discloses that "antigen X" was isolated from HIV and is useful for detection of HIV infection. The specification describes purification of antigen X by gel filtration and discloses its amino acid sequence. The specification also discloses that antigen X is a 55 kDa monomer, has no disulfide bonds, and has a slightly acidic pI. While the hypothetical specification discusses antibodies that specifically bind to antigen X and states such antibodies can be used in immunoassays to detect HIV, the specification lacks a working or prophetic example of an antibody that binds to antigen X. Nevertheless, given the level of skill and knowledge in the art of antibodies at the time the application was filed, production of antibodies against a well-characterized antigen was routine, and therefore the specification satisfies the written description requirement of § 112, first paragraph, with respect to the full scope of claim 1.
While the example fails to provide a specific filing date for the specification, it cites to the 1976 reference of Elvin A. Kabat ("Structural Concepts in Immunology and Immunochemistry," 2nd Ed. (Holt, Rinehart and Winston)) to provide evidence of the knowledge in the art that antibodies can be generated from isolated antigens, that the various isotypes (IgG, IgA, IgM, IgD, and IgE) share certain physical, chemical, and biological properties, and that there is sequence variation in the variable and hypervariable regions of the antibody sequence. Thus, even though the specification fails to describe (a) any partial physical or chemical properties (e.g., molecular weight, association constant); (b) a partial structure of the claimed antibody by sequence, reference to a deposit, or in the drawings; (c) any functional correlation of antibody structure to binding activity to antigen X; and (d) any method for making an antibody that binds antigen X, the production of such antibodies is so conventional that the amount of disclosure present in this specification is adequate to demonstrate possession of the claimed antibody.
Example 14 – Antibodies to a Genus of Proteins
Example 14 is based on the fact pattern of the 2004 Federal Circuit case, Noelle v. Lederman, 355 F.3d 1343 (Fed. Cir. 2004), and provides guidance for three exemplary claims directed to antibodies that bind to "Protein X" which was isolated from murine tissue and has been structurally characterized. This Example is new relative to the prior written description training materials. The three presented claims in this Example recite:
Claim 1: A monoclonal antibody that binds Protein X.
Claim 1: The antibody of claim 1 which binds murine Protein X.
Claim 3: The antibody of claim 1 which binds human Protein X.
The fact pattern of this example states that the specification describes a monoclonal antibody that specifically binds to Protein X isolated from murine tissue, and protocols for producing anti-Protein X antibodies. Protein X is disclosed as being located on the surface of certain immune cells and is asserted to be useful for treating immune disorders involving cell signaling. The specification describes purification of murine Protein X and discloses its amino acid sequence. The specification does not disclose any physical or chemical property for Protein X from any other species (e.g., no disclosure of molecular weight or cross-reactivity of human Protein X with anti-murine Protein X antibodies, and no sequence information for Protein X from any species other than mouse). The specification does state that human Protein X is expected to have the same in vivo function as murine Protein X, and that antibodies to human Protein X will be useful for treating immune disorders involving cell-to-cell signaling.
Not surprisingly, the written description requirement for claim 2 above is completely satisfied by the disclosure in the specification, essentially for the same reasons provided in Example 13 (adequate description of the purified antigen satisfies written description for antibodies which bind the purified antigen).
As to claim 3, the lack of any physical or chemical description of an antibody that binds human Protein X, along with the lack of any physical or chemical description of human Protein X leads to the conclusion that written description is not satisfied for this claim. As detailed in the analysis, the specification and prior art fail to provide any evidence that the disclosed properties of murine Protein X are predictive of the properties of human Protein X. Further, the disclosure of human Protein X in the specification is purely functional and fails to provide any correlation to physical and chemical properties. As stated in the materials, "Claim 3 is directed to an unknown that is identified only by reference to another unknown."
Similarly, the specification fails to provide written description for the full scope of claim 1, because the claim relates generically to many species of monoclonal antibodies that specifically bind to Protein X from any species. While the specification adequately describes murine Protein X and therefore an antibody that binds murine Protein X, it fails to provide any physical or chemical description of Protein X from any other organism, and fails to describe a method of making an antibody that binds non-murine Protein X without first having the particular non-murine Protein X in hand. Thus, because claim 1 is generic to antibodies to Protein X from a variety of organisms, and the specification fails to describe anything other than murine Protein X, claim 1 does not satisfy the written description requirement. The analysis notes, without further clarification, that if any evidence was presented that murine Protein X was representative of the genus of Protein X molecules from other species, it is possible that claim 1 could meet the written description requirement.
For additional information on this topic, please see:
• "ESTs & Partial Protein Structures," May 8, 2008
• "DNA Hybridization & Percent Identity," May 6, 2008
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