By Christopher P. Singer --
In April, 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). Continuing our review, Patent Docs provides an overview of the example covering aspects of protein variants.
Example 9 – Protein Variants
Example 9 contains two claims directed to an isolated protein of a particular sequence (SEQ ID NO: 3) or a variant thereof. This Example is essentially unchanged from the variant example in the former written description guidelines (presented therein as Example 13). The exemplary claims recite:
Claim 1: An isolated protein comprising the amino acid sequence shown in SEQ ID NO: 3.
Claim 2: An isolated variant of the protein of claim 1.
The hypothetical specification discloses that applicant had isolated from liver a 65 kDa protein that has tumor necrosis activity. The specification also provides the protein sequence (SEQ ID NO: 3). The specification states that the invention provides protein variants of SEQ ID NO: 3 having one or more amino acid substitutions, deletions, insertions, and/or additions, and that making such protein variants is routine in the art. However, the specification fails to include any further description of the claimed variants and also fails to define when a sequence is no longer a variant of SEQ ID NO: 3.
Not surprisingly, claim 1 is adequately supported by the written description because the specification provides SEQ ID NO: 3, the structure of which is present within the entire genus of proteins encompassed by the claims (e.g., fusion proteins comprising SEQ ID NO: 3). Those skilled in the art, given the disclosure in the specification and general knowledge in the art, would recognize that the applicant was in possession of the invention recited in claim 1.
The fate of claim 2 is not as rosy. The Office's analysis goes to great lengths to discuss the many shortcomings of the hypothetical disclosure and concludes that claim 2 lacks adequate written description. The analysis concedes that pre-existing knowledge in the art adequately supplements the description as far as addition variants are concerned (e.g., fusion proteins as supported for claim 1). Regarding the inadequacy of the disclosure, the Office notes that the disclosure (1) places no limit on the number of amino acid substitutions, deletions, insertions and/or additions; (2) fails to describe the complete structure of any members of the genus encompassed by claim 2; (3) fails to describe the physical or chemical characteristics for any substitution, deletion, or insertion variants; (4) fails to disclose any correlation between the structure of the variants and the disclosed SEQ ID NO: 3; and (5) fails to correlate structure with function of any variant. Consequently, the Office states that the specification fails to satisfy the written description requirement for Claim 2.
It is particularly difficult to derive anything useful from this example. Beyond the conclusion that fusion proteins are well known in the art and are supported with minimal disclosure, the Office provides no guidance for an application that contains any amount of significant disclosure regarding variants. This example in particular seems to suggest that written description can be satisfied only for that which is explicitly disclosed and exemplified in the specification.
For additional information on this topic, please see:
• "Antisense," May 13, 2008
• "Antibodies to a Single Protein & Antibodies to a Genus of Proteins," May 12, 2008
• "ESTs & Partial Protein Structures," May 8, 2008
• "DNA Hybridization & Percent Identity," May 6, 2008
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