Archived — Track changes for MOPOP revised January 2017

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List of changes related to the incorporation of a new section detailing practice relating to antibodies.

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Section 17.07 - Title and paragraph

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17.07
Claims – January 2009

In claiming biotechnology inventions, many different approaches can be taken.  Here again, there are no special rules with respect to biotechnology.  A claim to a biotechnology invention must consequently be of definite and unambiguous scopeFootnote 1 must serve to distinguish the claimed invention from the prior art, must explicitly define all those features necessary to enable the person skilled in the art to realize the promised utility, and must be fully supported by the description.  The claims, individually and collectively, must be clear and concise and leave the reader in no doubt as to the nature of the invention.  These, collectively, are the usual requirements demanded by subsection 27(4) of the Patent Act and section 84 of the Patent Rules.

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Subsection 17.07.01 - Entire subsection

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17.07.01
Selections

Many inventions are predicated on the selection from a genus of one or several species.  The criteria for a proper selection were clearly stated by Maughan J. in the UK case IG Farbenindustrie AG's PatentsFootnote 2 and have been repeatedly cited with approbation in Canadian jurisprudence.Footnote 3

To be a proper selection, the matter of the selection must be:

  1. based upon a substantial advantage; and
  2. the whole of the selection must possess the advantage; and
  3. the advantage must be in respect of a special quality or character common to the whole of the selection.

An important consideration that must be borne in mind is that while embodiments being selected have been disclosed in some generic manner in the prior art, no embodiment falling within the scope of the claim can actually have been prepared. Per Maughan J., “[i]t must be remembered, of course, that the selected compounds have not been made before, or the patent would fail for want of novelty”.Footnote 4

A selection, therefore, is based entirely on the recognition by a later inventor of an advantage present in some subset of an invention more broadly disclosed in the prior art.  To be novel, the selection cannot encompass any embodiments that have been previously practiced.  To be inventive, the entire matter of the selection must possess the advantage.  To be a single inventive selection, the advantage must be in respect of a special quality or character common to the whole of the selection.

The utility of a selection depends on the presence of the “substantial advantage”, and it is this utility that the applicant must be in a position to establish by demonstration or sound prediction.  Note that the “substantial advantage” may be a disadvantage that is avoided by the selection.Footnote 5

Example:

  1. Prior art patent D1 discloses the utility of a known genus of polypeptides (genus A) for a new medicinal use (treating condition Y).

Claim:

  1. The use of polypeptide A1 for use in treating condition Y.

Analysis: consider that polypeptide A1 is a member of genus A which was not exemplified in D1.  Consequently, its therapeutic activity had not previously been conclusively demonstrated.  Consider that the application in question does not provide any exemplary data that polypeptide A1 has properties superior to those of other members of the genus in general. The application provides prophetic examples suggesting polypeptide A1 may be a suitable (even advantageous) alternative to the specific polypeptides mentioned in D1 as examples of genus A.  As the prophetic examples suggest the utility is being predicted, it appears there is no factual basis upon which the selection can be fairly based.  The matter of the claim, consequently, does not appear to be the result of an inventive step. Rather, it is an arbitrary selection of one of a group of equivalents known in general for the treatment of condition Y.

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Subsection 17.07.02 - Title and paragraphs 1-3

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17.07.02
Provisos

Applicants will sometimes exclude certain embodiments from their claims, usually to avoid inoperative embodiments, known prior art disclosures, or their own co-pending applications.

While the use of provisos is acceptable, the effect of the proviso on the application as a whole must be carefully considered.  Note that in the present discussion, the term “proviso” has been used as a generic term to refer to the exclusion of matter from a claim by negative limitation.  Whether the proviso is indicated using language such as “provided that A is not B”, “wherein X is not Y”, “any <generic element> except Q”, or some other form is not material.

The effect of a proviso on a claim will depend on the specific circumstances of each application, and should be carefully considered.  A proviso not disclosed in the application as filed, for example, has the potential of introducing subject-matter not reasonably to be inferred from the specification as originally filed, and consequently as being contrary to subsection 38.2(2) of the Patent Act.  No presumption exists that the introduction of a proviso not disclosed at filing is automatically the addition of new subject-matter.

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Subsection 17.07.02a - Entire subsection

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Subsections 17.07.02b, 17.07.02c, 17.07.03, 17.07.04 - Entire subsections

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17.07.02b
Provisos and unity

In certain cases, the presence of a proviso will call into question whether the remaining matter of the claims defines a single invention.  For example, if a claim defines the use of NSAIDs in combination with another drug to treat some disease, but it excludes ASA, a question arises as to the common general inventive feature upon which the unity of invention is based.  It is no longer the use of NSAIDs, since ASA is excluded.  This feature is no longer “common” to the invention.  It is not the use of a combination therapy to treat a disease, since unity cannot be predicated on a desired result to be achieved, but must rather be resident in the means of achieving the result.

17.07.02c
Provisos and non-essential elements

The situations referred to in the previous sections generally relate to the use of provisos to exclude embodiments that are members of broadly disclosed essential features (e.g. ASA from the essential element “NSAIDs”). Where a proviso is used to exclude in an arbitrary fashion some non-essential feature, this approach will generally not be sufficient to establish novelty or inventive step over the prior art.

Examples:

  1. A prior art journal publication D1 discloses murine and bovine growth factor polypeptides. The polypeptides are 85% and 87% identical over their entire length to a human growth factor (SEQ ID NO: 1) disclosed in the application in question.

Claim:

  1. A growth polypeptide comprising at least 80% identity to SEQ ID NO: 1, provided that said polypeptide is neither the polypeptide depicted below in (a) nor the polypeptide depicted below in (b):
    1. [murine growth factor amino acid sequence];
    2. [bovine growth factor amino acid sequence].

Analysis: consider that the proviso was introduced after D1 was cited against the claim. The addition of the proviso does not serve to render the claim patentable over the prior art.  D1 calls into question whether the matter of the post-proviso claim is based on a common inventive step in regards to the state of the art.  In view of D1, it would be obvious that many polypeptides having sequences within the claimed range would provide the same utility.

  1. Prior art application D1 discloses compound X as a useful drug in the therapy of disease Y.

Claim:

  1. A compound having <structural element A> for use in treating disease Y, provided said compound is not compound X.

Analysis: consider that at the time D1 was filed, the applicant did not know what structure led to compound X’s activity.  They have now discovered through further research what structure leads to the drug’s activity, and wish to claim other drugs related to X via this structure which are useful for the same purpose.  The proviso is acceptable in this instance, because the invention of claim 1 is not rendered obvious by D1 and the disclaimer is not arbitrary in nature.

17.07.03
Reach-through claims

The information in this subsection has been moved to section 17.11 of this manual.

17.07.04
Functional limitations

The information in this subsection has been moved to subsection 17.05.02 of this manual.

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Subsection 17.07.05 - Title and paragraphs 1-3

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17.07.05
Scope of claims

In order to fulfill their public notice function, a claim must define the invention in such a manner that the person skilled in the art will understand where they may and may not go without infringing.

As Lord Loreburn noted in Natural Kinematograph Co v Bioschemes Ltd, "[t]he patent system is designed to advance research and development and to encourage broader economic activity.  Achievement of these objectives is undermined however if competitors fear to tread in the vicinity of the patent because its scope lacks a reasonable measure of precision and certainty.  A patent of uncertain scope becomes a public nuisance"Endnotes 6.

An objection to a claim for ambiguity or lack of clarity as to its limits (indefiniteness) is made under subsection 27(4) of the Patent Act.  A claim is not indefinite simply because it is broad, but rather where the precise limits of the claim are uncertain.  A claim that relies, for example, on the use of "a polyol" is not indefinite since the person skilled in the art can immediately appreciate the scope of that term.  A claim relying on "a polyol capable of <performing some function>", however, is indefinite if the person skilled in the art would not know, or be able to reasonably predict or determine, what polyols fall within the scope of the claim.

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Subsection 17.07.05a - Entire subsection

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17.07.05a
Recourse to the description

During examination, the language of the claims is interpreted by giving each term its plain and usual meaning in the art to which the invention pertains unless it is clear from the description that a term in the claims is to be given a different meaning.

The courts have acknowledged that an applicant can act as their own lexicographer, by specifying in their description that certain terms will have particular meanings for the purposes of the application.  Whenever an applicant is desiring to act as their own lexicographer, however, it is incumbent on them to make this clear from the language of the description. Further, in so acting it is not proper to give a term having a well-known meaning a definition which is contrary to this meaning.  In such cases, uncertainty exists as to whether the term, when found in a claim, is intended to have its usual or distorted meaning.

For example, teaching that the term "up" means "down" for the purposes of the invention is only liable to cause confusion and serves no purpose.  Such a definition, when made in the description, would be objected to under subsection 27(3) of the Patent Act.  Further, the claim containing the term "up" is objected to under subsection 27(4) of the Patent Act for the lack of clarity as to whether the term is intended to actually mean "up", or rather to mean "down" following the teachings of the description. Similarly, teaching that the symbol "P" indicates nitrogen atoms is misleading; the symbol is recognized in chemistry as designating phosphorus, and could readily be replaced by the appropriate symbol "N" to designate nitrogen.  In contrast, teaching that the term "protein", for the purposes of the invention, has some specific but sensible meaning could be acceptable, especially where this avoids having to repeatedly include a lengthy definition in the claims.

Whenever inclusion of the definition found in the description into the claims would not be detrimental to the clarity and conciseness of the claim, however, this should be done.

It is worth noting that the courts, in construing the claims of a patent, are dealing with a document whose language is fixed.  Any deficiencies in the language of the claim can only be remedied by construing the claim in "an informed and purposive way".  During examination, in contrast, the language of the claims may be amended so as to remove ambiguity and maximize their usefulness in serving their public notice function of defining the extent of the monopoly soughtEndnotes 7.

Where a defect of clarity has been noted by an examiner in the language of a claim, it will generally be maintained in the face of a response arguing that the courts could, with the assistance of expert testimony, arrive at some construction thereof.  The purpose of the claims is to serve a public notice function, and "nothing can excuse the use of ambiguous language when simple language can easily be employed"Endnotes 8.

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Subsection 17.07.06 – Entire subsection

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Subsection 17.07.07, 17.07.07a – Entire subsections

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Section 17.08 – Entire Section

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17.08
Special topics - January 2009

This section concerns areas of biotechnology for which particular practices exist and which practices merit particular attention, elaboration or clarification.

17.08.01
Antibodies

Antibodies, as a class of chemical compounds, have been structurally and functionally well-characterized and it is known that, in general, immunization of a mammal with an antigen results in the production of antiserum containing antibodies reactive with the antigen.  Antiserum contains a generic family, genus or polyclonal mixture of antibodies where each individual antibody binds to an antigenic determinant or epitope carried on the immunizing antigen. The antiserum is representative of the entire family of antibodies capable of binding to the antigen.

As is the case with claims to any product or process, a claim to an antibody must be supported by a specification which (a) provides a written description of the antibody, and (b) would enable a person of skill in the art to produce the antibody.

17.08.01a
“Generic” and polyclonal antibodies

Methods for preparing polyclonal sera are well known in the art and a specification need not describe in detail any of these methods to be enabling.

With respect to written description, an antibody, like any other chemical compound, can be described in terms of its chemical structure (polypeptide sequence).  However, antibodies are rarely described this way. Indeed, it has become accepted practice to describe antibodies in terms of the antigen to which they bind and claims to antibodies often include functional language such as “capable of binding to”.  Therefore, a written description of an antibody can be provided by a written description of its antigen binding partner.  Since antigens are chemical compounds, the best way to describe an antigen is in terms of its chemical structure.  A description in terms of physical or chemical properties may be adequate provided that whatever properties are recited are sufficient to distinguish the antigen from other chemical compounds.

Since an antigen is implicitly understood to carry many epitopes, a written description of the antigen is akin to a written description of the collective of epitopes carried on the antigen and therefore provides a description of the corresponding generic or polyclonal binding partners.

If an application includes a claim to an antigen and a claim to an antibody reactive with the antigen, both claims should be commensurate in scope with respect to the antigen.

If the prior art teaches that antigen X is old, obvious or lacks utility, then antibodies reactive with that antigen would generally be considered obvious or lacking utility. Where the prior art discloses antibodies reactive with a close structural relative of antigen X, then a claim to “an antibody capable of binding to antigen X” may read on the old and known antibody by virtue of cross-reactivity and the claim may therefore be considered to be anticipated.

A claim to “an antibody capable of binding to antigen X” or “a polyclonal antibody capable of binding to antigen X” will generally be considered to be supported by a specification provided:

  1. antigen X itself has been adequately described; and
  2. either antiserum has been prepared, or where antiserum has not been prepared, there is neither anything peculiar about the antigen nor any indications that would lead a person of skill in the art to question the likelihood of success if that person desired to produce an antibody to the antigen.

Examples:

  1. The specification discloses a novel protein isolated from a bacterial pathogen, that has utility as a diagnostic target for detecting disease caused by the bacterium.  Further, the specification provides the amino acid sequence (SEQ ID NO: 1) of the protein, methods of purifying it using recombinant techniques, and methods of preparing antibodies to the protein by immunizing a suitable mammalian host.  No working examples of an antibody are provided. The protein appears to be a member of a new class of bacterial proteins and a sequence search reveals that the closest structural relative is 20% identical with no common domains of any significance.

Claim:

  1. An antibody capable of binding to the protein defined by SEQ ID NO: 1.

Analysis: The claim is acceptable.  Since the protein is new, useful as a diagnostic target, and exhibits little structural similarity to known proteins, antibodies prepared against it are likewise, new, useful and unobvious.  The specification is both enabling with respect to preparing antibodies and includes a written description (amino acid sequence) of the antigen.  The claim is therefore fully supported by the specification.

  1. The specification discloses a novel protein isolated from a bacterial pathogen, that has utility as a diagnostic target for detecting disease caused by the bacterium.  Further, the specification provides the amino acid sequence (SEQ ID NO: 1) of the protein, methods of purifying it using recombinant techniques, and methods of preparing antibodies to the protein by immunizing a suitable mammalian host.  No working examples of a novel antibody are provided.  The gene encoding the protein was cloned by immunoscreening a phage library with an old and known antibody reactive with a close homologue of the protein.

Claim:

  1. An antibody capable of binding to the protein defined by SEQ ID NO: 1.

Analysis:  The claim is objectionable. Despite the fact that the protein defined by SEQ ID NO: 1 itself appears to be novel, the claimed antibody is anticipated since the claim reads on the old and known antibody that has the requisite binding capability, i.e., the antibody used for immunoscreening.

  1. The specification discloses a correlation, identified by chromatographic analysis, between a novel hydrophobic peptide and a disease. The amino acid sequence of the peptide is provided and reveals that it is a low-molecular-weight member of a class of peptides to which no known antibodies have ever been prepared despite several attempts. The specification asserts that antibodies to the peptide may be prepared for eventual use in an immunoassay for the disease.  The specification does not provide any working examples of an antibody reactive with the peptide.

Claim:

  1. An antibody capable of binding to the peptide defined by SEQ ID NO: 1.

Analysis:  The claim is objectionable. No antibodies were raised against the novel peptide and the specification teaches that, despite several attempts, antibodies have never been raised against peptides of similar type. A person skilled in the art would not regard the specification as enabling the production of the claimed antibody.

17.08.01b
Monoclonal antibodies

A monoclonal antibody binds to a specific antigenic determinant or epitope carried on an immunizing antigen.  A monoclonal antibody can be viewed as one member of the family of polyclonal antibodies contained in antiserum produced by an immunizing antigen.

As with claims to polyclonal antibodies, a claim to a monoclonal must be supported by a specification that is both enabling and includes an adequate written description of the antibody.

The core steps for preparing monoclonal antibodies are now well-known and established.  Thus, for a specification to be enabling, the polypeptide antigen against which the monoclonal is raised must be described but an applicant need not set out a detailed procedure for producing the antibody.  A detailed step-by-step protocol would only be necessary if the invention resides, at least in part, in an applicant having adapted known procedures to overcome some difficulty in making a monoclonal to a particular antigen.

An examiner will consider the following when determining whether a specification is enabling with respect to monoclonal antibodies:

  1. whether the applicant actually prepared a monoclonal antibody;
  2. where a monoclonal antibody has not been prepared,
  3. whether the antigen and core steps for preparing the monoclonal are described,
  4. the availability and/or ease of production of the antigen,
  5. whether there are indications that the applicant was unable to produce a monoclonal antibody or to suggest that one of skill in the art would not be able to reproducibly make a monoclonal to the subject antigen,
  6. whether there are indications which suggest that undue experimentation or undue adaption of known core steps would be necessary for preparing a monoclonal.

The foregoing list is non-exhaustive and non-cumulative and is intended as a guide only.  Each application will be considered on its own merits.

A specification must not only be enabling with respect to a claimed monoclonal antibody but also must provide a written description of the antibody.  The written description requirement is satisfied where a specification describes at least one monoclonal and it is evident that the applicant was in possession of the antibody at the time the patent application was filed.  Reference to a biological deposit of either a hybridoma or a monoclonal antibody is the best way to demonstrate possession.

Applicants should note however, that a deposit for patent purposes, i.e., for consideration in determining whether or not subsection 27(3) of the Patent Act has been complied, must be in accordance with sections 104 to 106 of the Patent Rules.

An adequate written description of a monoclonal antibody can also be provided by an explicit description of the epitope to which it binds in the same way as a written description of a generic antibody or polyclonal can be provided by a general description of an antigen.  As discussed in section 17.08.01a, a written description of the antigen amounts to a written description of the collective of epitopes carried on the antigen and therefore provides a description of the family of polyclonal binding partners.  Since a monoclonal is one member of the family which binds to a specific epitope, if it is to be described in terms of its binding partner, the specification must include a structural description of the epitope.

An epitope on a protein can be described in terms of a specific amino acid sequence which is a subset of the complete polypeptide sequence of the protein, or as a binding pocket defined by specific non-contiguous amino acids.

Where existence of an epitope has not been demonstrated but rather is predicted, for example by computer modelling, a specification must disclose not only a structural description of the epitope, but also a factual basis and sound line of reasoning to support the prediction of a putative antibody binding site.

An examiner will consider the following when determining whether a specification provides a written description with respect to monoclonal antibodies:

  1. whether the applicant was in physical possession of a monoclonal antibody at the time of filing;
  2. whether the applicant had made a deposit of a hybridoma or monoclonal antibody for patent purposes or was in a position to do so at the time of filing;
  3. whether there is specific structural description of an epitope or epitopes carried on the antigen to which the monoclonal will bind.

The foregoing list is non-exhaustive and non-cumulative and is intended as a guide only.  Each application will be considered on its own merits.

Where the prior art discloses a monoclonal antibody specific for antigen X, a broad claim would not be acceptable as it would read on the prior art.

A prior art document which merely describes how a monoclonal antibody to an antigen might be prepared yet does not specifically describe such a monoclonal antibody, is not considered an anticipatory document against an application that claims and specifically describes a monoclonal antibody.

Example:

  1. The specification discloses a novel isolated protein from a bacterial pathogen that has utility as a diagnostic target for detecting disease caused by the bacterium. Further, the specification provides the amino acid sequence (SEQ ID NO: 1) of the protein, methods of purifying it using recombinant techniques as well as methods of preparing monoclonal antibodies to the protein by using traditional techniques. The specification describes neither an actual monoclonal antibody, nor a paratope thereof, nor a specific epitope of the protein.

Claim:

  1. A monoclonal antibody capable of binding to the peptide defined by SEQ ID NO: 1.

Analysis: The claim is objectionable.  Although the specification is enabling with respect to preparing a monoclonal antibody capable of binding to the antigen, there is no written description of such a monoclonal. The specification does not disclose that the applicant was in possession of a monoclonal antibody nor does it disclose a structural description of a specific epitope where a putative monoclonal antibody would bind.

17.08

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Endnotes 17.07 - All endnotes

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