Inventions pertaining to antibodies, particularly monoclonal antibodies, may be protected if proper support is provided within the specifi cation and the antibodies are enabled. This article will outline how patenting of antibodies differs across jurisdictions and how Canada compares.

Until recently, Canadian practice relied on a Commissioner’s Decision pertaining to the support required for claims to monoclonal antibodies. 1 In this case, the antigen was fully characterized, yet no monoclonal antibodies were prepared. The specifi cation made reference to the use of “traditional techniques” for the production of monoclonal antibodies. The Commissioner acknowledged that methods to make monoclonal antibodies into various antigens were known, yet concluded:  

No specifi c description of the monoclonal antibodies in claim 84 or a process for their preparation is disclosed . . . Describing and identifying the antigens does not provide support for the hybridoma or the monoclonal antibodies nor does it provide suffi cient instruction on how to make the antibodies.2

How Canada Compares

This is substantially different from the position adopted by the United States Patent and Trademark Offi ce. In Noelle v. Lederman, the U.S. Court of Appeals noted if a protein is known to be immunogenic, and the antigen is characterized “either by its structure, formula, chemical name, or physical properties, or by depositing the protein in a public depository, the applicant can then claim an antibody by its binding affi nity to that described antigen.”3 Therefore, there is no requirement to have produced the antibody, including a monoclonal antibody, to provide support for a claim to the antibody, although the antigen to which the antibody binds must be fully characterized. This position has been successfully challenged in a recent decision in Centocor v. Abbott Laboratories.4

The courts in the United Kingdom have also recognized it generally does not require undue effort to make and identify monoclonal antibodies that are capable of specifi cally binding to a novel and defi ned polypeptide.5  

In terms of enablement in both the U.S. and the U.K., deference is usually given to the applicant/ patentee in view of the maturity of the monoclonal antibody fi eld. Concerns may arise, however, if little is known about the polypeptide’s function, or in cases involving therapies or diagnostics.  

Developments in Canadian Practice

As a result of a further Commissioner’s Decision,6 the Canadian practice is perhaps moving closer to international practice. The application in question, which has now issued as Canadian patent 1,341,598 to Central Sydney Area Health Service, related to a subunit polypeptide of an insulin- like growth factor binding complex. The applicant attempted to claim antibodies including monoclonal antibodies, although no antibodies were prepared. The decision in this case was not to allow the monoclonal antibody claims, but the decision did provide guidance on what the offi ce will consider when determining if an application meets the written description and enablement requirements in respect of monoclonal antibodies.

The Commissioner provided the following non-exhaustive list of elements useful in determining whether a specifi cation is enabled for a monoclonal antibody capable of binding to a polypeptide:  

  • Whether there is a description of the polypeptide and knowledge of its real or expected immunogenicity;  
  • Whether the scope of an antibody claim in respect of the polypeptide is appropriate;  
  • The availability and/or ease of production of the polypeptide;  
  • Whether a monoclonal antibody was actually prepared;  
  • Whether there are indications of success or failure on record;  
  • Whether there are indications on record which suggest a requirement for undue experimentation or undue adaptation of the known core steps of preparing a monoclonal antibody; and  
  • Whether there are indications on record which suggest irreproducibility of an actual or proposed method of preparing a monoclonal antibody.  

The Commissioner also provided a non-exhaustive list of factual considerations useful in determining whether the specifi cation provides an adequate written description of a monoclonal antibody capable of binding to a polypeptide:  

  • Whether there is a more than merely a general description of the polypeptide, including an explicit description of specifi c epitopes on the polypeptide;  
  • Whether there is a description of a paratope of a monoclonal antibody;  
  • Whether the scope of an antibody claim in respect of the polypeptide is appropriate;  
  • Whether the applicant was in physical possession of a monoclonal antibody; and  
  • Whether the applicant was in a position to provide a biological deposit of a hybridoma producing a monoclonal antibody at the time of fi ling.  

In a further Commissioner’s Decision,7 the Patent Offi ce allowed claims to a monoclonal antibody based on the novelty and full characterization of the polypeptide, despite the fact the monoclonal antibodies had neither been disclosed nor deposited. The Commissioner stated:  

[W]here the antigen is a novel polypeptide and has been fully characterized, for example by complete amino acid sequence, an applicant can then claim monoclonal antibodies that are immunoreactive with the polypeptide without the applicant actually having made or deposited a specifi c embodiment.8  

On the issue of utility, the monoclonal antibodies would have the ability to bind to the immunizing antigen. This utility is self-evident. Therefore, a skilled person would recognize that the monoclonal antibody would have at least one utility. On this point, the Commissioner acknowledged and adopted the teaching in Consolboard Inc. v. Mac- Millan Bloedel (Saskatchewan) Ltd.9 and said:  

[S]o long as utility would be apparent to the skilled person, neither the description nor the claims need explicitly mention the utility of a novel product claimed as such.10

Clearly, each application will be examined on its own merit. However, it is encouraging to see that the Patent Offi ce is adopting a practice that is accepted internationally and will consider factors other than the physical possession of the monoclonal antibody when determining support and utility.