On June 29, 2015, the Canadian Intellectual Property Office (CIPO) released guidance for examination of diagnostic method claims: Practice Notice: Examination Practice Respecting Medical Diagnostic Methods – PN 2015-02.

In the Practice Notice, CIPO has adopted a problem and solution approach to analyzing claims to diagnostic methods, summarized below. 

Problem

Based on the description and the examiner’s understanding of the common general knowledge in the art, the examiner should first identify the problem(s) the inventors set out to solve. The Practice Notice discusses two types of problems – a “data acquisition problem” and a “data analysis problem” – and provides non-exhaustive factors that may indicate their existence.

A data acquisition problem may be indicated, for example, by disclosure relating to an analyte that is not common general knowledge, or by significant detail or emphasis relating to how to identify or quantify a particular analyte. 

A data analysis problem may be indicated, for example, by emphasis on the discovery of a new correlation between a condition and an analyte that is common general knowledge, with relative absence of technical details on how to acquire data about the analyte, or by indication that it is common general knowledge to apply means contemplated by the application to acquire data about a particular analyte.

Solution

A solution to a data acquisition problem is provided by those elements that provide a means to acquire data about an analyte, such as steps of detecting or measuring the concentration of X.

A solution to a data analysis problem is provided by those elements that relate to the analysis of the acquired data for the purpose of providing diagnostic meaning, such as “comparing the expression levels of genes A, B and C to a control standard, wherein a decrease in the levels as compared to the control is indicative of disease Y”.

Purposive construction

The next step is purposive claim construction, including determining whether elements in the claims are essential (provide the solution to the problem) or non-essential. 

Where a data acquisition problem exists, the essential element(s) is the means to acquire data about an analyte. 

Where a data analysis problem is identified, “the essential elements will include steps relating to the mental analysis and/or intellectual significance of the data and will likely not include any steps to acquire the data since the way the data is acquired does not change the nature of the solution”.

Determining whether the claim defines statutory subject-matter

CIPO makes a distinction between “physical”, versus “disembodied”, essential elements in considering whether or not a diagnostic method claim is directed to patentable subject-matter, i.e. within the meaning of “invention” in the Canadian Patent Act.

Where a physical step of data acquisition is identified as an essential element of a claim, the claimed subject-matter will likely be statutory. 

In contrast, where the claim “consist[s] solely of essential elements that are disembodied (e.g., mental process, lacking physicality, no practical application, etc.)” – generally, where the solution is only provided by an element(s) associated with the analysis or significance of the acquired data (e.g. a correlation) – the claimed subject-matter will be identified as non-statutory.