Knowledge & News

Diagnostic Methods receive a better prognosis in Canada

12 November 2020

The Backstory

On November 3, 2020, the Canadian Intellectual Property Office (CIPO) released new guidelines and examples for the assessment of patentable subject matter, which take into account the recent decision of the Federal Court in Yves Choueifaty v Attorney General of Canada, 2020 FC 837. The new guidelines represent a major development in the patenting of medical diagnostic methods in Canada, as they make possible the patenting of claims that previously would have been rejected. This is good news, and it quite simply could not have come at a better time, as innovators all around the world rush to answer the urgent calls of health care systems and governments in crisis due to the COVID‑19 pandemic, and as a result, also face the need to protect their IP in key markets like Canada.

Medical diagnostic methods often involve a physical step of measuring an analyte (e.g. a biomarker) and a correlation step. Under the “old” guidelines, CIPO instructed Examiners to discount the physical step recited in a claim if it was already known (i.e. not new and inventive), leaving a bare correlation element that was characterized as being a “disembodied mental conclusion” or “abstract idea” and therefore unpatentable. This is no longer the case.

The new guidelines indicate that a correlation that co-operates with the other elements of the claim becomes part of a combination of elements making up a single “actual invention” that may constitute patentable subject matter if the actual invention either has physical existence or manifests a discernible physical effect or change. Thus, a correlation on its own would generally be considered an abstract or disembodied idea (which is unpatentable), but a claim to a medical diagnostic method that also includes one or more physical steps (such as carrying out a medical test or determining the presence or quantity of the analyte in a sample) may constitute patentable subject matter.

How it works – Do this, not that

In the Examples appended to the guidance, CIPO considers a scenario where a specification describes a method of diagnosing whether a patient is at risk for developing cancer and discloses that a relative increase in X as compared to a non-cancerous reference sample correlates to increased cancer risk. In this hypothetical scenario, CIPO indicates that the following claim would be patentable:

  1. A method of diagnosing whether a human subject is at risk for developing cancer, comprising:
    1. measuring the level of X in a biological sample from the subject; and
    2. comparing said level to the level of a non-cancerous reference sample, wherein an increase in the level of X relative to said reference indicates the subject is at risk for cancer.

However, the Examples go on to say that if the measuring step were replaced with a step of receiving data about the level of the analyte, the resulting claim would not be patentable because it lacks physicality.

The Takeaway

We recommend that you review your patent portfolios to see whether you have any pending applications in Canada that are related to medical diagnostic methods, as it may be possible to recapture claim scope that was lost by making amendments to overcome subject matter objections under the previous guidelines. Such amendments must be made while the application is still pending. For example, this kind of amendment could be made when responding to an Office Action, reviving an abandoned application, or requesting withdrawal of a notice of allowance. Please do not hesitate to contact us if you have any questions or concerns about how to get the best protection for your inventions under the new guidelines.


Jennifer Ledwell

Jennifer Ledwell Managing Associate Ottawa (Canada) Canadian Patent Agent

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