Tag Archives: Diagnostic Method Claims

The Canadian Patent Office released today practice guidelines regarding the patent-eligibility of medical diagnostic methods and medical methods. The practice guidance are in effect immediately and until further notice, and in place of any contrary guidance presently in the Canadian Manual of Patent Office Practice (MOPOP, the Canadian equivalent to the US MPEP, setting forth examination criteria for patent applications).

Diagnostic Methods

The guidance document indicates that many diagnostic methods can be thought of as comprising two distinct aspects: data acquisition steps and data analysis steps. A claim often contains one or more data acquisition steps, such as a step for determining, measuring, identifying, assaying, etc. which may be implicit or explicit. Diagnostic methods are patentable before the Canadian Patent Office if the claim describing the method satisfies all the requirements of patentability, i.e., novelty, inventive, useful, sufficiently disclosed and unambiguously defined and contains an inventive concept that is statutory.

In order to be patentable, the inventive concept of the diagnostic method claim must provide a solution to a technical problem and either have physical existence or manifest a discernible effect or change. If the claim includes at least on step of physically acquiring data from an analyte (such as a substrate, marker, tissue, body, for example) then the inventive concept is statutory. However, where a known analyte had been previously assessed using the same or similar technique to those in the claim, the inventive concept may therefore be limited to the significance, understanding or interpretation of the acquired data. In these situations, the claim is not statutory because the inventive concept is limited ot the interpretation of the acquired data.

Medical Uses

The guidance also emphasizes that medical methods are not statutory in Canada, while medical use claims are permitted, as long as do not equate to medical or surgical methods and they satisfy all other requirements of patentability.

For patent-eligibilty, the inventive concept of a medical use claim must provide a solution to a technical problem and have either physical evidence or manifest a discernible effect or change. If a claim to a medical use includes a dosage regime or range for the purpose of defining patentability, the inventive concept does not need to include that dosage regime or range if the use itself meets all the requirements for patentability. In contrast, if the inventive concept requires a dosage regime or range, then the inventive concept is considered to be a methods of medical treatment, and therefore not patent-eligibility.

Similarly, where the inventive concept necessary to support patentability only serves to instruct a medical professional “how” or “when” to treat a patient, rather than “what” to use, this may not be patent-eligible as the claim would encompass a method of medical treatment.

Prometheus’ Claims in Canada

As those in the medical industry reconsider US patent strategies in light of Prometheus and the expected US PTO guidance for examiners for medical diagnostic methods, (see our posts of March 20, 2012 and March 25, 2012), the patenting of similar technologies in other jurisdications is of concern as global patenting strategies adopt to the uncertainty of the application of Prometheus by the US PTO.

Canada’s recent guidance appears to follow the US Supreme Court holding that such claims are not patent-eligible for failing to claim a patent-eligible method.

The  “determining” step of the Prometheus claims was stated by the US Supreme Court to add nothing of signficance to the art, and merely told doctors to engage in well-understood, routine, conventional activity previously engaged in by scientists who work in the field. In interpretating the “determining” element under the Canadian guidelines, the inventive concept would be limited to significance, understanding or understanding of the acquired data (as stated by the “wherein” clause of the claim) because the element was previously assessed using the same or equivalent analytical techniques known in the art.

The “wherein” clause would also fail to rescue the claim under the Canadian guidelines as it could be argued to be an expression of the understanding of the discovery of the significance of the acquired data. 

Finally, the “administering” step also was admitted to be known to those in the art and could be precluded from the claim in Canada as being directed to claiming a method of medical treatment.

However, if a diagnostic method is tied to the use of a therapeutic and that use would meets all the other requirements of patentability then the claim is more likely to possess the requisite inventive concept. In addition, if the “determining” step of the claim utilizes analytical techniques unknown to the skilled artisan, the claim is more likely patent-eligible.

A copy of the practice guidelines is available here.