Smoothing Out the Patent Prosecution Process for Diagnostic Methods in Canada

August 11, 2021
By Melanie Szweras and Keon Coleman

The Patent Appeal Board (PAB) recently overturned its decision rejecting the patentability of diagnostic methods in both Re Abbott Molecular Inc. (2021 CACP 19) and Re Genentech, Inc. (2021 CACP 20). Abbott Molecular’s and Genentech’s patent applications 2,599,445 (the ‘445 application) and 2,569,520 (the ‘520 application), respectively, were previously rejected for being limited to disembodied mental conclusions, which are not patentable.

Present in the claims of both applications are data acquisition and data analysis steps. In the ‘445 application, the exemplary claim recites that suitability for treatment can be determined by experimentally ascertaining the copy number of both HER-2/neu and TOP2A in a biological sample with chromosomal probes; wherein in an increase in copy number of HER-2/neu but no increase in TOP2A correlates with responsiveness to antibody treatment. In the ‘520 application, the exemplary claim recites that suitability for antibody treatment can be determined by experimentally determining the presence of wild-type KRAS protein or gene, or mutated KRAS protein or gene in a tumor sample. The presence of wild-type KRAS, or absence of mutated KRAS correlates with suitability for treatment. Alternatively, the presence of mutated KRAS correlates with poor prognosis to chemotherapy.

The rejections found in the defective Final Action notices of both the ‘445 and the ‘520 applications were based on a purposive construction recently found to be erroneous by the Federal Court of Canada (read our article here).1 The erroneous purposive construction allowed for parts of the claims to be ignored based on the prior practice by CIPO in construing the claims. In that practice, the Examiner reviewed the application to determine if the invention solved a data acquisition problem or a data analysis problem. For the ‘445 and ‘520 applications, the Examiner considered the problem to be solved a data analysis problem and thus considered the data acquisition elements of the claims to be nonessential to solving the problem. Consequently, the remaining essential elements were found to be directed only toward correlation steps, which were characterized as disembodied mental conclusions, and thus not patentable.

Under the correct approach, Examiners are required to purposively construe claims as set out by the Supreme Court of Canada.2 Further, the CIPO guidance document PN2020-04 makes clear “that all elements set out in a claim are presumed essential, unless it is established otherwise or is contrary to the language used in the claim”. Based on the correct purposive construction, the PAB found on the facts, both the ‘445 and the ‘520 applications comprise physical steps of data acquisition as well as data analysis elements, which cooperate to form a single invention that allows for the identification of suitability and responsiveness to treatment. In particular, the PN2020-04 guidance document states that to be patentable, the combination of elements should cooperate together to manifest a discernable physical effect or change.

These decisions make clear that the PAB is now considering the claims as a whole, and when there is cooperation between the data acquisition and data analysis elements of the claims, diagnostic methods will be held patentable. It is hard to imagine any type of diagnostic claim where the data acquisition and data analysis steps do not cooperate together and therefore, these decisions are a welcome confirmation by the PAB that such claims will now be allowed.

1Yves Choueifaty v Attorney General of Canada, 2020 FC 837.

2Free World Trust v Électro Santé Inc, 2000 SCC 66 and Whirlpool Corp v Camco Inc, 2000 SCC 67.

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