For decades, Courts have sought to determine the types of subject matter eligible for patent protection in Canada. On October 9, 2025, the Supreme Court of Canada will hear an appeal from Pharmascience Inc v Janssen Inc, 2024 FCA 23 (FCA Decision), which may prove to be pivotal in the evolution of Canadian patent law concerning the subject matter eligibility.
At the heart of the dispute is a patent concerning a dosing regimen of a pharmaceutical product, which Pharmascience contends is invalid for claiming an unpatentable method of medical treatment. In Janssen Inc v Pharmascience Inc, 2022 FC 1218, the Federal Court upheld the validity of the patent as claiming patentable subject matter. The Federal Court of Appeal (FCA) affirmed on appeal. Pharmascience thereafter sought leave to appeal to the Supreme Court. Several industry groups have been granted intervenor status.
The Legal Landscape: Methods of Medical Treatment and Patentability
Section 2 of the Patent Act defines "invention" as "any new and useful art, process, machine, manufacture or composition of matter, or any new and useful improvement in any art, process, machine, manufacture or composition of matter".
Subsection 27(8) of the Patent Act provides that no patent shall be granted for any “mere scientific principle or abstract theorem”, but the current version of the Patent Act does not explicitly state that methods of medical treatment are unpatentable.
That said, the Supreme Court has previously ruled that claims for methods of medical treatment are non-economic and fall within the realm of professional skills, making them ineligible for patent protection.
In the pharmaceutical context, courts have typically drawn a line between fixed dosages and dosing schedules (patentable) and dosage and dosing schedule ranges (generally unpatentable). The FCA Decision questioned this distinction, noting that it does not necessarily determine whether a drug is a vendible product. Instead, the FCA emphasized that the proper inquiry is whether the use of the invention (i.e., how to use it, not whether to use it) requires the exercise of skill and judgment.
Further Consideration of “Invention” and the role of AI
While the Supreme Court in Pharmascience v Janssen will be considering whether a method of medical treatment is patentable subject matter, the Court may choose to shed additional light on the proper scope of “invention” under Section 2.
In recent years, the Federal Court and FCA have assessed the patentability of computer-implemented inventions in the Choueifaty and Benjamin Moore decisions. Currently, software and computer-implemented inventions are patentable in Canada provided they meet specific criteria, namely distinguishing between unpatentable abstract algorithms and inventions that improve the computer functionality or have the requisite "physicality".
While the guidance seems clear that AI cannot be an inventor in Canada with the Patent Appeal Board in July 2025 finding that an "inventor" is limited to natural persons (2025 CACP 8), this does not mean that AI itself cannot comprise patentable subject matter, be it the input, the tool, its use, or the output, so long as it is not an abstract idea and meets the "physicality" requirement.
Though there remains a challenge for applicants to ensure that proposed claims comply with current patentability requirements for computer-implemented inventions, the FCA in Canada v Benjamin Moore, 2023 FCA 168 noted that "[a]s always, the determination of patentability is a highly fact specific exercise, and it is impossible to attempt to define the full spectrum of particular circumstances that may exist depending on the nature of a particular invention implemented by computer" and "[t]his is especially so, considering that the technology is becoming more and more complex with quantum technology and the advent of artificial intelligence." This FCA decision resulted in Benjamin Moore's patent applications relating to using a computer for colour selection being sent back to the Canadian Intellectual Property Office to be examined on an expedited basis.
Of note, at the end of August 2025, Benjamin Moore's patents regarding colour selection were again rejected as being akin to a "mere scientific principle or abstract theorem" and comprised unpatentable "professional skills” and “fine arts" (2025 CACP 9 and 2025 CACP 10). Although the proposed claims included input (e.g., "receiving user input from a user input device"), tool (e.g., "[a] computer implemented method for selecting colors"), use (e.g., "selecting at least three colors from the color library"), and output (e.g., "displaying on the visual user interface a combined color score"), the claimed computerized methods were "nothing more than a tool [that] simply manipulated information faster than a human could" and "do[ ] not relate to the patentable 'manual or productive arts.'"
A Case with Far-Reaching Implications
For the parties involved, Pharmascience v Janssen is about what constitutes a method of medical treatment. For the broader patent community, it may offer further guidance on patentable subject matter in Canada, including in the professional skills and fine arts context.
Please note that this article is intended for informational purposes and not as a replacement for detailed legal advice. If you need guidance tailored to your specific circumstances, please contact one of the authors to explore how we can help you navigate your legal needs.
Bennett Jones