Supreme Court of Canada to Rule on Medical Treatment Patent Validity in Landmark Janssen Case
Key Insights
The Supreme Court of Canada (search) heard arguments in October 2025 regarding the patentability of medical treatment methods in Pharmascience Inc. v Janssen Inc., focusing on Janssen's paliperidone palmitate patent for schizophrenia (search) treatment.
The case centers on whether Janssen's Canadian Patent No. 2,655,335 relating to INVEGA SUSTENNA dosing regimens constitutes an unpatentable method of medical treatment or a patentable medical use.
The Federal Court of Appeal previously ruled that patentability depends on whether the invention requires physician skill and judgment, distinguishing between "how to use" versus "whether to use" the invention.
The Supreme Court of Canada (search) heard arguments on October 9, 2025, in a landmark case that will determine the patentability of medical treatment methods in Canada. The case, Pharmascience Inc. v Janssen Inc. (Supreme Court File No. 41209), focuses on whether Janssen's Canadian Patent No. 2,655,335 relating to paliperidone palmitate (INVEGA SUSTENNA) is invalid for claiming an unpatentable method of medical treatment.
Central Patent Dispute
The patent at issue includes claims featuring a paliperidone palmitate formulation dosing regimen for treatment of schizophrenia (search). This case represents the culmination of over ten years of legal uncertainty since the Federal Court of Appeal flagged the patentability of methods of medical treatment as worthy of full consideration by Canada's highest court.
At the Federal Court level, Janssen's patent was found to be valid and infringed. However, Pharmascience appealed on the sole issue that the claims were invalid as claiming an unpatentable "method of medical treatment." The Federal Court of Appeal dismissed this appeal, establishing a framework that has guided lower courts but left fundamental questions unresolved.
Legal Framework Under Review
The Federal Court of Appeal concluded that determining whether a claim constitutes proper subject matter depends on whether the invention requires the exercise of skill and judgment of a physician. The court rephrased this distinction as one between "how to use the invention" versus "whether or not to use the invention."
Under current Canadian patent law, methods of medical treatment are not considered patentable, whereas claims directed to a medical "use" are patentable. However, significant uncertainty has existed regarding the patentability of medical use claims involving dosage ranges and regimens, precisely the type of claims at issue in the Janssen patent.
Broader Implications for Pharmaceutical Patents
The Supreme Court's decision, expected in 2026, will have far-reaching implications for pharmaceutical patent protection in Canada. The ruling will clarify the boundary between patentable medical uses and unpatentable medical treatment methods, particularly for claims involving specific dosing regimens and treatment protocols.
This distinction is crucial for pharmaceutical companies seeking to protect innovations in drug delivery, dosing schedules, and treatment protocols. The outcome will influence how patent applications are drafted and prosecuted in Canada's life sciences sector.
Regulatory Context
The case comes amid broader developments in Canadian pharmaceutical regulation. In 2025, the Patented Medicines Price Review Board finalized new guidelines that came into effect on January 1, 2026, implementing a two-step review process for patented medicine pricing. Additionally, Health Canada released updated draft guidance for biosimilar submissions, proposing to eliminate the requirement for phase III clinical trials to prove safety and efficacy.
Patent Term Adjustment System
Separately, Canada's new Patent Term Adjustment (PTA) system came into force on January 1, 2025, designed to compensate patentees for unreasonable delays by the Canadian Intellectual Property Office (search) in processing patent applications. The system applies only to patents issued on or after December 2, 2025, with filing dates on or after December 1, 2020. The official fee to apply for PTA is CAD $2,567.50, and requests must be filed within three months of patent issuance.
The Supreme Court has reserved its decision in the Janssen case, with the ruling expected to provide definitive guidance on one of the most contentious issues in Canadian pharmaceutical patent law. The decision will resolve the uncertainty that has persisted for over a decade regarding the patentability of medical use claims involving dosage ranges and treatment regimens.