Methods Of Medical Treatment Unpatentable, Supreme Court Affirms

On July 17, 2026, the Supreme Court of Canada (the SCC) issued its decision in Pharmascience Inc. v. Janssen Inc., 2026 SCC 26, dismissing Pharmascience Inc.’s (Pharmascience’s) appeal of a Federal Court of Appeal (FCA) decision upholding the validity of Janssen Inc. and Janssen Pharmaceutica N.V.’s (collectively, Janssen’s) dosing regimen patent.

The dispute arose when Pharmascience attempted to obtain approval to market its generic version of Janssen’s formulation of injectable paliperidone palmitate, which is used to treat schizophrenia and related disorders. Janssen brought an action in the Federal Court alleging that Pharmascience’s generic product would infringe its Canadian Patent No. 2,655,335 (the 335 Patent). In response, Pharmascience argued that (1) its generic product would not infringe the claims of the 335 Patent, and (2) the claims of the 335 Patent were invalid for obviousness and lack of patentable subject matter.

The Federal Court held in favour of Janssen, finding that Pharmascience’s generic product would infringe the 335 Patent, and that the 335 Patent was valid. The FCA upheld the Federal Court’s findings, affirming the validity of the 335 Patent.  Pharmascience appealed to the SCC solely on the issue of whether the claims of the 335 Patent encompassed unpatentable subject matter, namely methods of medical treatment. In response, Janssen argued that the Patent Act no longer excludes methods of medical treatment from patentable subject matter since the repeal of s. 41(1).

In 1974, when the SCC held that methods of medical treatment were not patentable, chemical substances intended for food or medicine were not themselves patentable; they could be protected only by a product by process claim. The SCC relied in part on that restriction in finding that methods of medical treatment were not patentable. The restriction was repealed in 1993, and it has been an open question whether the change that allowed protection of pharmaceuticals themselves meant that methods of medical treatment were now patentable.  

In this case, the SCC reaffirmed that methods of medical treatment, falling under the category of “professional skills”, are not patentable subject matter in Canada.

The SCC then turned to the question of whether drug-dosing regimen patents constitute methods of medical treatment. The Court found that the appropriate question to ask in this situation is whether the subject matter of the patent amounts to professional medical skill and judgment, the answer to which will depend on the nature of the specific claims and the facts of each case.

In this case, though the 355 Patent provided separate dosing regimens for patients with and without impaired kidney function, and gave choices around dosing windows and injection site, the SCC affirmed the lower courts’ findings that these dosing regimens did not amount to professional medical skill and judgement, including quoting the FCA that the different doses “is an objective distinction that does not involve the exercise of a physician’s skill and judgment”. However, the SCC noted that some dosing regimen patents may claim unpatentable subject matter, though that was not the case here.

The Court accordingly dismissed Pharmascience’s appeal.

Summary By: Claire Bettio