Alan Macek

[co-author: Pasha Kulinich] In Dusome v. Canada (Attorney General), 2025 FC 1809, the Federal Court reviewed the Commissioner of Patents' decision refusing to grant Canadian Patent Application Number 2,701,028 on the basis that it was a “mere scientific principle or abstract theorem.” This decision has important implications for how CIPO assesses subject‑matter eligibility, particularly for computer‑implemented inventions, business methods, and game‑related claims.

The Canadian Patent Office has a procedure for the “re-examination” of a granted patent. However, this procedure is rarely used in Canada for several reasons. Less than half a dozen re-examinations are filed each year. Anyone, including the owner of the patent may request re-examination on the basis of prior art, namely patents, patent applications and printed publications (see s. 48.1 of the Patent Act).

Claims for infringement of a patent have an unusual place when it comes to limitation periods. A recent decision of the Alberta Court of Appeal has provided some clarity to this issue but there is still uncertainty as to limitation periods for infringement claims. Most provinces have legislation that impose a limitation period on claims.