In Eli Lilly Canada Inc. v. Apotex Inc., (2024 FCA 72), the Federal Court of Appeal (“FCA”) considered the threshold for sufficient disclosure of a patent application in reviewing the decision of the Federal Court that found various claims of Canadian Patent No. 2,226,784 to be invalid.

The appeal centered largely on the definition of a “physiologically acceptable salt of tadalafil” and whether the patent provided sufficient disclosure regarding physiologically acceptable salts of tadalafil.

While the FCA confirmed that a patent specification may be sufficient even if some amount of non-inventive trial and error experimentation is required to re-create the invention, the FCA ultimately upheld the decision of the Federal Court citing evidence that the search for a physiologically acceptable salt of tadalafil requires a lot of experimental work and requires a skilled person to exercise some degree of inventiveness.

A copy of the full decision is available here.