Medical Treatment vs. Medical Use: The Shifting Ground Of Patentable Subject Matter In Canada

In Canada, methods of medical treatment are not considered to be patentable due to a long-standing, court-created exclusion established under an old compulsory licensing regime (Tennessee Eastman Co. et al. v Commissioner of Patents, (1972), 8 C.P.R. (2d) 202 (S.C.C.)). The exclusion has persisted in Canadian law, despite the regime no longer being in force. Separately, the Supreme Court has considered and upheld medical 'use' claims (Apotex Inc. v. Wellcome Foundation Ltd., (2002), 21 C.P.R. (4th) 499 (S.C.C.)). The tension between these two precedents can be a significant source of confusion for applicants and foreign practitioners with applications in Canada.

More recently, decisions of the Federal Court have expanded the exclusion, striking down 'use' claims in instances when the claimed invention was deemed to inhibit or require the professional skill or judgement of a physician (e.g., Axcan Pharma Inc. v Pharmascience Inc. et al., 2006 FC 527; Janssen Inc. v. Mylan Pharmaceutical ULC et al., 2010 FC 1123; Bayer Inc. v. Cobalt Pharmaceutical et al., 2013 FC 1061). Claims limited by dosage range, for example, have been invalidated on this basis when the Court found that a physician's skill would be required to select an appropriate dose from within the range.

Prospective patentees accordingly face a somewhat paradoxical situation in Canada: broad 'use' claims are generally permissible from the perspective of statutory subject matter, while narrower claims limited in particular ways can be problematic.

Against this backdrop, the Canadian Patent Office issued a Practice Notice to its examiners in 2014 with guidelines on the examination of medical 'use' claims. Under these guidelines, claims limited by 'what' to use were generally permissible, while those limited by features perceived to require 'how' or 'when' determinations were generally impermissible.

The Practice Notice and its attendant examples were revised in March 2015. The reason for the update is a 2014 decision of the Federal Court, which criticized an earlier decision of the Commissioner of Patents for over-reliance on policy considerations (AbbVie Biotechnology Ltd. v. The Attorney General of Canada, 2014 FC 1251 at [120]-[125]). The most notable changes in the new Practice Notice are a softening of its language, and stark reversal of two previous policies concerning new sites of administration and patient populations.

Whereas the previous Notice indicated that a 'use' claim...