The Supreme Court of Canada Rejects the “Promise of the Patent” Doctrine, Clarifying Utility Requirements in Canadian Patent Law

The Supreme Court of Canada Rejects the “Promise of the Patent” Doctrine, Clarifying Utility Requirements in Canadian Patent Law

In its decision dated June 30, 2017, the Supreme Court of Canada (SCC), allowed the appeal in AstraZeneca Canada Inc. vs. Apotex Inc. from the earlier decision of the Federal Court of Appeal, where AstraZeneca’s Patent No. 2,139,653 covering its blockbuster drug NEXIUM® (esomeprazole) was invalidated for failing to fulfill its inferred “promise” to provide “improved pharmacokinetic and metabolic properties which would give an improved therapeutic profile such as a lower degree of interindividual variation.”

The promise doctrine had developed at the Federal Court level over the past few decades and had increasingly become a weapon of choice for generic pharmaceutical companies in efforts to impeach valuable pharmaceutical patents, thereby allowing generic pharmaceutical products to enter the market at an earlier stage. As one indication of the contentiousness of the promise doctrine, the invalidation of two pharmaceutical patents covering its products STRATTERA® and ZYPREXA® prompted Eli Lilly and Company to initiate an ultimately unsuccessful $500 million claim against the Government of Canada with an allegation that Canada’s patent laws violate intellectual property standards set under NAFTA and discriminate against pharmaceuticals as a field of technology.

In the present decision, the SCC was clear in its rejection of the promise doctrine, indicating that it is not the correct method of determining whether the utility requirement under Section 2 of the Patent Act is met. The Court stated:

“The Promise Doctrine is incongruent with both the words and the scheme of the Patent Act. First, it conflates ss. 2 and 27(3), by requiring that to satisfy the utility requirement in s. 2, any use disclosed in accordance with s. 27(3) must be demonstrated or soundly predicted at the time of filing. If that is not done successfully, the entire patent is invalid, as the pre-condition for patentability — an invention under the s. 2 of the Act — has not been fulfilled. Second, to require all multiple uses be met for the patent’s validity to be upheld, runs counter to the words of the Act and has the potential for unfair consequences.”

The SCC clarified that a proper analysis to determine if a patent discloses an invention with sufficient utility, the courts should: (i) identify the subject matter of the claimed invention and then (ii) determine if that subject matter is useful – i.e. is it capable of a practical purpose? Importantly, the SCC pointed out that the Patent Act does not prescribe the degree or quantum of usefulness required, or that every potential use be realized – a scintilla of utility will do.

Using this approach, the SCC found that the claimed subject matter is useful as a proton pump inhibitor and thus AstraZeneca’s Canadian Patent No. 2,139,653 was found to be valid.

A likely outcome of this SCC decision is that future efforts to impeach Canadian patents on the basis of lack of sufficient utility must be based on factors other than allegations that at least one promise of utility has not been met.

For more information, please contact Mark Roach at