What The Supreme Court Of Canada Was Not Told About Patent Utility

On November 8, 2016 the Supreme Court of Canada ("SCC") heard an appeal by Astrazeneca regarding the validity of a patent covering its NEXIUM product.1 At trial and before the Federal Court of Appeal, Apotex successfully argued that Astrazeneca's patent was invalid for lack of utility on the basis of a failure to demonstrate or soundly predict the promised utility as of the patent's filing date. At issue before the SCC was the legitimacy of the so-called "Promise Doctrine", as well as the proper approach to take in evaluating whether a claim meets the Patent Act's utility requirement.2

The legitimacy of the Promise Doctrine was raised years earlier when the SCC granted leave on this issue in Plavix3, only to have Apotex discontinue its appeal on the day before the hearing. In seeking leave to appeal and in its written materials, Astrazeneca focused on both the legitimacy of the Promise Doctrine and the approach to be taken in considering utility. However, in oral argument, counsel for Astrazeneca's argument focused little on the Promise Doctrine's legitimacy and heavily on the approach to be used in considering utility. Below is commentary on the Promise Doctrine, including its historical basis and its importation into Canadian law without statutory enactment.

What is the Promise Doctrine?

In Canada, the Federal Court and the Federal Court of Appeal have routinely stated that "a scintilla of utility" will suffice to meet the section 2 statutory requirement of "useful".4 Until the jurisprudence changed (around 2005 in the Federal Court5), a claimed invention only needed any utility to be useful and meet the statutory requirement in the Patent Act. However, starting in the mid-2000s the Courts started reading in promised utilities into claims based on statements in the patent disclosure.

For example, in the Accupril case, the Court found that the compound claims 3 and 5 attached to a promise to treat hypertension. These claims did not specify the purpose for which the compounds were to be used.6 For a claim to a compound, the requisite utility had previously been a mere scintilla, but in this case, it was now required that the compound provide treatment of a medical condition because of its activity as described in the disclosure.

Thus a jurisprudential wedge on utility in the Federal Court arose.

The myriad of decisions that followed led to confusion and uncertainty, some cases overlaying one or more statements from patent disclosures into the claims, other cases declining to do so.7 The Federal Court of Appeal attempted to rationalize the law by confirming that a scintilla of utility meets the statutory requirement for utility and finding that any further requirement of utility is only to be found where the Court has found an explicit promise of a specific result in the patent specification.8 Then the Court has required that the patentee show that the promise(s) was/were demonstrated or soundly predicted as of the patent filing date.9 Unfortunately, some Courts have confused some statements of advantages or preferences of a claimed invention with explicit promises.

In the Esomeprazole case, multiple statements or promises were found from the patent specification, and a failure to demonstrate or soundly predict one or more of those promises sufficed to invalidate the patent claims at issue.10

In considering sound prediction, some decisions from lower courts have imposed the requirement that the support for the sound prediction must also be disclosed in the patent11 where it is not part of the skilled person's common general knowledge, even though the SCC has stated that utility is considered separate and apart from the section 27(3) disclosure requirements of the Patent Act in Viagra.12

Thus, the Promise Doctrine created - without any statutory enactment - three additional requirements for "usefulness" in Canadian law as follows:

The tying of statements made in a patent to a "promised utility"; The requirement that the...