Promises That Can Kill: An Update

Promises That Can Kill: An Update

Under the Patent Act, an invention must be useful to be patentable. While in Canada the inventor does not need to describe the utility of the invention in the patent, where the patent makes a promise of utility, utility is measured against that promise. If the inventor does not make an explicit promise of a specific result, the threshold to find utility will be low; a "mere scintilla" of utility will suffice. Under the “promise doctrine”, a patent which would otherwise be valid can be invalid if it promises more than the invention delivers.

As a result, discerning whether the specification has a promise of a specific result can have significant impact on the validity of a patent. The recent Federal Court of Appeal decision of Apotex Inc v Sanofi-Aventis Canada Inc (“Sanofi”), for which the Supreme Court has granted leave to appeal, advocates for a degree of constraint when determining whether a patent contains a promise.

In Sanofi, the Court held that it must look to the patent to determine whether it contains an explicit promise that the invention will achieve a specific result. Since there is no obligation on the part of the inventor to disclose the utility of his invention in the patent, not every patent contains an explicit promise of a specific result.

The idea of a “promise doctrine” is the subject of a NAFTA challenge by Eli Lilly. Central to Lilly’s argument is that two of Lilly’s patents were invalidated on the ground they were not useful, notwithstanding their approval by Health Canada and their commercial success. Lilly alleges that the promise doctrine is inconsistent with NAFTA as it imposes a significantly higher burden on the patentee than the standard of utility mandated by NAFTA.  Specifically, Lilly alleges that Canada’s failure to abide by its NAFTA obligations has resulted in the unlawful expropriation of its patent rights.  Lilly argues that the “promise doctrine” has caused a dramatic and unprecedented shift in Canada’s utility standard and is inconsistent with the utility standard embodied in NAFTA.   Lilly pointed out that one of the patents was challenged and upheld in 18 countries throughout the world, and Canada was the only jurisdiction to invalidate on the basis of inutility.

Canada, in response, has argued that the “promise doctrine” was endorsed by the Supreme Court as early as 1981 in Consolboard v MacMillan, while NAFTA came into force in 1994. There is no requirement to make a promise, but a promise may be made for a variety of reasons, including where a new and non-obvious use of a known compound is the essence of the invention or in selection patents where a sub-species of the genus has a surprising and non-obvious advantage. Canada further notes that NAFTA does not provide direction as to how the core patent concepts of “new”, “inventive”, and “industrial application” are to be interpreted and applied in particular patent cases.

The Sanofi decision appears to have pushed back on certain elements of the “promise doctrine” that Lilly complains of in its NAFTA challenge. Lilly alleges that the Courts read into the patents an “implied promise” that the drugs would work in the longer term based on the chronic nature of the conditions being treated. In Sanofi, the Court of Appeal finds that the Trial Judge erred in finding a promise on the basis of inferences, in the absence of clear and unambiguous language. Sanofi thus draws a distinction between the potential use of an invention and an explicit promise to achieve a specific result, and finds that a goal is not necessarily a promise.

As noted by Canada in its Statement of Defence, domestic patent law continues to evolve, including the promise doctrine.

One possible way forward is to limit the promise doctrine in a manner similar to the Federal Court’s recent treatment of the heightened requirements for a “sound prediction” of utility.  In a July 2014 Apotex v. AstraZeneca (“AstraZeneca”) decision, Justice Rennie concludes that the patentee should only face a higher burden for disclosed utility in “new use for known compound” type patents.  The rational was that, for these “new use” patents, the entire invention resides in the new utility, hence there should be a higher standard for showing utility.

The appeal of Astrazeneca to the Federal Court of Appeal, the Sanofi appeal to the Supreme Court of Canada, and Lilly’s NAFTA challenge will continue the evolution of these doctrines.


David Heller is a Partner at the Toronto office of Ridout & Maybee LLP, where he specializes in the areas of pharmaceuticals, biotechnology, and chemistry. David has been recognized as a leading IP lawyer in the Chambers Global Guide 2014, 2013, and 2012 rankings.