Canada Ltd. v. Pfizer Canada Inc.

Drug: VIAGRA®

The Supreme Court issued its decision today in the much-anticipated patent case involving VIAGRA sildenafil. The Court allowed the appeal, finding the allegations of invalidity to be justified. The decisions of the Trial Division and the Federal Court of Appeal prohibited the Minister of Health from issuing a Notice of Compliance. Our summary of the decision of the Federal Court of Appeal can be found here.

The main issue in this case was “whether Pfizer failed to properly disclose its invention when it obtained the patent for Viagra” pursuant to s. 27(3) of the Patent Act. The Court considered the concept of the patent bargain and held that sufficiency lies at the very heart of the system. The Court considered the traditional questions for sufficiency: “What is your invention?” and “How does it work?” and held that these questions are relevant. However, the description must also enable a person skilled in the art to produce the invention using only the instructions in the disclosure. “The nature of the invention must be disclosed, and the entire specification, including the claims, must be considered in determining the nature of the invention and whether disclosure was sufficient.”

In this case, the Court held that the invention was: the use of sildenafil to treat erectile dysfunction (ED). The disclosure was held not to enable the public to make the invention, as it indicated that one of the compounds had been tested and is effective, but never identified which compound. This led to the public having to complete a research project in order to determine which compound was actually effective to treat ED. Thus, the patent disclosure was not sufficient.

The Court held that s. 58 of the Patent Act and the principle that valid claims survive in the face of invalid claims, is not engaged until it is determined whether the disclosure requirements have been complied with.

The Court also considered the line of cases dealing with multiple inventions in a patent with multiple claims. The Court held that it is possible for each claim in a patent to disclose a separate invention. However, each patent must be considered on a case-by-case basis. The specification should be examined to determine whether the compounds claimed form a single inventive concept.

In addition to sufficiency, the Court considered and dismissed Teva’s arguments that the patent should be invalid for inutility. The Court held that “all that is required to meet the utility requirement in s. 2 is that the invention described in the patent do what the patent says it will do”. As of the priority date, utility must be demonstrated or soundly predicted. But, there is no separate requirement for the disclosure of utility. The Court held that s. 27(3) does not contain any requirement to disclose the utility of the invention. In this case, utility was demonstrated. The Court also held that since sound prediction is not an issue, the question of whether there is an enhanced disclosure requirement with respect to sound prediction need not be addressed.