No Quid Means No Quo – Supreme Court of Canada Invalidates Patent


On November 8, 2012, the Supreme Court of Canada (“SCC”) released its decision in Teva Canada Ltd. v. Pfizer Canada Inc., 2012 SCC 60, which focused on the validity of Pfizer’s patent for VIAGRA. In a unanimous decision, the SCC overturned two lower court decisions by holding that Pfizer’s Canadian Patent 2,163,446 (the “‘446 Patent”) was void for failing to satisfy the disclosure requirements provided for in the Patent Act1. The Canadian patent system is based on a quid pro quo bargain: namely, the inventor is granted exclusive rights in a new and useful invention for a 20-year period in exchange for a sufficient disclosure of the invention so that Canadian society can benefit from this knowledge. Put plainly, if an insufficient disclosure is made in the Canadian patent application, the inventor should not receive the patent monopoly.

The ‘446 Patent

Pfizer’s ‘446 Patent issued in Canada on July 7, 1998 and was set to expire on May 13, 2014. The ‘446 Patent describes a class of compounds for treating erectile dysfunction (“ED”), including a particular compound, sildenafil citrate, which is the active ingredient in VIAGRA. As noted by the SCC, Pfizer had conducted tests at the time of the patent application that indicated that sildenafil was effective in treating ED, but neither the patent disclosure nor the patent claims specified that sildenafil was the compound that worked.

Federal Court Decision2

Novopharm Limited, now Teva Canada Ltd. (“Teva”), applied for a Notice of Compliance in order to produce a generic version of Pfizer’s VIAGRA. In doing so, Teva alleged that the ‘446 Patent was invalid for a number of reasons including insufficient disclosure. In considering this specific issue, the Federal Court noted that the ‘446 Patent identified 9 compounds that were in an “especially preferred individual compound list”, which included sildenafil. The ‘446 Patent stated that “patient studies conducted … have confirmed that one of the especially preferred compounds induces penile erection in impotent males.” This factual determination, along with expert evidence which suggested that a skilled person in the art would be able to determine which compound was the active ingredient based on the fact that only 2 of the 9 compounds were claimed in the ‘446 Patent, assisted the Court in concluding that there had been a sufficient disclosure such that the ‘446 Patent was valid. The Court noted in obiter its concern with the “hide and seek” approach taken in preparing the ‘446 Patent; notably the Court was concerned about the fact that the patent reader was expected to look for the “needle in the haystack” – the needle being the sildenafil compound from a haystack of some 260 quintillion compounds.

Federal Court of Appeal Decision3

On appeal, the Federal Court of Appeal (“FCA”) unanimously upheld the Federal Court’s finding that the ‘446 Patent was valid. The Court approached the disclosure requirement issue by considering two classic4 questions that need to be met to satisfy the disclosure requirement, namely: “What is your invention?” and “How does it work?” The FCA answered the first question by confirming that the invention was “the use of sildenafil … for the treatment of [ED] ….” The Court answered the second question by holding that the “rest of the patent [‘446 Patent] … describes the mechanism of action.” The FCA dismissed Teva’s appeal.

Supreme Court of Canada Decision

On appeal to the SCC, the Court re-confirmed that sufficiency of disclosure in a patent application lies at the very heart of the Canadian patent system. The Court relied on its own statements made in 2002:

A patent, as has been said many times, is not intended as an accolade or civic award for ingenuity. It is a method by which inventive solutions to practical problems are coaxed into the public domain by the promise of a limited monopoly for a limited time. Disclosure is the quid pro quo for valuable proprietary rights to exclusivity which are entirely the statutory creature of the Patent Act.5

The SCC concluded that adequate disclosure is a precondition for the granting of a patent. The SCC ultimately considered the question “what is the invention?” and noted that the invention was not sildenafil (which was already a known cardiovascular drug) but rather the new and non-obvious use of sildenafil to treat ED. While the Court noted that the ‘446 Patent contained the statement that “one of the especially preferred compounds induces penile erection in impotent males”, the ‘446 Patent does not indicate that sildenafil is the effective compound. The SCC went on to state that a person skilled in the art would not have been able to determine that sildenafil was the active compound without conducting further research, which is contrary to the quid pro quo bargain. The Court stated (at para. 84), “If there is no quid – proper disclosure – then there can be no quo – exclusive monopoly rights”. Ultimately, the Court held that Pfizer had chosen a method of patent drafting that had failed to clearly set out what the invention was and, in doing so, the ‘446 Patent was rendered void for insufficient disclosure.

Reconsideration by the Supreme Court of Canada and Further Litigation

In a situation seldom, if ever, seen in intellectual property disputes, the SCC has been asked by Pfizer to reconsider the remedy rendered in the November 8, 2012 decision. As this dispute was initiated as a “Notice of Compliance” proceeding, Pfizer is arguing that the SCC does not have the jurisdiction to invalidate a patent under this legislative scheme. As of press time, the SCC has yet to render their position on Pfizer’s request for reconsideration of the remedy. In a related matter, the Federal Court has ruled that Apotex Inc. can proceed with an impeachment action of the ‘446 Patent (2012 FC 1339).

Conclusion and Practice Points

This decision highlights the importance of adequately disclosing the invention in a Canadian patent application. Indeed, a cornerstone of Canada’s quid pro quo patent system is that full disclosure is required in order for a patent monopoly to be granted; as shown in this decision, failure to adequately disclose the invention can result in an invalid patent. Further, the loss of enforceability of Pfizer’s patent rights by way of this decision highlights the importance of maintaining overlapping forms of intellectual property protection. As an example, Pfizer’s well-established trade-mark registration for VIAGRA now has the potential to play a more significant role in protecting Pfizer’s significant market position by attempting to curtail how generic pharmaceutical companies market their generic equivalents to VIAGRA.


  1. R.S.C. 1985, c. P-4, s. 27(3).
  2. Pfizer Canada Inc. v. Novopharm Limited, 2009 FC 638.
  3. Novopharm Limited v. Pfizer Canada Inc., 2010 FCA 242.
  4. Consolboard Inc. v. MacMillan Bloedel (Sask.) Ltd., [1981] 1 S.C.R. 504.
  5. Apotex Inc. v. Wellcome Foundation Ltd., [2002] 4 S.C.R. 153 at para. 37.