Teva Canada Ltd. v. Pfizer Canada Inc., 2012 SCC 60

The Supreme Court of Canada has ruled that Pfizer’s patent 2,163,446 (446 Patent), which covers quintillions of compounds for the treatment of erectile dysfunction (ED), is void, clearing the way for Teva’s generic version of Viagra. The Court held that the 446 Patent did not meet the disclosure requirements under s. 27(3) of the Patent Act — the 446 Patent stated that one of nine “especially preferred” compounds was effective in treating ED in patients, but it did not specify which one. The intervenor, the Canadian Generic Pharmaceutical Association, was represented at the Supreme Court of Canada by Heenan Blaikie lawyers Jonathan Stainsby and Andrew Skodyn.

This decision is the most recent statement from the Supreme Court confirming that at its heart, the patent system is a “bargain” — an inventor is granted exclusive rights in a new and useful invention for a limited term in exchange for public disclosure of the invention.   

Claim 1 of the 446 Patent sets out formula (I), which encompasses 260 quintillion possible compounds. Claims 2 to 5 are for successively smaller ranges of compounds. Claims 6 and 7 relate to a single compound each. Specifically, Claim 7 refers to sildenafil, the active compound of Viagra, though the 446 Patent did not identify it as such.

In seeking approval for its generic version of Viagra, Teva alleged that the 446 Patent was invalid for, among other things, failing to disclose the identity of sildenafil as the only compound that had been demonstrated to be effective. Focusing only on Claim 7, the Federal Court found that the patent did properly disclose the invention and prohibited Health Canada from issuing the NOC. The Federal Court of Appeal affirmed this decision. Teva appealed to the Supreme Court of Canada. The main issue on appeal was whether Pfizer had properly disclosed its invention when it applied for the 446 Patent.

Contrary to the view of the Federal Court, the Supreme Court took the position that the courts should not consider the validity of a single claim independent of the rest of the specification – “what the Act requires is that the courts consider the specification as a whole to determine whether the disclosure of the invention is sufficient” (para. 55). Based on the specification as a whole, the Court found that the use of sildenafil and the other disclosed compounds for the treatment of ED as set out in the disclosure of the 446 Patent comprised one inventive concept.

On the facts of the case, however, it was found that the invention was in fact the use of sildenafil for the treatment of ED, but that “there is nothing to support the view that the use of sildenafil for treatment of ED is a separate invention from the use of any of the other claimed compounds for that same purpose” (para. 66). 

Speaking for the Court, Justice LeBel stated: “the invention was the use of sildenafil for the treatment of ED. This had to be disclosed in order to meet the requirements set out in s. 27(3) of the Act” (para. 72). LeBel J. went on to state that: “even if a skilled reader could have narrowed the effective compound down to the ones in Claim 6 and 7, further testing would have been required to determine which of those two compounds was actually effective in treating ED” (para. 74). Accordingly, he concluded (para. 80):

... the public’s right to proper disclosure was denied in this case, since the claims ended with two individually claimed compounds, thereby obscuring the true invention. The disclosure failed to state in clear terms what the invention was. Pfizer gained a benefit from the Act —exclusive monopoly rights — while withholding disclosure in spite of its disclosure obligations under the Act. As a matter of policy and sound statutory interpretation, patentees cannot be allowed to “game” the system in this way. This, in my view, is the key issue in this appeal. It must be resolved against Pfizer.

Having found that the 446 Patent did not comply with s.27(3) of the Act, the Court concluded that the 446 Patent was invalid (para. 84):

Although s.27 does not specify a remedy for insufficient disclosure, the logical consequence of a failure to properly disclose the invention and how it works would be to deem the patent in question invalid. This flows from the quid pro quo principle underpinning the Act. If there is no quid — proper disclosure — then there can be no quo — exclusive monopoly rights.

The Supreme Court of Canada’s decision not only stands to pave the way for generic Viagra in Canada, but also serves as notice that the courts will not tolerate anything less than full and explicit disclosure in the context of a patent application. The Court expressly stated that the so-called “Consolboard questions” (“What is your invention?” and “How does it work?”) are not the only questions to be answered in assessing the sufficiency of a patent’s disclosure. Therefore, in order to avoid having a patent invalidated, applicants will want to ensure that they keep up their end of the bargain, by disclosing sufficient information “to enable a person skilled in the art or the field of the invention to produce it.”