Supreme Court of Canada Voids Viagra Patent

In a unanimous decision released on November 8, 2012, the Supreme Court of Canada (SCC) ruled that Pfizer Canada Inc’s (Pfizer) Canadian Patent No. 2,163,446 (the ‘446 patent) for sildenafil (the active ingredient in VIAGRA) is void because it fails to satisfy the disclosure requirements of the Patent Act. Pfizer had brought an application under the Patented Medicines (Notice of Compliance) Regulations (PM(NOC) Regulations) to prohibit Teva Canada Limited, formerly Novopharm Limited (Teva), from receiving regulatory approval for a generic version of VIAGRA until May 2014 when the ‘446 patent expires. Teva argued that the ‘446 patent was invalid for several reasons, including insufficient disclosure. The Federal Court had previously held that the ‘446 patent was valid and had issued a prohibition order, which was upheld by the Federal Court of Appeal. The SCC reversed the lower courts’ decisions on the basis that the ‘446 patent did not meet the disclosure requirement set out in section 27(3) of the Patent Act, which requires that the specification correctly and fully describe the invention. The ‘446 patent consists of 7 cascading claims which progressively narrowed the class of compounds being claimed. Claim 1 identifies 260 quintillion compounds, whereas Claims 6 and 7 each refer to a single compound, with claim 7 referring to sildenafil. The description of the ‘446 patent discloses that “one of the especially preferred compounds induces penile erection in impotent males.” As affirmed by the SCC, in order to meet the disclosure requirement the patent must enable a skilled person to produce the invention. A skilled reader, said the SCC, could be led to focus on one of the two individually-claimed compounds. However, a “minor research project” would be required to determine whether claim 6 or claim 7 contained the effective compound. Therefore, the patent did not meet the disclosure requirement. The SCC made it clear that sufficiency of disclosure is fundamental to the patent bargain, or quid pro quo, which grants the inventor exclusive rights in a new and useful invention in exchange for the benefit society obtains from the knowledge gained from the disclosure. “[A]s a matter of policy and sound statutory interpretation, patentees cannot be allowed to ’game’ the system” by gaining the benefit of exclusive monopoly rights while withholding disclosure. Given this emphasis placed on proper disclosure, patent drafters and inventors should be careful not to prepare patent applications in an ambiguous manner. The SCC ruled that the ‘446 patent is invalid and void. However, a declaration that the disputed patent is void is not typically available as a remedy in proceedings under the PM(NOC) Regulations where the issue is whether the generic’s allegation of invalidity is justified. As the SCC did not address whether it could make such a declaration in the context of proceedings under the PM(NOC) Regulations, the declaration that the patent is void appears to be an oversight. The SCC docket system indicates that Pfizer will bring a motion to reconsider, likely to request that the SCC find Teva’s allegation of invalidity justified rather than declaring the ‘446 patent void. For the full text of the decision, Teva Canada Ltd v Pfizer Canada Inc, 2012 SCC 60, follow this link: http://tinyurl.com/b44h9wx Summary by: Adam Lis