Teva Canada Ltd v Pfizer Canada Inc

 is a leading Supreme Court of Canada decision on the disclosure requirements for a patent in Canada.
Background.
While testing the compound sildenafil on patients suffering from angina, Pfizer observed that some patients experienced spontaneous erections. Consequently, Pfizer carried out a clinical study to test the effects of sildenafil on patients with erectile dysfunction (ED). The study showed that sildenafil was effective at treating ED. Pfizer then proceeded to obtain Patent 2,163,446 for the use of a range of compounds for the treatment of erectile dysfunction, even though sildenafil was the only compound in the patent that had been shown to be effective in doing so.
The patent contained a number of claims:
Novopharm (later renamed Teva Canada), a generic drug manufacturer, filed an Abbreviated New Drug Submission with Health Canada in December 2006 to allow for the manufacture of a generic version of sildenafil.
Pfizer applied to the Federal Court for an order under the "Patented Medicines (Notice of Compliance) Regulations", prohibiting the Minister of Health from issuing a Notice of Compliance to Novopharm for a generic version of Viagra until the Pfizer patent expired in 2014. In its defence, Novopharm alleged that the patent was invalid for obviousness, lack of utility, and insufficiency of disclosure so that the generic version of Viagra should immediately be allowed on the Canadian market.
Patent specification in Canadian law.
The disclosure requirements for a patent are set out in section 27(3) of the "Patent Act":
The courts below.
Kelen J released his decision in June 2009, finding in favour of Pfizer. In his decision, he drew upon current Canadian patent jurisprudence:
However, he expressed his discomfort about the contemporary practice of drafting patent claims:
Novopharm appealed to the Federal Court of Appeal, which ruled in favour of Pfizer in a unanimous decision by Nadon JA in September 2010, declaring, "... the Judge did not err. The invention herein is found in the compound disclosed in Claim 7, not in the patent as a whole." In doing so, he relied on the Court of Appeal's ruling in a previous case:
Teva appealed the ruling to the Supreme Court of Canada, for which leave to appeal was granted in May 2011.
At the Supreme Court of Canada.
In a unanimous decision written by LeBel J, the appeal was allowed. The Supreme Court rejected the view that each claim in a patent is necessarily a separate invention, and concluded that a patent specification must be read as a whole when identifying the invention in the patent and determining whether the patent satisfies the disclosure requirement. In its original judgment, the Court declared that Pfizer's patent for sildenafil was void, but the Court later changed its decision to say that Teva had established its allegation that the patent was invalid.
Ruling.
In determining whether the disclosure requirements have been met, the first step is to define the nature of the invention in the patent. This must be done in order to comply with section 27(3), which requires that the specification 'correctly and fully describe the invention'.
Lebel J rejected the lower courts' treatment of each claim in a patent as a separate invention. Rather than treating each claim as a separate invention, the specification must be read as a whole to determine the invention. He concluded that if Pfizer's patent is viewed as a whole, there is only one invention: the use of the compounds that are effective at treating ED. He summarized it thus:
Re-hearing and variation.
On November 9, 2012 (the day after the Court released its judgment), Pfizer filed a motion for the Court to re-hear the appeal. In their application, Pfizer alleged that the court accidentally went beyond its jurisdiction by wholly voiding the Viagra patent.
On June 4, 2013, Pfizer's motion was allowed in part, with the Court varying its reasons and its order. Whereas the Court originally had declared the patent “void”, the Court now revised its holding to say that Teva established its allegation, under the statutory provisions in question, that the patent is not valid. Consequently, there was no longer a judicial declaration of voidness but merely an order that Pfizer's application for a "notice of prohibition" against Teva's version of sildenafil (under subsection 55.2(4) of the Patent Act) is dismissed.
Meanwhile, another generic manufacturer brought a separate action to invalidate Pfizer's patent (under section 60 of the Patent Act). On November 20, 2012, the Federal Court held that it was bound by the Supreme Court's decision and declared Pfizer's patent "invalid and void". Subsequently, on January 22, 2014, the Federal Court of Appeal affirmed the Federal Court's decision.
Consequences.
Teva Canada launched Novo-Sildenafil, a generic version of Viagra, on the day the Supreme Court of Canada released its decision.
On August 5, 2014, the Supreme Court of British Columbia certified a class action against Pfizer.
The plaintiff, Britton Low, alleges that Pifzer wrongfully obtained the Viagra patent, which inflated the price of Viagra by delaying the introduction of competing generic versions.