The Supreme Court of Canada has granted Teva Canada Limited leave to appeal the Federal Court of Appeal's dismissal of Teva's appeal from an order of prohibition regarding sildenafil (Pfizer's VIAGRA®). A hearing is expected later in 2011.
The Supreme Court of Canada will address the issue of whether a patentee is required to establish utility on the basis of sound prediction if the patent states, and there is evidence to support, that the invention has been demonstrated to be useful as of the Canadian filing date.
In 1998 Pfizer Canada Inc was granted Canadian Patent 2,163,446 ('446 Patent), which claimed the use of a compound of formula (I) or a salt thereof as a medicament for the treatment of erectile dysfunction. The effective compound, sildenafil, was claimed in claim 7 of the '446 Patent; however, neither the disclosure nor the claims disclosed that:
- the effective compound was sildenafil;
- the effective compound was claimed in claim 7; or
- the remaining compounds in the patent had not been found to treat erectile dysfunction.
Novopharm Limited (now Teva Canada Limited) applied for a notice of compliance to produce a generic version of VIAGRA®, alleging that the '446 Patent was invalid for obviousness, lack of utility and insufficient disclosure. Pfizer brought an application under the Patented Medicines (Notice of Compliance) Regulations prohibiting the minister from issuing a notice of compliance to Novopharm for a generic version of sildenafil citrate.
In a 2009 Federal Court decision Justice Kelen granted Pfizer's application to prohibit the minister from issuing a notice of compliance to Novopharm for sildenafil (Pfizer's VIAGRA®).
The Federal Court found that Novopharm's invalidity allegation on the grounds of obviousness, utility and insufficiency was not justified. In relation to utility, while Novopharm had argued that demonstration of utility must be in the patent specification, the Federal Court found that it is sufficient for the patent to state that the invention has been demonstrated to be useful and that the patentee can show evidence of demonstrated utility if the validity is challenged. As the Federal Court found that the patent referred to a study, and that study (provided in evidence) established demonstrated utility of the invention, Pfizer was not required to establish utility on the basis of sound prediction. Novopharm appealed to the Federal Court of Appeal.
In its 2010 decision the Federal Court of Appeal upheld Kelen's decision, finding that he was correct to limit the invention to that described in claim 7, as claim 7 represents a compound (sildenafil) within a class of compounds (those given by formula I) used to treat erectile dysfunction and, accordingly, constitutes a separate invention.
The Federal Court of Appeal went on to hold that as the relevant invention was the compound found in claim 7, the disclosure was sufficient. Specifically, the Federal Court of Appeal agreed with Pfizer's submission and with the judge's finding that there is no requirement for a patent to demonstrate utility in the patent disclosure, as the requirements for demonstrated utility can be provided in evidence during invalidity proceedings as opposed to in the patent itself. Thus, so long as the disclosure makes reference to a study (in this case, Study 350) demonstrating utility, there appears to be no other requirements to fulfil Section 2 of the Patent Act. Finally, the Federal Court of Appeal held that Kelen made no palpable and overriding error in determining that Study 350 disclosed utility.
On November 23 2010 Teva applied for leave to appeal to the Supreme Court of Canada and leave was granted on May 5 2011.
The issues before the Supreme Court of Canada include whether:
- guidance is needed on the law of sufficiency of disclosure;
- an allegation of insufficiency is at the 'heart of the patent system' or a 'technical attack';
- the Federal Court of Appeal has confused the Consolboard questions;
- the Federal Court of Appeal condones the imposition of a research project;
- the Federal Court of Appeal's 'claim-based' approach rewrites the law of sufficiency of disclosure;
- the Federal Court of Appeal confuses disclosure of invention with 'best mode'; and
- the Federal Court of Appeal imposes a crippling 'wait and see' regime on generic manufacturers.
For further information on this topic please contact Jayda A Sutton at Smart & Biggar/Fetherstonhaugh by telephone (+1 416 593 5514), fax (+1 416 591 1690) or email ([email protected]).