• Federal Court of Appeal Holds Utility Of A Patent Need Not Be Demonstrated In The Patent Itself [VIAGRA® (sildenafil)]
  • October 11, 2010 | Author: Jason C. Markwell
  • Law Firm: Norton Rose OR LLP - Toronto Office
  • CASE:
    Pfizer Canada Inc. et. al. v. Novopharm Limited

    DRUG:
    sildenafil (VIAGRA®)

    NATURE OF CASE:
    PM(NOC) Regulations: Prohibition application - s. 6

    SUCCESSFUL PARTY:
    Pfizer Canada Inc. et al.

    DATE OF DECISION:
    September 24, 2010

    SUMMARY:

    On September 24, 2010, the Federal Court Appeal dismissed Novopharm's appeal from a Federal Court decision under the Patented Medicines (Notice of Compliance) Regulations.  Justice Kelen had granted to Pfizer Canada Inc. et al. ("Pfizer") a prohibition order preventing the Minister from issuing an NOC to Novopharm Limited ("Novopharm) for a generic version of sildenafil tablets (VIAGRA®) until the expiry of Canadian Patent No. 2,163,446 (the "'446 Patent).

    Utility
    Novopharm argued that Kelen J. erred in finding that the utility of the invention did not have to be demonstrated in the patent itself.   Novopharm also alleged Kelen J. erred in finding that a particular study (the "350 Study") demonstrated the utility of sildenafil for treating ED.  The FCA dismissed both arguments.  Specifically, the FCA held that there is "no requirement for a patent to demonstrate utility in the patent disclosure, so long as the trier of  finds it to be proven upon legal challenge."  Justice Nadon, writing for the Court, went on to state "[t]he requirements for demonstrated utility can be provided in evidence during invalidity proceedings as opposed to in the patent itself.  So long as the disclosure makes reference to a study demonstrating utility, there do not appear to be any other required to fulfill section 2 [of the Patent Act]."

    The FCA also held that Kelen J. made no reviewable error in finding that the 350 Study disclosed utility.  Nadon J. found "although the Judge may have misapplied the 'mere scintilla' test because in the present matter, there had been a specific promise that sildenafil would work to treat ED, his error is, in the end, inconsequential.  The Judge found that the Study 350 revealed a 'significant' improvement in treating ED.  Furthermore, he correctly stated that the test for utility in this case was whether the invention did what it promised, and that he level of proof need not reach the level required by clinical testing."

    Sufficiency
    Novopharm argued that Pfizer failed to disclose its invention by "concealing" which compound in the '446 Patent was sildenafil.   The FCA rejected this argument, holding that since "Claim 7 clearly states the formula for sildenafil" it is accordingly "clearly described."  The FCA also rejected Novopharm's arguments that Pfizer failed to describe the 'best mode' of the invention.  Citing Justice Snider's decision in Sanofi Aventis Canada Inc. v. Apotex Inc., 2009 FC 676,  the FCA noted that "where Parliament had chosen to include a 'best mode' obligation in respect to machine patents only, the courts must respect that choice.  Accordingly, reading such a requirement into non-machine patents would be contrary to the principles of statutory interpretation." 

    The FCA reiterated that a patent disclosure must answer the following questions:  "what is your invention?" and "how does it work?".  The Court found the disclosure in the '446 Patent to be sufficient, as the use of sildenafil to treat ED was claimed and its mechanism of action was described.