• Federal Court Grants Prohibition Order - Invention Not Obvious To Try [EZETROL®(EZETIMIBE)]
  • October 4, 2010 | Author: Jason C. Markwell
  • Law Firm: Norton Rose OR LLP - Toronto Office
  • CASE:
    Merck-Frosst--Schering Pharma GP et.al.  v. Teva Canada Limited et.al (Federal Court)

    ezetimibe (EZETROL®)

    NOC Regulations: Prohibition application - Section 6

    Merck-Frosst-Schering Pharma GP et.al.

    September 17, 2010


    On September 17, 2010, the Federal Court granted an application by Merck-Frosst-Schering Pharma GP and Schering Corporation ("Merck") for an order prohibiting the Minister of Health from issuing a notice of compliance to Teva Canada Limited ("Teva") for a generic version of ezetimibe until after the expiry of Canadian Patent No. 2,172,149 ("149 Patent"). Ezetimibe is a beta-lactam drug that is approved for the treatment of hypercholesterolemia.

    The sole issue in this proceeding was whether the 149 Patent was obvious in light of a prior patent claiming a genus of hypocholesterolemic beta-lactam compounds ("'007 Patent"). The Court described this central issue as "a stark contrast between experts as to whether the '007 Patent made it 'obvious to try' what became the 149 Patent set against the reality of what Merck did to discover ezetimibe."

    Teva's expert set out a "ten step" process which, he opined, a skilled person would have known to follow and which would have led to ezetimibe.  Phelan J. disagreed and held that this process included too many potential missteps to render the claimed invention obvious, easy or self-evident.  Merck synthesized more than 1000 compounds and conducted thousands of time consuming and difficult experiments over the course of several years to arrive at the patented compound.  Phelan J. held that "when working with the prior art, Merck not only did not know the steps to take or the course to develop, it was not even certain of the destination."  Teva's expert benefited from hindsight and engaged in a "reverse engineering" exercise.  The Court noted that a patented invention may be obvious in spite of extensive development work; however, in this case, Teva did not challenge the "efficiency, efficacy or motivation of Merck in the lead up to the discovery" of the ezetimibe.  The Court declined to apply a prior UK decision[1], as the Canadian 'obvious to try' test is different from the U.K. 'worth a try' test.

    The patented invention was not obvious to try.  The Court accepted Merck's evidence and granted a prohibition order.




    [1] [1989] R.P.C. 147 (C.A.)