Case: Novo Nordisk Canada Inc. v. Cobalt Pharmaceuticals Inc.
Drug: repaglinide ( GLUCONORM®)
Nature of Case: PM(NOC) Regulations: Prohibition proceeding - Section 6
Successful Party: Cobalt Pharmaceuticals Inc.
Date of Decision: August 3, 2010 (Public reasons released on this date)
On July 15, 2010, the Federal Court dismissed an application by Novo Nordisk Canada Inc. and Dr. Karl Thomae GmbH for an order prohibiting the Minister of Health from issuing a notice of compliance to Cobalt Pharmaceuticals Inc. ("Cobalt") in respect of a generic version of repaglinide (GLUCONORM®) until the expiry of Canadian Patent No. 2,111,851 (the "'851 Patent"). The Court held that Cobalt's allegation of obviousness was justified, but that its allegations of anticipation and material misrepresentation pursuant to s. 53 of the Patent Act were not.
The '851 Patent claims one enantiomer (repaglinide) of a previously disclosed racemate that has surprising pharmacokinetic properties and is particularly suitable as a treatment for lowering blood sugar. The racemate was first disclosed in Canadian Patent No. 1,225,398, which claims a class of benzoic acid derivatives that have blood sugar lowering activity, as well as in Canadian Patent No.1,292,000, which claims polymorphs of the racemate and its enantiomers for use for the treatment of diabetes mellitus. Repaglinide (the enantiomer) was not disclosed previously.
In assessing obviousness, Mactavish J. focused on the obvious-to-try test first articulated in the Sanofi decision. Mactavish J. noted that while the Supreme Court in Sanofi found that there was little motivation to separate and test enantiomers as of 1987, "the world had evolved [by 1991] and it was now the state of the art" to do so. Mactavish J. held that although "one could not predict what the pharmacokinetic properties of any given enantiomer would be", it was more or less self-evident that its pharmacokinetic properties "could differ significantly from the racemate and from each other" and therefore "it was important to test them." The Court also accepted that "one could not have predicted that repaglinide would have the three advantageous properties identified in the specification" and that "it might not have been 'very plain' from the prior art what repaglinide's pharmacokinetic properties would be as of [the claim date]." However, Mactavish J. found that the prior art disclosed more than a "mere possibility that testing the enantiomers [of the racemate] for their pharmacokinetic properties was something that might be worth trying." In fact, "it was self-evident that a person skilled in the art would test enantiomers for the pharmacokinetic properties" and that repaglinide's properties would "inevitably have been discovered as a result of this routine testing." On this basis, the Court held that Cobalt's allegation of obviousness was justified.
The Court rejected Cobalt's allegation of anticipation on the basis that repaglinide and its special advantages were not disclosed in the prior art. Mactavish J. also rejected Cobalt's allegation of inherent anticipation. With respect to Cobalt's allegation that the patent application contained material misrepresentations, the Court held that any misstatements were inadvertent and did not engage s. 53 of the Patent Act. Further, Mactavish J. found that "it was incumbent on Cobalt to 'squarely' question the inventors as to whether any omissions in the patent were the product of an intent to mislead." Consequently, Cobalt's allegation of material misrepresentation was not justified and Cobalt's claim for costs was reduced by 25% as a result.
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