In one of its first patent decisions of 2021, the Federal Court tackled arguments regarding the relevant date for insufficiency allegations and the level of disclosure required for demonstrated utility. The Court resolved these and other issues in the patentees' favour, granting declarations of infringement against two proposed apixaban generics.
ELIQUISTM (an blood thinner) is marketed in Canada by Bristol-Myers Squibb Canada Co. Pharmascience Inc. and Sandoz Canada Inc. (the Defendants) sought approval to market generic versions of ELIQUISTM in Canada.
The Court's decision concerned the claims of two patents asserted against each of the Defendants in infringement actions under the Patented Medicines (Notice of Compliance) Regulations (Regulations):
- Canadian Patent No. 2,461,202 (the 202 Patent), which was asserted by Bristol-Myers Squibb Canada Co. and Bristol-Myers Squibb Holdings Ireland Unlimited Company (collectively, BMS). The 202 Patent claims the active ingredient apixaban and its use for the treatment and prevention of thromboembolic disorders (blood clots).
- Canadian Patent No. 2,791,171 (the 171 Patent), which was asserted by BMS and Pfizer Inc. (collectively, BMS & Pfizer). The 171 Patent claims tablet formulations of apixaban.
The Defendants' only non-infringement allegation was that the asserted claims of each of the patents were invalid.
The 202 Patent: compound and use claims valid and infringed
Construction. The sole issue with respect to construction of the asserted claims of the 202 Patent was whether “treatment” meant that apixaban must treat both humans and non-human mammals. Having regard to the definition in the specification, the Court rejected that proposition and agreed with BMS that “treatment is directed to ‘mammals' – and any mammal will do.”
Insufficiency of disclosure. With respect to insufficiency, the main issues concerned the mechanics of the legal test.
First, the Court considered whether insufficiency is directed to the application (as published) or the patent (as issued). At the time it was published, the claims in the 202 Patent application included a large number of compounds. The claims were later amended and, when issued, were specific to apixaban. The Defendants argued that the disclosure did not support the broader scope of compounds in the published application. The Court rejected this argument, holding that while the relevant date is the publication of the application, the document to be assessed as of that date is the patent as issued.
The Defendants also argued that the 202 Patent was insufficient for failing to disclose data regarding the activity of and certain risks associated with apixaban. The Court rejected this argument on the basis that, for the purpose of sufficient disclosure, the patentee is not required to include data to substantiate the invention.
Last, the Court rejected an argument that the patent was insufficient for providing “false dosing information in relation to humans”. The Court held that the relevant passage would have been understood to be general guidance only, and that it was not specific to humans.
Inutility. The Court rejected the Defendants' position that, in a case of demonstrated utility, the patent was required to include a reference to the study demonstrating that utility. The Court also rejected the argument that utility was not demonstrated by an animal study on the bases that the animals were healthy and humans had not been tested. The Court found that the animals were not healthy and, since the claims were directed to mammals generally, there was no requirement to demonstrate effectiveness in humans.
Genus patent issues. The remaining invalidity allegations related to an earlier genus patent: Canadian Patent No. 2,349,330 (the 330 Patent). The Court accepted expert evidence that the skilled person would have understood the 330 Patent to claim an enormous number of compounds (including apixaban) that had the “potential” to treat and prevent thromboembolic disorders.
- Anticipation. The Court held that the genus patent did not anticipate the selection patent's claims. The skilled person reading the 330 Patent would not have been able to “identify apixaban among the universe of compounds it describes, or make the invention of the 220 Patent without extensive and time-consuming work”.
- Obviousness & obviousness-type double-patenting. The Court concluded that the use of apixaban to treat and prevent thromboembolic disorders was not obvious from the 330 Patent and that there was no double-patenting. The Court accepted evidence that to arrive at the invention, “one would have to do what BMS did to find apixaban: namely, engage in complex, time-consuming, unpredictable research.”
- Selection patent issues. Lastly, the Court rejected an argument that the 202 Patent was invalid for “insufficiency and utility as a selection patent” over the 330 Patent. This argument was based on the long-standing three-part test for selection patents. The Court explained that this test determined whether a patent was a selection patent—but not whether it is valid as a selection patent. The Court also found that, even if the 202 Patent were required to meet this test for validity, it did so on the facts.
The 171 Patent: formulation claims valid and infringed
Obviousness. With respect to obviousness, the main issue concerned the dissolution rate and particle size thresholds set out in the claims. In construing and determining the inventive concept of the claims, the Court held that “a formulation patent may not disclose the inventive concept without recourse to the specification.” The Court rejected the Defendant's position regarding the claims on the basis that it ignored the purpose of the thresholds, which would ensure that the tablets provide consistent, solution-like exposures.
The Court held that the subject-matter of the claims was not obvious. The Court found that the dissolution rate threshold was not arbitrary and that the particle size threshold resulted from the discovery of the unobvious problem that “a large particle size of apixaban can adversely affect in vivo exposure”.
Insufficiency & overbreadth. The Court held that the 171 Patent was neither insufficient nor overbroad. The skilled person could have measured the dissolution rate or particle size of the claimed formulations through routine trial and experimentation and the claims were “proper functional claims”.
Ambiguity. The Court held that the 171 Patent was not ambiguous for failing to describe the dispersion method to be used to measure particle size by light scattering. The patent disclosed the method that was used and the skilled person, working the invention, would have done the same.
Inutility. The Court dismissed the Defendants' inutility allegations on the facts, which related to the interpretation of certain data tables in the patent.
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