In a decision dated May 27, 2016 in respect of Bristol-Myers Squibb’s (“BMS”) REYATAZ® (atazanavir bisulfate),1 Justice Mactavish of the Federal Court prohibited the minister of health from issuing a NOC to Teva in respect of its generic atazanavir bisulfate product until after the expiry of Canadian Patent No. 2,250,840 (“840 Patent”). In particular, the Court disagreed with Teva’s allegations that the 840 Patent (which relates, inter alia, to the compound atazanavir) was invalid on the grounds of anticipation and obviousness.
However, Justice Mactavish dismissed BMS’s application in respect of Canadian Patent 2,317,736 (“736 Patent”), which relates to the bisulfate salt of atazanavir, as the Court found that BMS had failed to prove that Teva’s allegation of obviousness was unjustified.
The 840 Patent
In respect of Teva’s allegation of obviousness of the 840 Patent, the Court first noted that Teva had failed to discharge its evidential burden of proving that certain pieces of prior art were publically available at the relevant date. The Court noted that the generic must adduce “some evidence which, if accepted, is capable of establishing the invalidity of the patent” (at paragraph 56). The Court also reaffirmed that the generic cannot rely on prior art that is not listed in the NOA.
When considering the issue of obviousness in light of the admissible prior art, the Court first sought to identify the inventive concept of the relevant claims. The issue was whether the inventive concept included the advantageous properties of atazanavir (including, for example, its advantageous resistance profile and high selectivity against HIV protease).
Teva, having not made an allegation relating to the “promise of the patent”, argued that the statements of advantageous properties in the disclosure were merely “aspirational” and not part of the inventive concept. However, the Court agreed with BMS that the advantageous properties of atazanavir should be considered to be part of the inventive concept.
When viewing the inventive concept in light of the admissible prior art and without the benefit of hindsight, the Court held that the relevant claims were not obvious. In doing so, the Court rejected Teva’s argument that only a “fair expectation of success” is required to demonstrate obviousness, noting the Federal Court of Appeal’s recent decision to the contrary in Eli Lilly Canada Inc v Mylan Pharmaceuticals ULC, 2015 FCA 286. In coming to its decision, the Court also appeared to put significant emphasis on the inventors’ prolonged and arduous research in developing atazanavir.
The Court also rejected Teva’s allegation of anticipation in respect of the 840 Patent. Teva had argued that atazanavir fell within a genus of compounds disclosed in an earlier patent. The Court first noted that it was not clear that the earlier patent encompassed atazanavir. Second, Justice Mactavish held that, even if it was encompassed, this does not mean that the genus anticipates the species, which is consistent with the Supreme Court’s decision in Apotex Inc v Sanofi-Synthelabo Canada Inc, 2008 SCC 61. In particular, Justice Mactavish held that:
A claim to a specific chemical compound such as atazanavir is not anticipated by a prior art reference that only teaches a broad genus of compounds into which the specific compound in question arguably falls, where the genus patent does not provide directions that would inevitably result in the specific compound in issue. (at paragraph 259)
Finally, the Court noted that the genus patent did not anticipate the claims in question as there was no enablement; inventive steps would be required to discover atazanavir and its advantageous properties.
The 736 Patent
In respect of the 736 Patent, the Court found Teva’s obviousness allegation to be justified. The Court again rejected Teva’s approach to determining the inventive concept (which was to disregard the disclosure), and found the inventive concept to include the advantages set out in the disclosure (e.g., crystallinity, stability, improved bioavailability).
However, the Court found the claimed invention to be obvious, as it would be “obvious to try” to make atazanavir bisulfate, and the techniques used to identify these properties were routine. The Court again appeared to place significant weight on the inventors’ actual course of conduct, finding that the evidence showed that the bisulfate salt was made easily and quickly.
A copy of the decision can be found here.