Court prefers blinded expert in ophthalmic drug patent dispute

In Allergan Inc. v. Apotex Inc, 2016 FC 344, Allergan sought a prohibition order against Apotex in relation to its gatifloxacin ophthalmic product. Justice Zinn held that Allergan failed to demonstrate that Apotex’ allegations of invalidity were unjustified and thus dismissed Allergan’s application.

A critical factor permeating the Court’s decision was the preference for the evidence of Apotex’ expert, Dr. Sheardown. The Supreme Court of Canada has directed that an obviousness assessment should be made “without any knowledge of the alleged invention as claimed.” Justice Zinn noted that Allergan’s expert, Dr. Fix, was not “blinded”: he offered his opinion only after reading the patent and NOA and after having discussed both with Allergan. On the other hand, Dr. Sheardown provided her opinion with no knowledge of the patent at issue or the positions of the parties. In addition, Justice Zinn noted that Dr. Sheardown’s expertise focused on “studying and developing delivery formulations for ophthalmic applications,” which was more specifically directed at the medications at issue.

Apotex alleged invalidity on the basis of obviousness and lack of utility. The Court made no adverse findings against the credibility of Apotex’ expert, but reiterated for almost every issue that it “preferred” the evidence of Dr. Sheardown and thus the Court found in Apotex’ favour.

For obviousness, Dr. Sherdown’s evidence was that a skilled person would have expected that incorporating EDTA would serve to increase gatifloxacin’s corneal permeability and would also have expected that EDTA would prevent precipitation and colorization. Justice Zinn rejected Allergan’s argument that Dr. Sheradown’s “reasonable inference” was not the “ought to work” test required for obviousness, holding:

[39] Dr. Sheardown opines, and I agree, that a POSITA would have a fair and reasonable expectation that combining gatifloxacin with EDTA would produce an effective ophthalmic compound that would have the three advantages set out in the 632 Patent. It would not be a certainty, but it would be higher than a fair expectation of success. In my view, it rises to the level of being more or less self-evident: Eli Lilly Canada Inc v Mylan Pharmaceuticals ULC, 2015 FCA 286.

The Court agreed with Apotex’ obviousness arguments, concluding that “[g]iven the state of the art, a person of ordinary skill had good reason to pursue the known options within his or her technical grasp… [and] the anticipated success was the product, not of innovation but of ordinary skill and common sense.”

The issue of utility was one of sound prediction since Allergan’s witness conceded that utility was not demonstrated. Allergan urged the Court to follow AstraZeneca Canada Inc v Apotex Inc, 2014 FC 638; aff’d 2015 FCA 158, where Justice Rennie held that, except for new use patents, the factual basis for a prediction need not be disclosed in the patent itself. Justice Zinn rejected this argument. Justice Rennie’s decision was based on comments from Teva Canada Ltd v Pfizer Canada Inc, 2012 SCC 60 which he recognized were obiter. The Supreme Court stated that sound prediction was not at issue in that case and “whether there is an ‘enhanced’ or ‘heightened’ disclosure requirement does not arise in this case and need not be addressed.” Justice Zinn pointed to numerous Federal Court of Appeal decisions, as well as the Supreme Court’s decision in Apotex Inc v Wellcome Foundation Ltd, 2002 SCC 77, which held that the patentee may only rely on the facts and line of reasoning disclosed in the patent.

Utility centered on whether one could have soundly predicted that the claimed levels of EDTA would prevent precipitation of gatifloxacin crystals in solution. Dr. Shearbrook argued that there was no basis in the patent from which a prediction could be made that the low concentrations of EDTA claimed would prevent precipitation. The patent only disclosed testing of three formulations. Allergan’s expert asserted that, based on the disclosed tests, the skilled person would know or infer that EDTA was the component impacting on precipitation. However, he did not opine in his affidavit that the skilled person would infer that the result could be obtained at the much lower levels claimed in the patent. The Court thus held that Allergan failed to establish the utility of the patent.

A copy of the judgment can be found here.