Boehringer v JAMP continued: Federal Court revisits the test for whether a claim element is essential or non-essential.

Boehringer v JAMP, 2024 FC 1198 was an action under the PMNOC Regulations concerning infringement and validity of two patents relating to the nintedanib capsules (which Boehringer markets as OFEV). The Court found one patent (the 083 Patent) valid and infringed but found the other (the 267 Patent) not infringed.

The decision contains an interesting discussion on a number of points. This post focuses on the Court’s discussion on whether claim elements are essential or non-essential.

The 267 Patent related to formulations containing nintedanib and each claimed formulation included particular amounts of the excipient lecithin. Infringement turned on claim construction – namely, whether lecithin (and its amount) was an essential or non-essential claim element.

Claim elements are presumed to be essential and a party alleging otherwise (Boehringer in this case) bears the onus of establishing non-essentiality. In Free World Trust, the Supreme Court of Canada (SCC) set out a two-part test for determining whether a claim element is non-essential:

For an element to be considered non-essential and thus substitutable, it must be shown either (i) that on a purposive construction of the words of the claim it was clearly not intended to be essential, or (ii) that at the date of publication of the patent, the skilled addressees would have appreciated that a particular element could be substituted without affecting the working of the invention

The SCC based this on Improver Corp v Remington, [1990] FSR 181, which discussed a three-part test:

(i) Does the variant have a material effect upon the way the invention works? If yes, the variant is outside the claim. If no: –

(ii) Would this (i.e.: that the variant had no material effect) have been obvious at the date of publication of the patent to a reader skilled in the art? If no, the variant is outside the claim. If yes: –

(iii) Would the reader skilled in the art nevertheless have understood from the language of the claim that the patentee intended that strict compliance with the primary meaning was an essential requirement of the invention? If yes, the variant is outside the claim.

Justice Furlanetto confirmed that, although the SCC test uses the words “either” / “or”, it has been interpreted by the Federal Courts as one that should be read conjunctively in order to be consistent with the Improver questions and the teachings on purposive construction from Free World Trust.

Boehringer argued the Court was not bound by judicial comity and horizontal stare decisis to follow the Federal Court decisions interpreting the test. They relied on two subsequent decisions that, they argued, interpreted the test differently. The Court found those decisions not responsive to the issue. The first (Allergan Inc v Sandoz Canada Inc, 2020 FC 1189) stated that nothing in that decision turned on whether the test was disjunctive or conjunctive. The second (dTechs EPM Ltd v British Columbian Hydro and Power Authority, 2021 FC 190) suggested that the Court had in fact considered both elements of the Free World Trust test.

Justice Furlanetto rejected the argument that determination of the essentiality of claim elements should be conducted devoid of consideration of the patent or of the purpose intended by the inventor as expressed in the language of the claims. Free World Trust indicates that the claim language is an overriding consideration in purposive construction and in the determination of whether elements are essential. “A court must interpret the claims; it cannot redraft them.” Justice Furlanetto found that to find an element not essential if the language of the claims and a reading of the patent indicates otherwise would be “entirely inconsistent” with the overarching themes in Free World Trust.

Turning to the 267 Patent, the Court held it was clear from the claim language that lecithin was intended to be an essential element. Lecithin was a specific component of each of the claimed formulations. Neither the claims nor the disclosure provided other options in place of lecithin. Expert evidence established that lecithin, even in a small amount, had a significant effect on the dissolution of the finished capsules

Boehringer conceded in argument that they were not arguing inessentiality based on first arm of Free World Trust. In fact, Boehringer filed no expert evidence on the determination of essential elements and instead instructed their expert to not consider whether any of the elements were essential or inessential.

Boehringer focused their submissions on the substitutability of lecithin and other surfactants. The Court did not agree that the skilled person would have considered lecithin to be readily substitutable with another surfactant at the publication date of the patent. Given the specificity of lecithin contemplated by the patent, the skilled person  would not have expected that lecithin in the claimed formulations could be substituted with another surfactant without affecting the working of the invention. There was expert evidence that it was not a simple “plug and play” situation where stability and bioavailability could be assumed. There was no evidence of the stability or bioavailability of a formulation with any variant that could allow the Court to conclude that it would perform substantially the same function in substantially the same way to obtain substantially the same result. Conversely, there was evidence that different surfactants worked in different ways and that the skilled person would not even consider all types of lecithin to have the appropriate properties to satisfy the claimed formulation, let alone variations other than lecithin.

Moreover, the Court relied on the patent’s file wrapper. The argument that lecithin was a non-essential element was inconsistent with positions the patentee had taken during prosecution of the 267 Patent. Section 53.1 of the Patent Act allows a “written communication” of the applicant with the patent office to be admitted into evidence to rebut a representation made by a patentee in an action regarding claim construction. In prosecution, Boehringer had argued that claims were not anticipated or obvious because the asserted prior art did not have the composition of the claimed formulation, including the component lecithin. Boehringer had also highlighted the advantages of lecithin to improve dissolution and bioavailability.

Boehringer argued that the correspondence was not admissible because it was not correspondence about construction. The court found that there is no such restriction in relation to section 53.1 and the correspondence was “precisely” what the section contemplated. A fair reading of the correspondence indicated that the representations were made by the patentee to support the view that lecithin was essential to the formulation claimed.

The Court concluded that Boehringer had not met its burden of establishing that lecithin is a non-essential element of the claims. There was no infringement of the 267 Asserted Claims because lecithin was an essential element of each asserted claim of the 267 Patent and there was no lecithin in JAMP Nintedanib.

A copy of the decision may be found here.