Claim construction
Anticipation, obviousness and insufficiency

On 28 July 2021, the Federal Court of Appeal dismissed Seedlings' appeal from the Federal Court decision of Justice Grammond,(1) which concluded that certain claims of Seedlings' LifeCard patent, Patent No. 2,486,935 (the 935 Patent), were invalid and not infringed by Pfizer's next-generation EpiPen.(2) The 935 patent relates to an auto-injection device, primarily used for the administration of epinephrine in treating symptoms of anaphylaxis.

Claim construction

Seedlings took issue with the Federal Court's construction of several terms in the relevant claims. The Federal Court of Appeal found no reviewable error. It commented that it is not an error to apply the principle of claim differentiation to compare similar clauses in two claims (such as "coupled to" and "operatively associated with"), even if those two claims have other differences.


The Federal Court held that all relevant claims of the 935 patent were invalid for overbreadth because they omitted essential elements of the invention that were described in the patent disclosure. On appeal, Seedlings argued that:

  • overbreadth lacks statutory basis and is not a proper ground of invalidity; and
  • even if overbreadth were a proper ground of invalidity, the trial judge had erred in its application to the case.

The Federal Court of Appeal rejected both arguments.

The Federal Court of Appeal affirmed that overbreadth is supported by the combination of subsections 27(3) and 27(4) of the Patent Act and, therefore, remains a proper ground of invalidity. While overbreadth can overlap with other grounds of invalidity, it is a distinct ground that must be considered separately.

Seedlings contended that an element described in the patent disclosure but not claimed cannot be considered an essential element that goes to the core of the invention and, therefore, should not be considered when assessing overbreadth. The Federal Court of Appeal disagreed, stating that "determining whether a feature is essential is a distinct exercise for the purpose of overbreadth than for the purpose of claim construction". The Federal Court of Appeal clarified that the test for assessing essentiality for the purpose of overbreadth is whether the element is "so key to the invention described in the disclosure that a claim that omits it encompasses embodiments that were not contemplated in the disclosure".

Finally, the Federal Court of Appeal found that the trial judge, despite having erred in some aspects of the law on overbreadth, had applied the correct legal principles and had made no palpable or overriding error.

Anticipation, obviousness and insufficiency

The Federal Court also held that some claims were anticipated and obvious in view of earlier auto-injector patents. Seedlings argued that the trial judge had:

  • misunderstood the doctrine of approbation and reprobation (ie, accepting Pfizer's position that a prior patent did not anticipate its next generation EpiPen patent but anticipated Seedlings' patent); and
  • engaged in a tortured reading of the prior art (ie, finding that a prior patent taught a needle shield with three positions rather than only two positions).

The Federal Court of Appeal agreed with the trial judge that the doctrine of approbation and reprobation did not apply to this case and found no reviewable error in the trial judge's analysis.

While Pfizer's allegation of insufficiency was dismissed at trial, the Federal Court of Appeal found that all relevant claims of the 935 patent were also insufficient based on the trial judge's finding that a skilled person would not know how to make a device without certain elements which were described in the disclosure but which did not appear in the claims.


Although the issues on remedies were moot, the Federal Court of Appeal disagreed with the Federal Court's ruling that a patentee which makes profits by licensing its patent should not be entitled to elect an accounting of profits. The Federal Court of Appeal was concerned that such a broad principle could have the potential effect of forcing specialist inventors to choose between business efficiency by selling licences to their patents and retaining their right to elect infringement remedies. It further noted that the purpose of an accounting of profits is to deter wrongful conduct rather than to compensate the patentee for its losses.

For further information on this topic please contact Jie Fei (Christina) Pan at Smart & Biggar by telephone (+1 416 593 5514) or email ([email protected]). The Smart & Biggar website can be accessed at


(1) 2020 Federal Court 1, previously reported.

(2) Seedlings Life Science Ventures, LLC v Pfizer Canada ULC, 2021 FCA 154.