The Federal Court of Appeal (FCA) has held that the “inventive concept” can go beyond the essential elements of the claim and may include advantageous properties stated in the patent’s description. The FCA confirmed that the inventive concept is the end-point in the obviousness analysis: for a claimed invention to be obvious, the gap between the inventive concept and the state of the art must have been obvious to the notional uninventive person of skill in the art.


The patent at issue was Canadian Patent No 2,527,646 (the 646 Patent), which claims the chemical compound lisdexamfetamine (LDX) used to treat attention deficit and hyperactivity disorder (ADHD). As we previously reported, the Federal Court (FC) found the 646 Patent valid in prohibition proceedings, dismissed Apotex’s impeachment action, and issued a prohibition order: Apotex Inc v Shire LLC, 2018 FC 637.

Apotex appealed, asserting that the 646 Patent was obvious and anticipated. The FCA dismissed Apotex’s appeal.

The asserted claims were not obvious

The inventive concept. The FC found that the 646 Patent had a single, overarching inventive concept and relied on the 646 Patent’s description in construing that inventive concept. Apotex argued that instead, each claim had its own inventive concept that was to be identified based on the “subject matter of the claim” alone.

In rejecting Apotex’s arguments, the FCA provided guidance on determining the inventive concept:

  • Construe unless agreed to: The inventive concept needs to be construed unless the parties agree on what it is. This is to be done separately from—and after—claims construction.
  • Recourse to the description: The inventive concept of a claim is not materially different from the solution taught by the patent. Further, it is not necessarily limited to the claim’s essential elements. Where the inventive concept cannot be readily discerned from the construed claims, recourse to the patent’s description is appropriate, so long as the inventive concept is not broader or narrower than the text of the claim will allow.
  • Overarching and individual inventive concepts: Typically, every claim in a patent will be connected by a single, overarching inventive concept. Different individual claims can, and generally will, have different inventive concepts—each of them a variation or facet of the overarching concept. While obviousness is a claim-by-claim analysis, a court will not need to explicitly consider each individual claim if the overarching inventive concept is non-obvious.
  • Avoid redundancy: When construing the inventive concept of individual claims, redundancy between different claims should be avoided. Redundancy is permissible where the claims are, in effect, duplicated.

In applying these principles, the FCA found that the inventive concept of the chemical compound claims was not clear from their essential elements. Therefore, it had been appropriate for the FC to consider the description of the patent. The description supported the FC’s overarching inventive concept: “a sustained release formulation of a therapeutically useful dose of amphetamine that is resistant to abuse”. These beneficial properties of LDX were the solution taught by the patent. Therefore, the overarching inventive concept applied to the chemical compound claims, even though the beneficial properties (e.g., sustained release) were not expressly recited in those claims.

There was no impermissible redundancy. Although certain claims expressly recited the beneficial properties of LDX (e.g., sustained release), those claims merely duplicated the overarching inventive concept because the properties were inherent to LDX.

Obvious-to-try analysis. The FCA found no error in the FC’s finding that the key difference between the state of the art and the inventive concept was the compound LDX and its advantageous properties. In light of this gap, the claims of the 646 Patent were not obvious. The three obvious-to-try factors weighed in favour of inventiveness: it was not known or expected that LDX would have the advantageous properties, substantial work was needed to arrive at LDX, and there was no motivation to make LDX.

The asserted claims were not anticipated

Apotex argued that the FC had erred in finding that the 646 Patent claims were not anticipated by Australian Patent 1,965,054,168 (AU 168). AU 168 disclosed a class of “advantageous compounds”, one of which was LDX. Apotex argued that if AU 168 was performed across its breadth, then LDX would necessarily be made and therefore the 646 Patent claims were anticipated. Apotex also argued that the FC had erred by considering the advantageous properties of LDX without a finding that the 646 Patent is a “selection patent”.

The FCA rejected Apotex’s argument, holding that it “amounts to no more than an assertion that genus patents necessarily anticipate the chemical composition claims in species patents”, contrary to established precedent. The FCA focussed on the principle that the prior art must “necessarily infringe” in order to anticipate a claim. The FCA found that AU 168 was not anticipatory because there were numerous ways to perform it without making LDX.

Apotex Inc. v. Shire LLC, 2021 FCA 52