Défense réussie du brevet canadien VYVANSEMD de Takeda en appel (article en anglais)

The Federal Court of Appeal has dismissed two appeals^[1] brought by Apotex in respect of the validity of certain claims of Takeda’s (as Shire) Canadian Patent No. 2,527,646 (the "646 Patent") which covers, inter alia, lisdexamfetamine (LDX), the active ingredient in Takeda’s ADHD medication VYVANSE®.

In the Trial Decision^[2], Justice Fothergill held that the claims in issue of the 646 Patent were valid and would be infringed in the face of Apotex's obviousness, anticipation, overbreadth, and insufficiency allegations.  The Federal Court of Appeal's comprehensive reasons affirm both the validity of the 646 Patent and foundational principles of selection patents, anticipation, and obviousness.

No magic to the term "selection patent"

Many of Apotex's arguments on appeal were premised on its assertion that the 646 Patent was not a "selection patent", and its corresponding position that this precluded consideration of the advantages of the claimed subject-matter when assessing anticipation and obviousness. Though the 646 Patent claimed a compound (LDX) that possessed special advantages as compared with a previous genus patent within which LDX was encompassed, Apotex argued that the 646 Patent was not a selection patent because it did not specifically mention the genus patent in its disclosure.

The FCA rejected Apotex's argument in its entirety. First, the FCA confirmed that a "selection patent is a patent whose subject matter is a fraction of a larger known class which was the subject matter of a previous disclosure", citing the Supreme Court in Sanofi/Plavix.^[3] Second, the FCA affirmed that "the validity analysis does not change depending on whether the patent was formally classified as a selection patent or not."^[4] Rather, the classification of a patent as a selection simply assists the Court in understanding the "nature of the beast", particularly because, in selection patents, inventiveness often lies in "the making of the selected compound, coupled with its advantage or advantages."^[5]

It is not sufficient for a prior publication to merely "encompass" a claimed invention to anticipate

In essence, Apotex's anticipation argument was an assertion that a large class of compounds contained within a prior art genus disclosure necessarily anticipates a composition claim in a species patent (in this, the claim to LDX in the 646 Patent).^[6]  The FCA dismissed this position as amounting to "marked departure from established precedent"^[7] and instead applied the fundamental principles enunciated in Sanofi/Plavix, adopted from General Tire, and repeatedly adopted in Canadian jurisprudence.

In particular, the FCA made clear that accepting Apotex's argument would be inconsistent with the need for an anticipatory reference to plant its flag on the precise destination claimed in the patent at issue. Holding otherwise would be contrary to the General Tire "necessarily infringe" requirement.^[8]

The FCA also held that many elements of the 646 Patent's dependent claims, – therapeutic benefits, prolonged release, and the abuse-resistant properties of LDX – were not disclosed by the genus patent. In doing so, the FCA dismissed the Apotex argument that an advantageous property forming part of claimed subject-matter does not need to be specifically identified in a prior art reference for that reference to be anticipatory.

The inventive concept, properly construed and applied, remains the end point for the obviousness inquiry

At first instance, the Trial Judge found that: (i) LDX was not contemplated by the prior art and, in fact, the prior art taught away from it; (ii) the inventors conducted extensive work preceding the 646 Patent; and (iii) the field of research was unpredictable, expensive, time-consuming and complex.^[9] On appeal, Apotex argued that these factual findings were irrelevant because, in Apotex's view, the bare chemical compound LDX was the sole essential element of the claim. Apotex argued it was incorrect for the Trial Judge to define the inventive concept – the end point to the obviousness analysis – as including anything other than the bare chemical formulae itself.

The FCA dismissed Apotex's argument as, inter alia, conflating the exercise of claims construction with the obviousness analysis. It held that the common law principles continue to inform the obviousness analysis under s. 28.3 of the Patent Act, and re-affirmed that Sanofi/Plavix's instruction that the inventive concept is the end point to the obviousness analysis.^[10] The FCA further held that:

• The inventive concept of a claim is not necessarily limited to the essential elements of the claim itself;^[11] the purpose of the inventive concept (to inform the inquiry into "inventiveness") is different than the purpose of claim construction (to define the scope of protection afforded by a claim);^[12]
• Consistent with the fact that patents are granted for one invention (Patent Act s. 36), and consistent with Sanofi/Plavix, a single inventive concept across multiple claims is not improper on its face;^[13]
• Recourse to the patent's specification to determine the inventive concept is permissible, especially where the claims themselves do not allow the reader to "fully grasp the nature of the inventive concept."^[14] That said, it is the inventive concept of the claims in issue that is to be considered.^[15]

From this, the Trial Judge's obviousness analysis was affirmed. The FCA confirmed that the Trial Judge did not err in considering the unexpected and advantageous properties of LDX that distinguish it from the prior art as part of the obviousness analysis^[16] or in relying on factual findings that the prior art taught away from even trying to make LDX to address the problem identified in the prior art.^[17]

Conclusion

The FCA's decision provides important clarification on basic principles of selection, anticipation, and obviousness.

Takeda was represented by Gowling WLG's Jay Zakaib, Alex Gloor, and Adam Heckman.