Carrying on with our lively debate on the merits of the Supreme Court’s judgement in the Novartis case, Siva Thambisetty has sent us this reply to Darren’s rejoinder, which we had published over here. This is the first time we’ve had such an extended debate on the blog and I hope we can have more such debate on other aspects of IP law.
Impugning novelty the Novartis way
by Siva Thambisetty
I am really grateful to the exchange here and for comments below each of the posts. My remarks below are a much more explicit response to the specific claim that I may previously have endorsed a ‘category error’.
There is a difference between support for claim scope and enablement for novelty defeating purposes, particularly for complex disclosures. In my post, my remarks are based on the specific case of a simple generic disclosure with very few possible alternatives, that then leads to specific implications for novelty defeating enablement.
To make it very clear, I agree that Imatinib Mesylate would infringe a generic disclosure of Imatinib even where Imatinib Mesylate has not been enabled explicitly in the patent for Imatinib. Generally such claim scope is accepted because several factors such as nature of the invention, level of predictability in the field and knowledge of a person skilled in the art step in to shore up the implicit content of supporting disclosures. I maintain that it is important to keep the basis of such claim scope in mind even when we follow the rules as legal precepts. [To understand some of the longstanding tension in UK law between granting patents for chemical products and requiring that the scope of monopoly rights equiparate with the disclosure in the specification see Pila on Chemical Products and Proportionate Patents]
It is also true that in general, a generic disclosure (such as of Imatinib base compound) does not impugn novelty of a more specific claim (such as of Imatinib Mesylate) – usually individualized description is needed to make it prejudicial to novelty. The only way in which a generic disclosure can impugn novelty is where the generic disclosure can only result in a small number of possible alternatives/ or low number of significant compounds, in which case limited disclosure of a small number of possible alternatives may itself be regarded as disclosure of each and every member of that group. Salts of compounds are rarely an enablement issue. Again this is because of what we know and assume from the predictability of the field and the nature of the invention.
The Imatinib patent specifically included respective salts because of the close relationship between ‘novel compounds in their free form’ and in the ‘form of their salts’. Further the patent states that ‘reference to free compounds must be taken to include corresponding salts where appropriate and expedient.’ Usually claims of compounds are set forth with one or more derivatised forms such as salts, and preparation of salts of compounds are often routine and predictable in the pharmaceutical arts.
So while a product may be used (under patent or as infringing product) before the priority date, we cannot assume that such use amounts to disclosure and enablement enough to impugn novelty, without further enquiry based on common general knowledge. Given the close association between salts and the base compounds however, the court was justified in taking the generic disclosure of Imatinib as having impugned the novelty of specific salt – Imatinib Mesylate (but not the beta crystalline form; and stopping short here when polymorphism is known to exist, is a clue that the Supreme Court does actually, understand the context of novelty defeating disclosures. [para 124, and footnote]).
In this sense, I do see and acknowledge why reference to the infringement action might have been a red herring, but the court refers to the a) Patent Term Extension Application for the Zimmerman patent in the US (showing that the sole active ingredient in the drug marketed under the patent is Imatinib Mesylate) b) the Board of Patent Appeals decision reversing the rejection of a patent application on the beta crystalline form of Imatinib Mesylate (as demonstration of the need for specific teaching to impugn novelty) and c) the alleged infringement by VEENAT 100, to evidence at least two aspects relevant to impugning novelty. First that Imatinib Mesylate was made available to the public before the priority date. Secondly to highlight the kind of invention, generic nature of the disclosure, the level of predictability in the field due to which support and enablement in each case (or respective ‘category’ of infringement and novelty destroying disclosures) is comfortably matched because of conventional assumptions made in the field.
In terms of my comments on specialized nature of patent law, this is a question of institutional capability – we can disagree on whether there ought to be space for such diverging capability, and the difference in thinking that inevitably follows. If we regard the involvement of general appellate courts as unreliable/undesirable because they are prone to make ‘mistakes’ in a highly technical field, we risk losing valuable opportunities to test patent law against benchmarks of legitimacy that are different to the internal logics that we take for granted.