In a recent High Court decision, HHJ Hacon made clear that the inventive concept of a patent (for the purposes of both validity and infringement) cannot be stretched to constitute a concept outside that which was claimed. This is because the invention is prima facie that specified in the claim, the inventive concept is the core of the of the invention claimed, therefore the inventive concept of a claim cannot encompass matter which forms no part of the invention as a whole, i.e. that which is not specified in the claim. This meant that when identifying the inventive concept, features claimed could not be ignored and features not claimed but considered in the specification must be excluded. On this basis, HHJ Hacon found that both of Novartis’ patents lacked inventive step over the cited prior art, and that Teva’s product did not infringe either on normal construction or on the basis of equivalence.
Teva brought revocation proceedings against two Novartis formulation patents: EP 29 64 202 and EP 31 24 018 (the Patents). The Patents concerned a tablet formulation for deferasirox, which had previously only been available in dispersible form. Deferarisox is used to treat iron overload, in particular in patients with sickle cell anaemia, Thalassemia and other blood conditions. Teva also sought a declaration of non-infringement for its product “Teva DFX”. Novartis counterclaimed, alleging infringement of both patents on the basis that Teva DFX was an equivalent of the product claimed by each of the Patents.
Novartis originally formulated the inventive concept of both Patents as the provision of a swallowable film-coated tablet containing a high load of deferasirox with the excipients claimed (without sodium lauryl sulfate and lactose) having higher bioavailability (and/ or additional benefits) compared with the previously known dispersible tablets. In closing, Novartis added another aspect: the provision of a tablet having a reduced food effect, i.e. can be taken with a light meal as opposed to an empty stomach. Novartis put the higher bioavailability and reduced food effect front and centre of their characterisation of the inventive concept. In contrast they sought to ignore the claimed range of deferasirox (45-60% of the total weight in the claim). By implication Novartis submitted that it is irrelevant to the inventive concept.
Teva submitted that the range of deferasirox was the key feature of the inventive concept, i.e. it was simply a film-coated tablet formulation with an amount of 45-60% deferasirox.
HHJ Hacon, helpfully set out the law covering inventive concept generally and noted that “[t]he invention is prima facie that specified in the claim: see s.125(1) of the 1977 Act and Conor Medsystems Inc v Angiotech Pharmaceuticals Inc  UKHL 49, at . There is no reason to suppose otherwise in the present case. The inventive concept is the core of the of the invention claimed, see Actavis UK Ltd v Eli Lilly & Co.  UKSC 48, at . Therefore the inventive concept of a claim cannot encompass matter which forms no part of the invention as a whole.”
The argument was focussed therefore on whether the features not found in the claim (here higher bioavailability and reduced food effect) still formed part of the invention as claimed and thus the inventive concept. Novartis advanced three arguments of law in support of their position (all which failed).
- The first was that invention may lie in discovering that a product has a particular property. This will give rise to a valid claim even if there is nothing inventive in making the product. HHJ Hacon, when considering the case law raised in support of this position made clear that this was correct where the purpose of the invention (e.g. in Conor Medsystems it was a claim to a stent coated with taxol “for treating or preventing recurrent stenosis”) was at the core of the invention “as claimed” and thus would form part of the inventive concept. It should be noted that HJ Hacon was clear that this is not the same as determining the technical contribution for the purposes of considering whether the claims constituted an arbitrary selection.
- The second was that taking into account the technical effects of the claimed tablets as disclosed in the specification of the Patents aligns with the problem-solution approach of the EPO. HHJ Hacon, considered and compared the EPO problem solution and Pozzoli approach noting that although in this context a different position may result from the EPO approach, in any event, he was bound by the relevant part of the Pozzoli decision that requires the court to compare the inventive concept, or the invention as claimed, with the prior art.
- The third was that it is not possible to ask and answer the questions set out by the Supreme Court in Actavis UK Ltd v Eli Lilly & Co  UKSC 48, at , in relation to infringement of a claim without reference to the technical effects of the invention claimed, even if those effects form no part of the claims (and that the inventive concept ought to be the same for validity and infringement). Whilst HHJ Hacon agreed that inventive concept of a claim should be the same for all purposes he noted that the inventive concept is the new technical insight conveyed by the invention, and the invention is that which is claimed. It was also viewed by HHJ Hacon as a matter of construction, “although the description of the invention and the drawings are to be used to interpret the claims (see art.69 European Patent Convention), features disclosed only in the description are not to imported into a claim to impose a limitation that would not otherwise be there”.
It was made clear that this approach does not impact an inventive step assessment where it is argued there is a lack of a contribution to the art. In that context the identified technical advantage discussed in the specification, if plausible, would form part of the inventive step assessment. As HHJ Hacon put it “[i]f the stated technical advantage is plausible so that the patentee has made a contribution to the art, the claim will not be found invalid as an arbitrary selection, whether for lack of inventive step […] or for insufficiency […]. However, such a finding has no bearing on the separate issue as to whether the product is obvious over the prior art.”
When considering the facts of this case, HHJ Hacon held that the reduced food effect and increased bioavailability did not form part of the invention as claimed. The invention was the swallowable tablet, with the claimed range of deferasirox and excipients. The technical effects of bioavailability and reduced food effect were not mentioned in the language of the claims and could therefore not form part of the inventive concept.
Teva asserted 3 pieces of prior art, two formulation patents (“Battung” and “Zadok”) and an article authored by Novartis’s employees on dispersal of dispersible deferasirox (‘Sechaud’). The Patents were found to lack an inventive step over Battung and Zadok.
Applying the four-part approach in Pozzoli and relying on the inventive concept of the patents considered above, the Court held that if the skilled team at the priority date had decided to reformulate deferasirox into a swallowable film-coated product, selecting the relevant excipient and surfactant would have been obvious to try with a reasonable expectation of success. In addition, there was no perceived technical barrier to making a product falling within the claims of the Patents. It did not matter that there would have been limited commercial pressure to undertake this reformulation.
Teva DFX was found not to infringe the Patents either on a normal construction (as was common ground) or under the doctrine of equivalence. The amount of deferasirox in Teva DFX was confidential however it was found to be above the claimed range of 45-60%. On equivalence, HHJ Hacon held that, in this case, the inventive concept of the Patents would be seen by the skilled team as requiring strict compliance with the 45-60% range of deferasirox. On that basis, a variant would not be substantially the same as the inventive concept unless it strictly complied with that range. However, it was made clear that a numerical range may be more or less strictly applied in determining the scope of a claim, depending on all relevant facts.
This case provides some guidance as to how courts may approach the question of inventive concept in the future, particularly in the context of assessing infringement under the doctrine of equivalence. The case suggests that the courts will take a narrower approach to construing the inventive concept of a patent, focussed on the clear language of the claims rather than technical advantages set out in the specification.
Co-authored by Sophie Davison, Trainee Solicitor