A case for our times: Ambiguity, insufficiency and uncertainty (Anan Kasei v Neo [2019] EWCA Civ 1646)

Readers may be tired of the current political milieu of ambiguity and uncertainty. Thankfully, this is a patent case, not another episode in the UK's political drama. In Neo v Anan Kasei ([2019]EWCA Civ 1646) the Court of Appeal again considered the thorny issue of insufficiency, both the Kirin-Amgen and the Biogen kind. The Court first had to construe the meaning of the term "consisting essential of" in the claim. The Court then had to determine if the invention could be performed and if the invention was disclosed by the patent across the whole scope of the claim. 

Case Background

The appeal was from a High Court revocation decision ([2018] EWHC 843 (Pat)) relating to Anan Kasei's European (UK) patent (EP 1435338). The patent claimed an improved version of the catalyst ceric oxide. Ceric oxide is particularly useful as a purifier of car exhausts. A revocation action was brought by Neo as a counterclaim to an infringement suit from Anan Kasei. In the High Court, Mr Roger Wyand QC, sitting as the deputy judge, maintained the patent. Mr Wyand rejected Neo’s arguments that the patent was obvious and insufficiently disclosed. 

What does “consisting essentially of” mean?

As every fledgling patent attorney knows, certain terms acquire special meanings when used in a patent claim. “Comprising” means “included but not limited to”. “Consisting of” means that nothing else is present. According to the EPO “consisting essentially of” should be interpreted as meaning that “specific further components can be present, namely those not materially affecting the essential characteristics” of the product in question (T 759/10, r. 3.4).

Penumbra

In the case in question, claim 1 as granted specified a ceric oxide consisting essentially of ceric oxide. Functional characteristics of the ceric oxide were also specified. As pointed out by Lord Justice Floyd, “the fact that the ceric oxide of the claim ‘consists essentially of ceric oxide’ might be thought to be a tautology”. 

In construing the claim, Lord Justice Floyd poetically re-phrased the EPO definition of “consisting essentially of” as providing a “penumbra around the core of the claim”. Additionally, “how much of a penumbra is determined by the point at which the added ingredient starts to have a material effect on the essential characteristics of the product” (para. 14). The parties agreed with this interpretation. The issue then became whether, given this definition, a skilled person would thus be able to perform the invention.

Kirin-Amgen insufficiency: Ambiguity and uncertainty

Lord Justice Floyd phrased Neo’s first insufficiency attack as being that the claim was conceptually uncertain. The key case defining this kind of insufficiency is Kirin Amgen ([2004] UKHL 46). In Kirin Amgen, the invention of recombinant erythropoietin (rEPO) was defined by having a higher than urinary EPO (uEPO). The problem was that the molecular weight of uEPO was not known and varied according to source and isolation method. The scope of the claim was thus rendered uncertain (in Lord Justice Floyd preferred wording) or ambiguous (in Lord Justice Lewison’s preferred wording).

Neo argued that a skilled person would be uncertain as to whether a ceric oxide fell within the scope of the claim or not. A skilled person would have to determine whether any additional ingredients in the ceric oxide materially affected the ceric oxide's characteristics. In order to determine this, the skilled person would have to do a side-by-side comparison between the ceric oxide and a ceric oxide that was identical but lacking the additional ingredient. The skilled person would therefore be faced with a) the impossible task of removing an ingredient from a baked ceric oxide (in order to produce a ceric oxide for the comparison test), or b) working out how to make the ceric oxide from scratch.

However, Lord Justice Floyd rejected the suggestion that a skilled person would have to make a product lacking the extra ingredient for comparison. Instead, Lord Justice Floyd accepted the expert evidence that a skilled person would be able to chemically analyse the product and make a judgement about whether individual components materially affected the product's characteristics. The claim of insufficiency due to uncertainty was therefore dismissed.

Biogen insufficiency: Enablement over the entire scope of the claim

Lord Hoffman established in Biogen Inc v Medeva plc [1997] RPC 1, that a specification must enable the invention to be performed across the full scope of the claim. In other words, the patentee cannot claim more than he has disclosed how to achieve. This does not mean that the patentee must necessarily enable all possible embodiments falling within the scope of the claim.  A claim to a compound, for example, is enabled by the disclosure in the specification of just one method to make the compound, even if other methods are available (see also Case Law of the Boards of Appeal, II.C.6.1.2). However, if a claim is directed to a product with functional properties, the claim may extend to products that owe nothing to the patentee’s contribution to the art. Such a claim would not be enabled over its entire scope.

The claim in the case in question defined the ceric oxide in terms of its functional properties. Neo argued that the claim therefore amounted to a wish list and was not enabled across its entire scope. The claim particularly specified that the ceric oxide “has a specific surface area of not smaller than 30.0 m²/g when subjected to calcination at 900°C for 5 hours."

Neo argued that the surface area of ceric oxide is greatly influenced by its morphology. Furthermore, ceric oxide morphology is itself highly dependent on the method of synthesis. As such, Neo argued that the claim covered subject-matter that owed nothing to the technical contribution of the patent. Particularly, a wide range of ceric oxide morphologies were possible under the scope of the claim but the patent only enabled those that could be produced by the methods disclosed in the specification.

However, Lord Justice Floyd found that Neo’s mere assertion that there were embodiments covered by the patent that could not be made was not enough: “Neo had to go further. They had to positively establish that there were structures which were covered by the claim which could not be made with the benefit of that teaching…the missing link in Neo's case, as it seems to me, is the lack of any evidence that there are structures which fall within the claim but which could not be made using the body of teaching in the patent” (para. 59-61).

Lord Justice Floyd’s reasoning chimes with the Case Law of the Boards of Appeal, which states that “an application may only be objected to for lack of sufficient disclosure if there are serious doubts, substantiated by verifiable facts” (Case Law of the Boards of Appeal, II, C.6.1.4). 

Lord Justice Floyd therefore upheld the High Court’s decision, and rejected Neo’s insufficiency attack.