By Nicola Dagg of Allen & Overy
The requirement that a patent specification must disclose the invention in a manner that is “clear enough and complete enough for it to be performed by a person skilled in the art” (UK Patents Act/EPC) represents a significant source of commercial uncertainty for patentees.
This is particularly the case in areas of biotechnology. While the basic object of the provision is clear – it enables others to make practical use of the technology after the monopoly period is over – the question of what constitutes “enough” clarity and “enough” completeness in any particular case can be uncertain and difficult to predict.
The sufficiency requirement reflects the underlying policy principle that the scope of the monopoly granted to the patentee must be justified by the technical contribution the patent makes to the art. The need for fair protection governs both the consideration of the scope of claims and the requirement for sufficient disclosure. The patentee is not entitled to monopolise more than it has disclosed to the public. In modern UK patent law, insufficiency includes (among other things) both “classical” insufficiency, ie, that the specification does not give enough detail to enable the skilled person to perform the invention without undue burden, and “Biogen” insufficiency or excessive claim breadth. Adding a further layer of uncertainty in some cases, the requirement of “plausibility” has increasingly been examined in the context of sufficiency.
Sufficiency is judged on the basis that the skilled person will use his or her common general knowledge to:
The skilled worker does not need to be given every detail or told what is self-evident. However, he or she should not be required to carry out prolonged research, inquiry or experiment. Above all, he or she must not be required to be inventive over and above what is taught in the patent.
The question whether the time and energy the skilled person needs to implement the patent constitutes an undue burden is highly fact specific. The nature of the skilled person (e.g. technician or senior scientist, pharmacologist or clinician), the composition of the skilled team, the extent of the common general knowledge and the expectations that exist in the particular field are crucial, and these questions are often hard-fought in litigation.
If the invention involves complex technology in uncharted waters, the amount of work the skilled team needs to undertake may be extensive, and the skilled team may be highly qualified and experienced in difficult techniques. It may take years, particularly if it is a pioneering invention, because the techniques needed may have been in their infancy at the date of priority. This does not necessarily result in insufficiency. In Halliburton Energy Services v Smith International (2006) the Court of Appeal warned against “imposing too high a standard of disclosure merely because the subject matter is inherently complex”.
The fact that the specification contains an error or an untested instruction will not necessarily be fatal. In Synthon BV v SmithKline (House of Lords, 2006) the main example referred to a solvent (ethanol) that would not have worked. The evidence was, however, that the skilled person, relying on his or her common general knowledge, would have substituted a different solvent that worked.
As so often in patent cases the quality of the expert and other witnesses will be crucial in these fact-intensive areas. The court is likely to give more weight to the evidence of those who have first-hand experience of working in the field at the relevant time, so identifying such witnesses at an early stage can often make the difference between success and failure.
“Biogen” insufficiency is centred on the need for the specification to enable the invention to be performed to the “full extent of the monopoly claimed”, i.e. the claims must not cover products or processes which owe nothing to the teaching of the patent and which the specification does not teach the skilled person how to make or carry out. Biogen’s patent claimed a recombinant DNA molecule with certain characteristics related to the production of antigens of the hepatitis B virus (Biogen v Medeva, House of Lords, 1996). It was a “product-by-process” claim, defining the invention partly by reference to the product (the molecule) and partly by reference to the way it was made (“recombinant”). However, whereas Biogen had only disclosed one way of making the molecule, the claim covered all ways of making it (“recombinant”), thus effectively monopolising all future methods of producing the molecule by genetic engineering and potentially stifling further research in this area. This was held to be too broad.
In contrast, in Genentech I/Polypeptide Expression (T292/85), cited in Biogen, the claim was essentially to a plasmid with certain features including heterologous DNA which was suitable for transforming a bacterial host resulting in an expression product. There was no limitation to a particular plasmid, a particular heterologous gene or a particular bacterial host. The claim covered embodiments that were not enabled. The Board concluded that unless the claims also embraced variants of components which were, or later would be, equally suitable to achieve the same effect in a way that could not have been envisaged without the invention, the protection provided by the patent would be ineffectual.
In T0636/97 erythropoietin II/Kirin Amgen the Board stated that a claim can validly cover broad subject matter, even though the patent specification does not enable every method of arriving at that subject matter. Without this, in many biotechnology cases, patent protection would be illusory.
Biogen insufficiency is often an issue where the invention covers a class of products. In principle, the patent specification must enable the invention to be performed in relation to each individual product in the class. However, if the patentee can identify a principle of general application, a common thread that links the members of the class, it may be able to make a claim in general terms to the class as a whole. Lord Hoffman elaborated on this idea of a “principle of general application” in the later case of Kirin Amgen v Hoechst Marion Roussel (House of Lords, 2005). He stated that “such a claim is sufficiently enabled if one can reasonably expect the invention to work with anything which falls within the general term.” An objection had been raised that the claim should be limited to expression in CHO cells, as this was the expression system that was enabled by the specification. Lord Hoffman observed that the patentee should be entitled to cover expression of EPO through improved expression systems which were not enabled by the patent specification.
The general term may describe an invention of significant breadth or it may be much more “humble”; for example, reference to a “connecting means” will be a principle of general application if the invention would work with substantially any connecting means. It does not, of course, follow that the principle of general application must cover improvements. It is the original invention that must be enabled. In Biogen, Lord Hoffman gave the example of the Wright Brothers, who showed that heavier-than-air flight was possible. This did not entitle them to a monopoly of all heavier-than-air flying machines. It is only the invention claimed that has to be enabled, not any embodiments that extend beyond it, although such embodiments may infringe.
A claim to a product is sufficiently disclosed if one way of making it is disclosed. The patentee may then claim the product as such. This point was made in Generics v Lundbeck (House of Lords, 2009). Lundbeck had found a way of separating the enantiomers of their anti-depressant drug citalopram and claimed a patent for escitalopram. There was nothing inventive in the idea of separating the enantiomers, but the method by which this was achieved represented a significant advance. The question was whether Lundbeck could claim the enantiomer as a product or whether it could only claim the method. The House of Lords held that Lundbeck was entitled to claim the product itself (the enantiomer), however obtained, as it had made this product available – this was the technical contribution. The decision revolves around the nature of the invention and the technical contribution, is it the product as in Generics v Lundbeck or is it the way of making it as in Biogen? This is a fine line, which may be difficult to guage in some cases. It is sometimes a feature of patent disputes in the biotechnology field that a later competitor is making an infringing product using more advanced methods, which may be inventive in themselves. If the original claim was to a product rather than a process the competitor will infringe.
The concept of plausibility has its origin in the case law of the Technical Boards of Appeal. As described by Lord Hoffman in Conor Medsystems v Angiotech, it requires the patent to “pass the threshold test of disclosing enough to make the invention plausible”. The question is not, as in classical insufficiency, whether the invention can be performed by the skilled reader, but whether, at the date of application, it is plausible or credible that the invention will work. Echoing Biogen, this includes it being plausible that it will work with “substantially everything falling within the scope of the claim”.
The requirement for plausibility as expressed by the Court of Appeal in Regeneron v Genentech (2013) is that the patent specification and CGT together must provide enough information to allow a “reasonable prediction” to be made at the time of application that the invention will work “with substantially everything falling within the scope of the claim”. This case concerned a patent for the use of VEGF antagonists to treat non-cancerous (non-neoplastic) diseases characterised by excessive blood vessel growth and claimed anti-VEGF antagonism as a treatment for all such diseases. This was a broad claim, but it was upheld by Kitchin LJ in the Court of Appeal on the basis that the patent disclosed a principle of general application which made it plausible that this would work across the scope of the claim. This conclusion was based on, among other things, on a general view in the art at the time that all such diseases were linked by the common thread of angiogenesis. The inventors had shown that blockade of VEGF worked to prevent angiogenesis in tumours, making it reasonable to suppose that VEGF antagonists would work with other such diseases too. The requirement is that it should apply to “substantially” all such diseases. As made clear by Birss J in the recent case of Merck v Ono (High Court, October 2015), the fact that some such diseases cannot be treated need not be fatal.
For now it seems that the plausibility test will be used to weed out purely speculative patent claims, and will no doubt continue to play an important role in medical use claims.
Despite the fundamental difficulties in applying the principles of sufficiency as outlined above, it is key to first understand the true and fair nature of the technical contribution of the patent. What is the invention? What is its significance? What benefits does it bring? Is it a principle of general application? Only once that is identified can the insufficiency assessment properly be carried out. For Biogen insufficiency it will be key to consider whether that technical contribution can be achieved across the scope of the claim. If the technical contribution is a product then the claim will be sufficient so long as one way of achieving the product has been enabled. For a process claim one will need to determine what is required to work the claim and whether that is enabled. If the invention amounts to a “principle of general application” then other (non-enabled) variants may be embraced within the claim, and the claim will still be sufficient.
To “serve things up sufficiently” – that is, to pass the legal test – the true nature of the technical contribution will need to be on a silver platter for all to see and appreciate.