It may be that to pursue an exact definition of inventive step is both difficult and unnecessary. For guidance as to the patentability of an invention, the underlying social contract should be examined: 'Patents are granted for real advances in knowledge capable of industrial application'.128 An invention must contribute a new idea to the existing stock of knowledge. Lord Hoffmann has described three forms that this new idea could take:
Sometimes, it is the idea of using established techniques to do something which no one had previously thought of doing. In that case, the inventive step will be doing the new thing. Sometimes, it is finding a way of doing something which people had wanted to do but could not think how. The inventive idea would be the way of achieving the goal. In yet other cases, many people may have a general idea of how they might achieve a goal but not know how to solve a particular problem which stands in their way. If someone devises a way of solving the problem, his inventive step will be that solution but not the goal itself or the general method of achieving it.129
In short, these steps are the goal itself, the general method of achieving the goal, and the solution to a problem. If patents are to be granted for additions to the stock of human knowledge then whether the invention has solved some scientific uncertainty should be taken into account. As the techniques of genetic engineering become commonplace, the number of patents awarded for biotechnological inventions might be expected to decline. A vast array of materials, tools, and protocols developed by molecular biologists are now part of the art.130 Applying established techniques to achieve an identified goal is not within the scope of invention as defined by Lord Hoffmann. To do so would constitute an obvious developmental step.
Traditional plant breeding techniques for combining desirable characteristics from two plant varieties into one new variety would generally be considered obvious and therefore unpatentable.131 An exception to this proposition is the granting of a patent for a sunflower seed conventionally bred to have an oleic acid content of approximately 80% or greater.132 In this case, it was held that the existing wisdom in the prior art suggested that the course of breeding undertaken by the applicants would not have been successful.133 By achieving their goal, the applicants had shown that something previously thought not possible was, in fact, possible. This was held to be a sufficient contribution to the art to warrant the grant of a patent.
Scientific uncertainty is not to be equated with mere lack of information if the means to gather that information are readily available. Where DNA sequencing is done automatically by machine, mere sequencing of DNA can not be inventive. As described above,134 scientific progress involves building upon steps previously taken. One difficulty is that taking the next step may well involve solving scientific uncertainty but, equally, it may be seen as an obvious course to try. The question of obviousness may turn on the way in which the inventive concept is described. In Biogen Lord Hoffmann made the point that the level of generality at which the inventive step is stated is critical. Here, the patentee had chosen to pursue an identified goal by known means. Lord Hoffmann said: 'A proper statement of the inventive concept needs to include some express or implied reference to the problem which it required invention to overcome .135
Advances in science usually comprise a series of small steps. Each forward step is prompted by the preceding one. Biogen built on existing knowledge of recombinant DNA techniques to produce recombinant DNA molecules coding for Hepatitis B virus (HBV) core and surface antigenic polypeptides, and successfully produced these polypeptides in prokaryotic cells. Recombinant DNA techniques were well established at that time, but it was not known whether the DNA contained in the Dane particle (the identified HBV infective agent) carried the genes encoding the viral antigen proteins. It was also not known whether prokaryotic cells transformed with eukaryotic genomic DNA could successfully transcribe and translate these genes into proteins.
Previously recombinant DNA techniques had been shown to be capable of expressing eukaryotic genes obtained from mRNA in prokaryote cells. However, no mRNA for the HBV antigenic proteins were available. Biogen attempted to express large fragments of the HBV genomic DNA in the hope that among the fragments would be a piece large enough to be expressed in the host cell and that would exhibit HBV antigenic activity. The attempt was successful. The uncertainty surrounding expression of eukaryotic genes in bacterial host cells meant that the probability of success was low. The Court of Appeal (UK) found that the decision to express a polypeptide displaying HBV antigen specificity in a suitable host generated no new teaching, and so declared the patent invalid for lack of an inventive step.136 Yet, an addition to the stock of human knowledge had been made by Biogen in providing answers to the two unknown questions that had persuaded expert opinion to rate the chances of success as low. In the House of Lords, Lord Hoffmann agreed that so stated the alleged inventive step was obvious.137 However, when the invention was described with greater particularity the argument for the existence of an inventive step was much stronger. Lord Hoffmann characterised the inventive step as 'the idea of trying to express unsequenced eukaryotic DNA in a prokaryotic host'.138 In taking this step, Biogen addressed the uncertainty of using recombinant DNA techniques to express eukaryotic proteins in bacterial (prokaryotic) host cells.
The decision in Biogen poses a challenge to patent applicants to state the invention at an appropriate level of generality. Too high a level and the patent will be vulnerable to an attack on the ground of obviousness, and the claim may be too broad. On the other hand, too narrow a claim will facilitate competitors inventing around the patent to avoid infringement. This position, reached by considering the level of abstraction at which the inventive step is stated, is in accord with the social contract rationale for the patent system. A monopoly should be granted that is commensurate with the actual contribution to the art made by the inventor. Biogen did not invent the first method of expressing eukaryotic proteins by introducing recombinant DNA molecules into bacterial cells, but they did invent one way of using recombined genomic DNA to express HBV antigenic proteins in prokaryotes. Biogen was entitled to a patent for this invention. The reason that the patent was held invalid was because Biogen claimed a larger monopoly than they were entitled to under the patent social contract. This related issue, the scope of the patent claim, is considered next.