THE PRIMARY JUDGE'S REASONING
38 NutraSweet argued before the primary judge that the invention identified in the Ajinomoto patent was obvious, and therefore failed the inventive step test. In support of that contention, NutraSweet relied upon a prior art base which consisted of the common general knowledge as at the priority date, together with the information contained in a single document - the Nofre Tinti specification.
39 It was common ground before his Honour that the Nofre Tinti specification was not, as at the priority date, part of the common general knowledge, within s 7(2). It followed that the only basis upon which the Nofre Tinti specification could be considered as part of the prior art base was if it fell within s 7(3). It was also common ground that unless the Nofre Tinti specification did form part of the prior art base, NutraSweet's challenge based on obviousness would fail.
40 The primary judge appreciated that the information contained in the Nofre Tinti specification could not be considered as part of the prior art base unless the document satisfied all of the conditions stipulated in s 7(3). In his Honour's reasons for judgment (at [44]-[46]), he found that those conditions were met but he did not address the requirement of s 7(3) in its earlier form that the information be "relevant to work in the relevant art" in Australia
41 The error was brought to his Honour's attention after he published his reasons for judgment. He did not invite further submissions from the parties, but simply indicated that he would deal with the matter. Subsequently, he issued a corrigendum pursuant to which he replaced the current version of s 7(3), which he had set out in his original reasons for judgment, with s 7(3) as it stood at the priority date. He did not otherwise amend his reasons for judgment. He did not explain why, in his view, the additional requirement that the information be "relevant to work in the relevant art" in Australia had been met. He did not indicate whether that was because he construed that expression in a particular way, or whether he was satisfied, on the evidence, that the condition was met.
42 His Honour's reasoning on the question of obviousness can be summarised as follows. He referred to s 7(2) and posited the relevant test as being whether, when compared with the prior art, the invention "would have been obvious to a person skilled in the relevant art in the light of the common general knowledge as it existed" at the priority date. He noted that this was to be assessed in light of the common general knowledge together with information in a document "publicly available" which the skilled person could "be reasonably expected to have ascertained, understood and regarded as relevant" and referred to the current version of s 7(3) in that regard.
43 The primary judge next observed that the test for obviousness under the Act differed from that under the Patents Act 1952 (Cth). Under the 1952 Act publications could not be taken into account if they did not form part of the common general knowledge: Minnesota Mining and Manufacturing Company v Beiersdorf (Australia) Ltd (1980) 144 CLR 253 at 292-293 per Aickin J. He said that by common general knowledge he meant knowledge that was in fact known or used by those who worked in the field of the invention. He said the approach under the former Act was regarded as too narrow, and that one purpose of the 1990 Act was to treat as part of the common general knowledge information publicly available anywhere in the world which the skilled person would find.
44 In construing s 7(3), his Honour first identified the characteristics of the person who was to decide obviousness. That was a "relevantly skilled person". This meant a person who had a "practical interest in the subject matter" of the invention: Catnic Components Ltd v Hill and Smith Ltd [1982] RPC 183 at 242 per Lord Diplock. His Honour found that this "practical interest" might entail a collection of skills and knowledge not found in an individual. Thus the relevant skilled person could be a team. In his Honour's words (at [28]):
"The skilled addressee is a team which is interested in the investigation of artificial sweeteners (alone or in combination) for industrial application. What this entails is the selection, evaluation and blending of artificial sweeteners. This will require a rudimentary knowledge of chemistry, some of the skills of a food technologist, an understanding of the sensory evaluation of foods, particularly sweeteners, and some appreciation of the commercial use and application of artificial sweeteners. It is not necessary for any member of the team to have the knowledge of a chemist who creates new compounds for use as a sweetening agent."
45 Having identified the "skilled team", his Honour proceeded to deal next with a pivotal point raised by Ajinomoto, namely that there was not in Australia a relevantly skilled person who was able to judge the obviousness of the claimed invention. His Honour explained how the point arose (at [29]):
"According to the evidence, no research is undertaken in Australia to identify or evaluate new compounds which may be blended to improve their sweetness quality. That work is done overseas. So, according to the argument, there is no person or team in Australia skilled in the relevant art. The consequence alleged is that the attack based on obviousness must fail."
46 The primary judge rejected this submission as being inconsistent with both authority and principle.
47 With regard to authority he referred to Gambro Pty Ltd v Fresenius Medical Care South East Asia Pty Ltd (2004) 61 IPR 442 where, as his Honour pointed out, the relevant skilled person was an individual involved in the design and improvement of dialysis machines and where there was no such person in Australia. The primary judge noted that this did not lead Allsop J to conclude that there could be no skilled person who could judge the inventiveness of the claimed invention.
48 With regard to principle the primary judge said (at [31]):
"As regards principle, the argument rests on the unstated assumption, which I do not accept as correct, that a patent can only be struck down for lack of an inventive step if there is some industry in Australia which would be affected by the grant of the patent. First, the assumption reads into the legislation something which is not able to be implied. Second, I simply do not accept the view that when, as here, there is information in Australia, including information in widely circulated international textbooks and journals, which would ordinarily be referred to by a person interested in the area, that information should be ignored when deciding whether an invention is obvious. If such information were to be ignored Australia would become a resting ground for bad patents."
49 His Honour added (at [32]):
"In any event, as the evidence here demonstrates, although the selection, testing and manufacture of blended compounds for use as a sweetening agent does not take place in Australia, there are persons who work in closely related areas who do have an interest in and understanding of the relevant information. Moreover, major manufacturers of intense sweeteners conduct a large part of their research on a global scale and recruit scientists both locally and from other countries, including Australia. That is sufficient, in my view, to consider what would have been in the common general knowledge of the hypothetical skilled addressee."
50 The primary judge then went on to consider, on the merits, whether Ajinomoto's claimed invention was obvious. He identified in an unexceptional way the various steps that would have to be followed in order to resolve that issue. He considered the position in England, and observed that the position in Australia under the Act was different. He traced the history of the Act back to the 1984 report of the Industrial Property Advisory Committee, Patents, Innovation and Competition in Australia (Report to the Honourable Barry O Jones MP, Minister for Science and Technology, Canberra, 29 August 1984) (the IPAC Report). It was at this point that he set out s 7(2) and (3) of the Act, and added that if a prior publication met each of the conditions contained in s 7(3) it would be considered along with the common general knowledge on the question of obviousness.
51 His Honour described the state of common general knowledge in Australia as at the priority date. He said that the search for an artificial sweetener that had taste characteristics as close to sucrose as possible, and which lacked the undesirable characteristics often associated with artificial sweeteners, had been going on for a considerable time. He said that no one artificial sweetener met all of the desired requirements for an ideal sweetener, especially when used in soft drinks. Importantly he found (at [41]):
"It was therefore common practice to blend intense sweeteners so that the limitations of one sweetener would be offset by the strengths of another. Blending of sweeteners had taken place since the 1960s."
52 The primary judge added that, as at the priority date, the characteristics of blended sweeteners were known. One characteristic was that blending could have a synergistic effect. It was not possible to predict with certainty whether a particular blend would have an additive or synergistic effect. For that reason, blending was described as a "complex" phenomenon, requiring sensory evaluation testing to be carried out. He said that the "odds" favoured a synergistic effect when certain known sweeteners were blended. Aspartame and Ace-K, in particular, were two compounds known for their synergistic effects when blended, especially when blended together.
53 His Honour reiterated that it was common ground that the Nofre Tinti specification was not part of the common general knowledge. He stated, however, (at [44]-[45]):
"It is nevertheless part of the information to be taken into account when considering what the skilled team would think and do. It is to be taken into account because it satisfies the conditions in s 7(3). As to this, the evidence is almost all one way. Each of Dr Bullock, Dr McBride, Dr Lindley and Mr Heyhoe said that if one were to embark upon a project to develop a new sweetener or sweetener blend, a search of the relevant patents would be undertaken. Dr Bullock is currently General Manager of the Sugar Research Institute in Queensland and has past experience as a patent examiner and chemist. He said that searches of patent and technical literature are a critical part of research and development. He explained that there were several obvious reasons for this, including "to familiarise the researcher with up to date developments, to provide inspiration and to 'avoid reinventing the wheel'." He added that these searches were also necessary to verify that there was "freedom to operate" in the field. Mr Heyhoe, a food technologist with a background in research and development, also put the matter quite firmly. He said that if he had been engaged to develop a new sweetener or blend: "[I]t is inconceivable to me that a literature search which included a search of patent literature would not be done as part of that work."
Only one witness, Mr Garrett, suggested that a literature search might not be undertaken. I say Mr Garrett only "suggested" this because all he said in this regard was that in his work before the priority date as a teacher in food science and technology at the William Angliss Institute he did not read patents. It is, I think, clear that the reason Mr Garrett did not read patents was that his work did not require him to do so. It was enough that he read synopses of patents."
54 Having summarised the evidence, his Honour concluded (at [46]) that once it was accepted, as he did accept, that a patent literature search would have been undertaken by the skilled team, there was no doubt that the Nofre Tinti specification would have been "ascertained" and "understood". That meant that these two requirements in s 7(3) were met. His Honour added that, in the end, he believed that this was accepted by Ajinomoto.
55 His Honour then turned to the third requirement, which he identified as simply that the Nofre Tinti specification would be regarded as relevant. He stated (at [47]-[48]):
"On this point, Dr Bullock, Dr McBride, Mr Heyhoe and Dr Lindley said that they would have regarded the Nofre Tinti specification as relevant to the task of developing a sweetener or sweetener composition. Dr McBride is a consultant psychophysicist with 18 years' experience in food research at CSIRO. He would have regarded it as relevant because he was aware beforehand that NutraSweet was developing a new generation sweetener. I think that what Dr McBride meant was the compounds in the Nofre Tinti specification were derivatives of aspartame, which was the most commercially successful artificial sweetener as at the priority date, and so were likely to be useful compounds. Moreover, one of the compounds, DMB-APM, had exceptional potency being 10,000 times as sweet as sucrose. Likewise, in Mr Heyhoe's opinion the Nofre Tinti patent would have been regarded as relevant because "a new sweetener based on Aspartame identifying high sweetener intensities with excellent organoleptic properties and stability would be highly attractive to commercial manufacturers." Similar considerations motivated Dr Lindley to consider the Nofre Tinti compounds as relevant.
Importantly, of the various compounds described in the Nofre Tinti specification, DMB-APM would have been regarded as the most suitable for use as an artificial sweetener. Dr McBride described this compound as the "preferred" compound based on its high intensity sweetness, organoleptic properties and reported similarities to aspartame. The principal reason was its potency. Dr McBride said its high potency would have both cost benefits to manufacturers as well as regulatory advantages because regulators invariably prefer smaller quantities of additives. Dr Bullock also described DMB-APM as "the preferred compound". Even Dr Prescott was prepared to concede that the characteristics of DMB-APM made it "a promising candidate [for] a high intensity artificial sweetener." To be fair, Dr Prescott made this comment in relation to the use of DMB-APM alone, not in combination with other sweeteners. In my opinion the evidence is overwhelming that DMB-APM was a "promising candidate" for blending as well."
56 After a brief discussion of the position in the United States, his Honour stated his conclusion regarding the obviousness of the Ajinomoto patent. He said (at [53]-[54]):
"In my view the evidence does establish that it would reasonably have been expected that a blend comprising DMB-APM and aspartame or aceK, or DMB-APM, aspartame and aceK would give a sweetness quality closer to that of sucrose than any one of those compounds individually. The common general knowledge strongly suggested this result. So did the witnesses. Mr Heyhoe, in particular, was a good witness on this aspect. He said the odds were 70 per cent in favour of synergy. Dr Bullock, whose evidence was compelling on many aspects, also favoured the gambler's approach and said the chance of a blend resulting in synergy was "odds-on". I also regard as important Dr Bullock's evidence that his first choice for blending with DMB-APM would have been those sweeteners that had already had commercial success and shown synergy when used in blends. So, aspartame and aceK were primary candidates.
I think this is a clear case of obviousness. This result should not come as a surprise. As long ago as 1993, Dr Eric Walters, a chemist who worked in the field, predicted that "[t]he time may be coming when simply blending sweeteners is no longer patentable because of its obviousness": E Walters, "High-Intensity Sweetener Blends: Sweet Choices" [1993] Food Product Design 83, 84."
57 In reaching that conclusion, his Honour expressly rejected the evidence of Ajinomoto's experts, Dr Prescott and Mr Garrett, to the effect that the skilled team would have found it surprising that the claimed invention gave a sweetness profile that was closer to that of sucrose. He explained that these experts had based their opinions upon taste profiles given in the Ajinomoto specification that did not accord with common general knowledge. In addition, he accepted the evidence of Dr Lindley and Mr Heyhoe, experts called on behalf of NutraSweet (at [55]). Their evidence was to the effect that the Ajinomoto taste profiles were simply incorrect. Those profiles exaggerated the negative aspects of DMB-APM, aspartame and Ace-K, and therefore overstated the positive aspects of the claimed invention.
58 As previously indicated, his Honour also dealt with NutraSweet's challenge to the Ajinomoto patent based on lack of novelty (close, but not quite) and its challenge based on lack of utility (rejected). He did not deal at all with the challenge based upon manner of manufacture.