In the recent case of Ajinomoto Co Inc v Nutrasweet Australia Pty Ltd [2008] FCAFC 34, the Full Federal Court considered the construction of section 7(3) of the Patents Act 1990 (Cth) ("Act"), which defines the prior art base for the purposes of assessing inventive step. The decision is relevant for s7(3) prior to the statutory amendments introduced by the Patents Amendment Act 2001 (Cth), and is therefore important for patents having a filing date before 1 April 2002. In particular, the decision is important because of the Court's construction of the phrase "relevant to work in the relevant art in [Australia]" as well as its findings on the admissibility of a relevant piece of prior art as evidence of obviousness.

In summary:

  • the phrase "work in the relevant art in [Australia]" extends to work that has actually been carried out in Australia, and does not include hypothetical work (that is work that was never in fact undertaken in Australia).
  • the phrase "work in the relevant art in [Australia]" was removed from the Act in 2001 for patent applications lodged after 1 April 2002, however s7(3) still requires that a prior art document be "relevant".
  • the word "relevant" does not attract a requirement that the document, or a specific disclosure within the document, "stand out from the crowd" of possible relevant documents as the solution to the problem.

Background to the Judgement

Ajinomoto is the proprietor of Australian Patent No. 727199, entitled "Sweetener composition improved in taste". NutraSweet holds an earlier patent for an artificial sweetener (Australian Patent No 664663, the "Noffre Tinti" specification), and markets the artificial sweetener under the trade name "Neotame". The invention claimed by the Ajinomoto patent is essentially a combination or blend of the known high intensity sweeteners Neotame and aspartame and/or acesulfame K ("AceK").

In 2002, NutraSweet instituted proceedings against Ajinomoto seeking revocation of Patent No. 727199.

It argued that the Ajinomoto patent was invalid on a number of grounds, including lack of inventive step in view of the common general knowledge in the field when combined with the Noffre Tinti specification. On 28 October 2005, Justice Finkelstein accepted NutraSweet's challenge to the validity of the Ajinomoto patent on the basis of inventive step and ordered that the patent be revoked.

On appeal, Ajinomoto argued that s7(3) could not be invoked as the basis for reliance upon the Noffre Tinti specification since there was no "work in the relevant art" undertaken in Australia and since, according to the evidence, no research was undertaken in Australia to identify new sweetening compounds. Further,

Ajinomoto argued that Nutrasweet's case failed since the Noffre Tinti specification was only able to be identified as "relevant" with hindsight as there was no evidence demonstrating that compound six within the Noffre Tinti specification, which is in fact Neotame, "stood out from the crowd". Ajinomoto further argued that the final words "to work in the relevant art in the patent area" in s7(3) imported a requirement that there actually be work in the relevant art in the patent area (i.e. within Australia), and that the expression does not extend to hypothetical work that could have been performed here.

Relevant to work in the relevant art in Australia

The Full Court gave the expression "work in the relevant art in [Australia]" its ordinary and natural meaning, and held that work means work that has actually been carried out in Australia. It does not include hypothetical work (that is, work that was never in fact undertaken in Australia).

However, Ajinomoto was ultimately unsuccessful on appeal because Patent No. 727199 related to a novel blend of known sweetening compounds and not a novel sweetening compound, per se. The Full Court noted that the evidence showed that blending of known sweetening compounds did occur within Australia as at the priority date, and in fact that such blending had taken place in Australia since the 1960s. As such, the "relevant art" was the blending of known sweeteners, rather than the creation of new sweeteners, per se. Hence, there was work in the "relevant art" in Australia, and the earlier NutraSweet patent was available to be combined with the common general knowledge.

Requirements to "stand out from the crowd"

Despite the above finding, Ajinomoto argued that s7(3) requires that the particular document "stand out from the crowd". However, the Full Court did not accept Ajinomoto's submission on this point, and in any event even if the Full Court had accepted Ajinomoto's submission there was in fact evidence from Nutrasweet's witnesses explaining why they would have selected compound six from Noffre Tinti as a prime candidate for their sweetener blend. Ajinomoto would, therefore, still have lost the appeal. As a result, the Full Court dismissed the appeal against the revocation of the Ajinomoto patent.

The content of this article is intended to provide a general guide to the subject matter. Specialist advice should be sought about your specific circumstances.