The Patents Act 1953 is based on the British Patents Act 1949 and provides for the grant of letters patent for inventions. To qualify for a patent an invention must be sufficiently and fairly described, novel and inventive. The Act defines an invention as 'any manner of new manufacture the subject of letters patent and grant of privilege within s 6 of the Statute of Monopolies'.46 The phrase 'manner of new manufacture' derives from the Statute ofMonopolies 1623 which banned all monopolies except those for inventions.
Manner of new manufacture
Through the application of 'judicial ingenuity',47 the concept of 'manner of new manufacture' has served as the basis for defining patentable inventions throughout British law countries since 1623, successfully accommodating advances in technology. The scope of the term 'invention' was examined by the Court of Appeal in Pharmaceutical Management Agency Ltd v Commissioner of Patents,48 where a lengthy passage from the judgment of the High Court of Australia in the NRDC49 case was recited. This passage rejected any attempt to reduce the concept of invention to an exact verbal formula as unsound, and stated that the inquiry should be: 'is this a proper subject of letters patent according to the principles which have been developed for the application of s 6 of the Statute ofMonopolies?'50 This question should be considered in light of the purpose of s 6 which 'was to allow the use of the prerogative to encourage national development in a field which already, in 1623, was seen to be excitingly unpredictable'.51 One limitation seen as inherent in the concept of manner of new manufacture is that the invention must be useful. Proving utility is rarely a problem for patent applicants, probably because few people would go to the trouble and expense of patenting a useless invention. This requirement also underlines the distinction that patent law is concerned with the world of commerce and not basic research. However, the debate in the USA over the patentability of short fragments of DNA, called expressed sequence tags (or ESTs), has focused on the requirement of utility.
Early gene patents generally had well-defined utility because the protein that the gene encoded was well characterised and its function within the cell was known. Recent advances have allowed researchers to locate genes for which no function is known using ESTs. The question that has arisen is whether the use of an EST to locate a gene of unknown function is sufficient to warrant patent protection for that EST, and even for the full gene itself. In response to criticism of such patent applications from scientists, who feared that EST patents would restrict the freedom to pursue further research into the parent genes,52 the US Patent and Trademark Office has said that these applications 'must demonstrate a more substantial, real-world utility' .53 This issue is discussed later in the context of the patentability of research tools where it is suggested that rather than raising the bar on patentability by requiring a more substantial utility for the invention, the focus should be on limiting the scope of the patent claim, so that it is commensurate with the technical contribution to the art made by the inventor. In particular, a claim to an EST should confer a right to that EST alone, and general claim language extending the scope of the patent to include full length parent genes of the EST should not be allowed.54 The Court of Appeal has noted that as a signatory of the TRIPs agreement New Zealand is obliged to make available patents 'for any inventions, whether products or processes, in all fields of technology'.55 Natural products and naturally occurring DNA sequences cannot be patented in their natural source or environment because they are not new or inventive.56 However, the discovery of a product of nature, and the industrial application of that discovery, is an invention. Patents are available for the products of human invention. Where the invention involves the isolation, purification or recombination of naturally occurring genes or substances, these can be claimed as inventions but the claim 'shall be construed as not extending to that substance when found in nature'.57 This means that a patent for the synthetic production of human insulin using an isolated DNA sequence is not infringed by the production of human insulin in the body. On the other hand, those who get injections of human insulin produced by a biotechnological process have to pay a royalty to the inventors who developed an industrial application of the natural production of insulin.
The invention must have some new characteristic which is not known in the body of existing knowledge. An application for the grant of letters patent will be subject to examination to determine whether or not the claimed invention is anticipated by prior publication.58 Lack of novelty is a ground for opposition to the grant of a patent where 'the invention has been published before the priority date in New Zealand'.59 There is an important exception to this rule. A paper presented to a learned society by the inventor does not constitute prior publication.60 This position is consistent with the encouragement of research and development, through the dissemination of new information: a key part of the rationale for the patent system.
The inventive step
In Ancare Gault J said, 'Patents are granted for real advances in knowledge capable of industrial application.61 In Biogen Lord Hoffmann said, 'Whenever anything inventive is done for the first time it is the result of the addition of anew idea to the existing stock of knowledge'.62 If there is no addition to the stock of knowledge, there can be no patent. The evaluation of an inventive step, embodied in the patentee's claim, requires an analysis of whether the degree of difference between the invention and the state of the prior art is sufficient to warrant the grant of a patent monopoly. In the words of Lord Westbury:
there would be no end to the interference with trade and with the liberty of adopting any mechanical contrivance, if every slight difference in the application of a well-known thing should be held to constitute ground for a patent.63
Thus, the requirement of an inventive step is rooted in a public interest consideration.
The 'inventive step' so required is a concept that has eluded precise definition, and has therefore been judged, in a negative sense, by its absence. It is common for defendants in infringement actions to challenge the validity of a patent on the ground it lacks an inventive step. There are two provisions in the Patents Act 1953 providing for the revocation of a patent on the ground of lack of inventive step. First, opponents can contest the applicant's right to a patent in a hearing before the Commissioner of Patents on the ground the invention is 'obvious and clearly does not involve any inventive step' having regard to matter published (prior knowledge) or what was used in New Zealand before the priority date of the applicant's claim.64 Secondly, once a patent has been granted, the validity of that patent can be contested in the High Court on a similar ground.65 The Court of Appeal has endorsed the well-established test for obviousness:
It postulates a person (or, where appropriate, a team) skilled in the field but not inventive, invested with the common general knowledge available in the field at the priority date, presented with the prior knowledge or prior use relied upon. It asks whether to that person or team the alleged inventive step would be obvious and would be recognised, without bringing to bear any inventiveness, as something that could be done or is at least worth trying.66
In determining the issue of obviousness, a four step analysis is adopted.67 First, the court identifies the inventive concept embodied in the patent. Next, the court will assume the mantle of the skilled in the art but unimaginative addressee, and will impute to him the common general knowledge in the relevant art at the priority date. The skilled addressee may be a team with differing scientific knowledge.68 The court should then identify what, if any, differences exist between the matters cited as being published or used and the alleged invention. Finally, the court has to decide whether, viewed without any knowledge of the alleged invention, those differences constitute steps which would have been obvious to the skilled person, or whether they require any degree of invention.69 If any embodiment within the claim is obvious, the claim is invalid.70 The court must be careful to avoid using the benefit of hindsight to find obvious that which at the relevant time was not obvious: 'Ex postfacto analysis of invention is unfair to the inventors and, in my opinion, it is not countenanced by English patent law'.71 The primary evidence — opinions of expert witnesses — will be of assistance to a court in determining whether or not the relevant step would have been obvious to a person skilled in the art.72 Evidence of the commercial success of the invention may suggest that it has fulfilled a 'long felt want' .73 Such evidence may support a finding that the invention was not obvious, but 'it is no more than an aid in assessing the primary evidence'.74