Pharmaceutical formulation patent not obvious, but also not inventive – judge in effect extends the

Pharmaceutical formulation patent not obvious, but also not inventive – judge in effect extends the

In Aktiebolaget Hässle and Astra Pharmaceuticals Pty Limited v Alphapharm Pty Limited, May 1999, a single judge of the Federal Court found a patent filed under the Patents Act 1952 claiming an omeprazole formulation invalid on the basis of a lack of inventive step. The judgment is somewhat surprising given that evidence provided by the patentee demonstrated that it took a team of highly skilled scientists some four years to solve the problem of how to provide an orally bioavailable formulation of omeprazole (a compound unstable in the presence of moisture and rapidly degraded in acid or neutral solution). The decision is particularly surprising in view of the fact that lack of inventive step was judged under the old Patents Act under which the relevant prior art is limited (by case law) to information which is part of the common general knowledge in the art in Australia at the priority date.

The patented omeprazole formulation for inhibition of gastric acid secretion is marketed in Australia under the trade mark "Losec", and at the time of the case was the second highest selling pharmaceutical on the Australian market. The proceedings commenced following a claim by the patentee, Aktiengesellschaft Hässle, and its Australian exclusive licensee Astra Pharmaceuticals Pty Ltd (both hereafter referred to as "Astra") that the proposed launch on the Australian market by Alphapharm Pty Ltd ("Alphapharm") of a generic omeprazole formulation would infringe Astra's patent. Alphapharm cross-claimed for revocation of the patent. Although evidence in the revocation proceedings was led on a number of grounds, it was the ground of inventive step upon which the case turned. The patent was found valid on each of the other grounds and the judge, Lehane J, went on to say that had the patent been held to be valid it would have been infringed by Alphapharm's proposed activities.

Both parties provided detailed submissions on the steps that would be taken by a skilled pharmaceutical formulator in attempting to solve the formulation problems associated with omeprazole. Naturally, this evidence was conflicting in nature. The most compelling of the evidence was (i) the use by Alphapharm of an expert to whom questions were posed regarding how to deal with the problems associated with omeprazole formulation (he was not provided with copies of the Astra patent or other papers relevant to the legal proceedings, in order to prevent the allegation that his solution to the problem was tainted by a hindsight reconstruction); and (ii) Astra's detailed evidence of the process associated with the development of the patented formulation, the numerous problems encountered along the way and the fact that this development process took a team of scientists at least four years to complete.

The Alphapharm expert (supposedly a hypothetical skilled but unimaginative pharmaceutical formulator) made a number of suggestions about the path down which a skilled pharmaceutical formulator would travel in order to solve the problem, which did have certain similarities to the solution achieved by Astra's scientists. The problem with this approach, however, was that the Alphapharm expert provided a number of potential research avenues which could be followed, and appeared to only get close to the Astra solution by following some prompting from Alphapharm's solicitors. Even then his final solution was not exactly as outlined in the patent in suit.

In support of his conclusion on the issue of obviousness Lehane J made the following striking comment, "Certainly, considered at the commencement of a hypothetical attempt, immediately before the priority date, to formulate omeprazole, the combination claimed in the patent was not obvious. The question is whether the hypothetical, not particularly imaginative skilled formulator, equipped with common general knowledge and embarking on the task at that time, would be likely to have arrived at the combination by taking routine steps which such a formulator would take for the purpose of formulating a drug". Later his Honour said, "I have no difficulty with the proposition that a formulator asked, in April 1986, to formulate omeprazole would have done a literature search at least in order to discover what learning there was about omeprazole itself and it characteristics" Through these statements Lehane J appears to acknowledge non-obviousness under the accepted test for inventive step, at the same time as finding the combination obvious under a new test that effectively extends the range of materials relevant to an inventive step analysis beyond what is normally understood as the "common general knowledge". "[R]outine steps which such a formulator would take for the purposes of formulating a drug" can evidently include the steps of conducting a literature search, reviewing documents located in the search and making assessments based on the teaching in such documents as to how the problem at hand may be solved; steps allowing the inclusion of material certainly outside what would normally be understood as "common general knowledge" information.

It is believed that the analysis of Lehane J on the law of inventive step in Australia may effectively lead to the possibility of mosaicing of prior art documents in making an assessment of inventive step under the Patents Act 1952. It may also lead to the situation where patents or patent applications filed under the Patents Act 1952 and directed to inventions achieved by a series of incremental steps, each involving an intellectual input and elements of unpredictability (as opposed to a single inventive leap), could be vulnerable to allegations of lack of inventive step. This is despite the fact that an assessment of the problem to be solved at the priority date, in light of the common general knowledge in the field, would lead to a finding of non-obviousness of the "invention" concerned by a skilled person. It is even conceivable that the expanded concept of what constitutes the "common general knowledge" adopted by Lehane J could subsequently be drawn upon in assessments of inventive step under the Patents Act 1990, which already allows the combining of teachings in any single document with the common general knowledge in the field.

The decision has been appealed to the Full Court of the Federal Court.