FCA 1211
- In a decision handed down by Justice Jagot on 8 November 2010, applications by Sigma, Alphapharm and Generic Health for revocation of Australian Patent No 2003259586 were dismissed. Justice Jagot further granted Wyeth’s cross-claims for infringement.
- Although the decision has been appealed by Sigma, Justice Jagot’s reasoning is instructive for patent litigants, particularly with respect to:
- the construction of patents, and
- the compilation of expert evidence in relation to patent revocation matters.
Wyeth is the patentee of the ‘extended release formulation’ patent granted on 11 May 2007, which relates to the compound venlafaxine hydrochloride (VH) (Patent). Wyeth’s subsidiary, Wyeth Australia Pty Limited (together, Wyeth), has, since February 1999, sold an extended release dosage of VH in Australia which is used as an anti-depressant. Previously, it sold an immediate release dosage form of VH which had a number of side effects in patients including nausea and vomiting.
The Patent claims a priority date of 25 March 1996 based on a previously filed US patent application and contains 28 claims, each of which essentially involve one or more of the following four principles as set out by Justice Jagot at :
- administering orally to a patient in need of VH a single daily dosing formulation of VH
- that provides a therapeutic blood plasma concentration of VH over a 24-hour period
- that provides a peak blood plasma level of VH in from about 4–8 hours after administration, and
- with a peak blood plasma level of no more than 150 ng/ml.
Each of the applicants, Sigma Pharmaceuticals (Australia) Pty Limited’s (Sigma), Alphapharm Pty Limited (Alphapharm) and Generic Health Pty Limited (Generic Health) have registered extended release formulations of VH in Australia.
Wyeth contended that the applicants’ use of their extended release formulations of VH in Australia infringe certain claims of the Patent. The applicants denied infringement and contended that the Patent was invalid.
The applicants attacked validity of the Patent on the following grounds:
- the invention lacked novelty by reason of a deferred priority date. This argument was based on the fact that amendments were made to the patent specification and claims after the filing of the complete specification and prior to acceptance. On this basis, the applicants argued that Wyeth was not entitled to claim a priority date before 20 December 2006. By that time, Wyeth was already selling its extended release formulation of VH. Alphapharm and Generic Health, but not Sigma, further argued that the invention was anticipated by another patent known as the Alza or Edgren patent
- the claims were not fairly based on the disclosure in the priority document or the specifications
- the specification was insufficient to describe the invention fully
- the claims lacked clarity and therefore do not claim an invention
- there was a lack of an inventive step
- the amended form of the Patent was obtained by Wyeth making false representations, which materially contributed to the grant, and
- Wyeth was not entitled to the Patent.
The priority date and fair basing
Justice Jagot upheld the 25 March 1996 priority date of the Patent on the basis that the claims of the patent were in substance disclosed or fairly based on the US priority document filed on that date. Her Honour found that any amendments made in December 2006 did not affect that disclosure.
The relevant question in determining whether the claims were fairly based on the priority document was whether there had been a real and reasonably clear disclosure of the claims of the Patent in the US priority document. Justice Jagot rejected the applicants’ approach to construing the patent, on the basis that it:
1.gave undue weight to the amendments made to the patent application December 2006, by using these amendments as the relevant starting point for resolution of questions of construction and disclosure, and
2.erroneously construed the invention as a formulation rather than a method.
These errors of construction played into the applicants’ argument in relation to ‘external’ fair basing (that is, whether the claims were fairly based on matters disclosed in the priority document). For example, the applicants argued that the original specification and the US priority document were confined to a particular formulation of VH and that this did not support the Patent being ‘extended’ to a method of treatment not confined to the particular formulation identified in the US priority document. However Justice Jagot agreed with Wyeth’s submissions that the priority document disclosed two inventions—a formulation and a method—and that, when read as a whole, the claims of the Patent were fairly based on that priority document.
Alphapharm (and to an extent Generic Health), also contended that the international Alza or Edgren patent anticipated at least some of the claims of the Patent. In particular, Alphapharm contended that if example 2 of the Alza patent was followed, there would inevitably be a therapeutic blood plasma concentration profile for VH over a 24-hour period which fell within the scope of the claims of the Patent. However, Justice Jagot found that this argument was not made out on the basis that:
- the constituents were different (it was not enough that the constituents were proportionally the same based on percentage weight)
- the release rates were different, and
- the manufacturing procedures in the Alza patent were highly prescriptive and it was not clear on the evidence that the Wyeth dosage form was manufactured in accordance with those specific procedures.
Section 40 issues
The applicants’ five arguments on fair basis were all dismissed by Justice Jagot when assessed in light of the proper enquiry—that is, whether the claim ‘travels beyond’ the matter disclosed in the specification.
As on the priority date issue, Her Honour believed the applicants had embarked on an erroneous characterisation of the invention (as a formulation rather than a method) and, in connection with this, a flawed argument that the ‘consistory style statements’ in the specification broadened the disclosure. Her Honour stated that whether the consistory statements are mere assumptions or are supported by the specification as a whole is a matter of construction and found in this instance that the consistory style statements supported the specification.
One of the grounds argued by the applicants was that the disclosure included an express statement that it had been impossible to produce extended release tablets using a particular technology (hydrogel technology). In this regard, Sigma argued that the patentee could not claim a monopoly for something that is was unable to produce. However Justice Jagot referred to the principle in Lockwood No 11 that:
When a combination claim states an invention which gives an old result by a new means, the monopoly is limited, at any rate prima facie, to the new means. But when by a new application of principle the inventor has obtained a new result or thing, even when it be done by a combination, he may claim all the alternative means by which the thing or result may be achieved.
Again, it was key that the invention disclosed a method rather than a formulation.
Justice Jagot dismissed the applicants’ submissions that the principles in Lockwood No 1 and Kimberley-Clark2 regarding sufficiency should be confined to product claims. Relying on expert evidence, Her Honour found that the skilled addressee would be able to produce an embodiment within the claims based on the description in the specification.
Lack of clarity
The applicants contended that the claims are not clear insofar as they refer to a ‘therapeutic blood plasma concentration’. However an examination of the expert evidence relating to the knowledge of the skilled addressee as at the priority date indicated that the phrase did not lack clarity. Her Honour further found that it was not circular to define a claim by reference to a result achieved.
Her Honour found that it would not have been obvious to the skilled addressee that the solution to the ‘problem’ of the immediate release formulation was a method of treatment involving the single daily dosing formulation. Her Honour restated the principle that it is:
- erroneous to characterise as obvious the variation of all parameters or the trying of all choices until one proves successful, where the prior art did not point to it
- erroneous to characterise as obvious the exploration of a new technology where the prior art gave no more than general guidance, and
- not acceptable to start from the invention when determining whether it was obvious.
Her Honour’s findings have implications for the gathering of evidence in patent revocation proceedings and formed another point of difficulty for the applicants in this case.
Firstly, the applicants had approached the problem having assumed that the invention related to a formulation rather than a method, and their expert evidence reflected this erroneous assumption.
Secondly, much of the evidence given by certain experts called by the applicants was affected by circumstances that were material to their conclusions but would not have existed at the priority date. In addition, some of the experts knew that the matter related to a disputed patent and were, therefore, presumably aware that at least one party had successfully prepared an extended release formulation of VH at the priority date. In other instances, the experts were instructed by the applicants to assume that they had been instructed to prepare an extended release formulation of VH, which, as Wyeth submitted, ‘assumes away part of the invention’ [at 330]. All of these factors raised a number of problematic hindsight issues.
Thirdly, the applicants relied to a certain extent on the problem-solution approach, which, as Her Honour stated, was not sufficient of itself, in the circumstances, to answer the question of whether the method claimed in the patent was obvious when compared with the prior art base. Her Honour referred to the Full Court’s comments in Apotex3, that the problem-solution approach ‘may not be appropriate or sufficient where, for example, no skilled person in the art had thought of a general idea or general method of solving a known difficulty with respect to a known product or where the appreciation that there was a problem with a known product was itself part of the inventive concept’ and the statement in Lockwood No 24 that ‘ingenuity may lie in an idea for overcoming a practical difficulty in circumstances where a difficulty with a product consisting of a known set of integers is common general knowledge.’
False suggestions and misrepresentations
The applicants relied on five alleged misrepresentations to argue that the Patent should be revoked under section 138(3)(d) or (e) of the Patents Act 1990 (Cth). These alleged representations were contained in the specification and in other material provided to the Commissioner and went to:
1.that it was impossible to make an extended release formulation of VH using hydrogel tablet technology
2.that it was not expected that a single daily dosing formulation of VH for use in the methods of the invention could be achieved
3.that the controlled release dosage form described in the Alza patent would not produce a peak blood plasma level of between 4–8 hours
4.that a certain individual (Ms Sherman) was the sole inventor of the invention when, in fact, there were additional inventors, and
5.that the invention reduces the level of nausea and incidence of vomiting when compared to the immediate release form.
Justice Jagot dismissed each of the arguments in turn. In relation to the first two alleged misrepresentations, Her Honour found that, when read in context, the skilled addressee would have understood the references to refer not to utter impossibility but rather to the inventor’s position. The third alleged misrepresentation was similarly not found to be false or misleading, as a matter of construction and when read in context. In relation to the sole inventor ground, Her Honour found that as a matter of fact, there were additional inventors that had not been nominated in the application. However the applicants failed to demonstrate that this omission was material to the grant of the patent. The final alleged misrepresentation (asserted by Generic Heath only) was dismissed on the basis that Generic Health had not adduced evidence in support of the contention and the expert evidence supported the fact that there had been an amelioration of the overall side effects.
The applicants contended that Wyeth was not an eligible person. In circumstances where Wyeth derived title to the invention from inventors who were employed by its subsidiary, and where those inventors had executed agreements to transfer their rights to Wyeth, the onus upon the applicants to prove their contention was a difficult onus to discharge. Her Honour found that the applicants had not proved lack of entitlement in the face of evidence that an assignment of all rights in connection to the invention had been made in favour of Wyeth.
In a separate judgment (Sigma Pharmaceuticals (Australia) Pty Ltd v Wyeth (No 2)  FCA 1212), Justice Jagot addressed issues of confidentiality, the making of final orders and costs. The usual orders as to costs were made and Her Honour ordered that any appeal be granted expedition.