Sigma Pharmaceuticals (Australia) Pty Ltd v Wyeth

The Amended Patent 142 The Amended Patent is also entitled "Extended Release Formulation" and, except for some minor and immaterial differences, the background to the invention is precisely the same as that contained in the Priority Document. However, substantial amendments have been made to the section entitled "Brief Description of the Invention". The brief description states: In accordance with this invention, there is provided a method for providing a therapeutic blood plasma concentration of venlafaxine over a 24 hour period which comprises administering orally to a patient in need of venlafaxine a single daily dosing formulation of venlafaxine hydrochloride that provides a peak blood plasma level of venlafaxine in from about 4 to 8 hours after administration. This statement is followed by a series of references to various embodiments of the invention that are in the nature of consistory clauses the language of which mirrors subsequent claims. These are followed by a description of what are referred to as examples of the invention. The specification states: In an example of the invention, the formulation of venlafaxine hydrochloride is an extended release formulation that is administered as a single daily dosing formulation. In one embodiment, the single daily dosing formulation when used in the method of the invention will provide a peak blood plasma level of venlafaxine from 5-8 hours after administration, most preferably, about 6 hours after administration. In one embodiment, the venlafaxine hydrochloride formulation for use in the methods of this invention is comprised of venlafaxine hydrochloride … in admixture with microcrystalline cellulose and hydroxypropylmethylcellulose. As an example, the extended release formulations are formed as coated beads or spheroids. In one embodiment, the drug containing formulation is coated with a mixture of ethyl cellulose and hydroxypropylmethylcellulose to provide the desired level of coating ... 143 The 2006 Amendments introduced new claims falling into two groups. The first, claims 1 to 17 and claim 27 (insofar as it is dependent on claims 1 to 17), are method of treatment claims that are not limited to methods utilising a formulation made from spheroid core comprising venlafaxine hydrochloride, MC and HPMC. The second, claims 18 to 28, are confined to treatments utilising a formulation made from spheroid core comprising venlafaxine hydrochloride, MC and HPMC. 144 The statements in the Priority Document concerning what was "completely unexpected" and what was "impossible to achieve" also appear in the Amended Patent except that in the Amended Patent the first of these statements refers to "a single daily dosing formulation" instead of "an extended release formulation". 145 Claims 1 to 4 are as follows: 1. A method for providing a therapeutic blood plasma concentration of venlafaxine over a 24 hour period which comprises administering orally to a patient in need of venlafaxine a single daily dosing formulation of venlafaxine hydrochloride that provides a peak blood plasma level of venlafaxine in from about 4 to 8 hours after administration. 2. A method for moderating the plural blood plasma peaks and valleys attending the pharmacokinetic utilization of multiple daily dosing with venlafaxine hydrochloride, which comprises administering orally to a patient in need of venlafaxine a single daily dosing formulation of venlafaxine hydrochloride that provides a therapeutic blood plasma concentration of venlafaxine over a 24 hour period with a peak blood plasma level of venlafaxine in from about 4 to 8 hours after administration. 3. A method of reducing the level of nausea and the incidence of emesis in a patient in need of venlafaxine which comprises administering orally to said patient, a single daily dosing formulation of venlafaxine hydrochloride that provides a therapeutic blood plasma concentration of venlafaxine over a 24 hour period and a peak blood plasma level of venlafaxine in from about 4 to 8 hours after administration. 4. A method for treating depression in a patient in need of such treatment, which comprises administering orally to said patient, a single daily dosing formulation of venlafaxine hydrochloride that provides a therapeutic blood plasma concentration of venlafaxine over a 24 hour period with a peak blood plasma level of venlafaxine in from about 4 to 8 hours after administration. 146 Claims 5 to 8 mirror the language of claims 1 to 4 except that, rather than referring to "a peak blood plasma level of venlafaxine in from about 4 to 8 hours after administration", each of these claims refers to "a peak blood plasma level of no more than 150 ng/ml". Claim 9 is dependent upon claims 1 to 4 and limits the blood plasma level of venlafaxine for the purposes of those claims to 150 ng/ml. Claim 10 is dependent on claims 5 to 7. It provides that the blood plasma level of venlafaxine for the purposes of claim 5 to 7 will be achieved in from about 4 to 8 hours. Claims 11 to 14 also mirror claims 1 to 4 but rather than specifying peak blood plasma levels they instead specify various dissolution profiles. Claims 15 to 17 are dependent claims about which I need not say more. Claim 18 is not in issue but is worthy of mention in that it is another dependent claim which confines the method of treatment the subject of the preceding claims to the use of a formulation comprising spheroids made of venlafaxine hydrochloride, MC and HPMC coated with EC and HPMC. Claim 27, which is in issue, is to "[a] method according to any one of the preceding claims wherein the formulation is an encapsulated formulation."

Priority Date/External Fair Basis 147 Each of the relevant claims, being claims 1 to 17 and 27 of the Amended Patent, was introduced by the 2006 Amendments. The appellants submitted that the primary judge erred in failing to find that the relevant claims were not fairly based on the Priority Document. The respondents concede that if that submission is accepted then it follows that the appeals must be allowed and that each of the relevant claims must be revoked. Before considering this submission further it is necessary to refer to the statutory context in which it arises. 148 The Amended Patent is the result of a divisional application made under s 79B(1) upon the Parent Application which was itself a divisional application founded upon the Grandparent Application. This is of significance because the Regulations make specific provision for determining the priority date of a claim based upon matter disclosed in a specification filed under s 79B(1) of the Act. Section 79B(1) provides: (1) If a complete patent application for a patent is made (but has not lapsed or been refused or withdrawn), the applicant may, in accordance with the regulations, make a further complete application for a patent for an invention: (a) disclosed in the specification filed in respect of the first mentioned application; and (b) where the first mentioned application is for a standard patent and at least 3 months have elapsed since the publication of a notice of acceptance of the relevant patent request and specification in the Official Journal - falling within the scope of the claims of the accepted specification. 149 Each of the claims of the Amended Patent must have its own priority date determined in accordance with the relevant provisions of the Act and the Regulations. To that end there are two relevant sets of provisions. The first set relates to the priority dates of claims generally including, in particular, the priority dates of claims of a patent resulting from an application under s 79B(1) of the Act. The second relates to the priority date of claims to matter that was in substance disclosed as a result of an amendment to a specification. 150 The position with respect to priority dates generally is dealt with in s 43(2) of the Act. Relevantly, the priority date of a claim is the date of the filing of the specification or, where the Regulations provide for the determination of a different date, the date determined under the Regulations. Regulation 3.12 relevantly provides: (1) Subject to regulations 3.13 and 3.14 and subregulation (2), the priority date of a claim of a specification is the earliest of the following dates: (a) the date of filing of the specification; (b) if the claim is fairly based on matter disclosed in 1 or more priority documents, the date of filing the priority document in which the matter was first disclosed; (c) if the specification is a complete specification filed in respect of a divisional application under section 79B of the Act and the claim is fairly based on matter disclosed in the specification referred to in paragraph 79B (1) (a) of the Act - the date mentioned in subregulation (2C); … (2) For the purposes of paragraph (1) (b): (a) if the application that relates to the specification containing the claim is a complete application - a provisional application that is associated with that complete application in accordance with section 38 of the Act is a priority document; and (b) if the application that relates to the specification containing the claim is a Convention application, a document of any of the following kinds is a priority document: (i) a basic application that is related to the Convention application; (ii) a specification, or another document filed in respect of, and at the same time as, a basic application that is related to that Convention application; or (iii) a specification in respect of a basic application that is related to that Convention application, being a specification that was filed after the basic application was made; … … (2C) The date for a specification to which paragraph 3.12 (1) (c) applies is the date that would have been the priority date of the claim if it had been included in the specification referred to in paragraph 79B (1) (a) of the Act. … 151 The relevant effect of these provisions is as follows. Subject to reg 3.14, if a claim of the Amended Patent is fairly based on matter disclosed in the Parent Application then the claim will have the priority date to which it would have been entitled if it had been included in the Parent Application. However, since the Parent Application is itself a divisional application based upon the Grandparent Application, the priority date of the claim also depends upon what priority date it would have had it if had been included in the Grandparent Application. The Grandparent Application, which was not a divisional application, claimed priority of 25 March 1996 - the earliest available priority date - based upon the filing of the Priority Document. So if a claim of the Amended Patent is to have the earliest available priority date, it must be fairly based on the matter disclosed in each of the Parent Application, the Grandparent Application and the Priority Document. 152 As to amendment or, more specifically, any disclosure by amendment, s 114(1) of the Act provides that where a claim of a complete specification claims matter that was in substance disclosed as a result of amending the specification, the priority date of the claim must be determined under the Regulations. The regulation made for that purpose is reg 3.14 which relevantly provides that the priority date of a claim to which s 114(1) applies is the date of the filing of the proposed statement of amendments which resulted in the disclosure occasioned by the amendment to the specification. As I have mentioned, reg 3.12 is expressed to apply subject to reg 3.14. So the logical starting point in determining the priority date of the claims of the Amended Patent is therefore s 114(1) and reg 3.14. 153 Section 114 and reg 3.14 are directed to a consideration of the matter disclosed by the specification as it stood immediately prior to the relevant amendment. This has significance in the present case because the amendments made not only introduced new matter but also excluded existing matter. In fact, the matter excluded included a great deal of matter said to be incorporated by reference including the entirety of the Parent Application and the Grandparent Application. Thus, one way or another, all of the disclosures of the Priority Document were already present at the time of the 2006 amendments. The question is whether these disclosures provide a sufficient basis for the new claims introduced by the 2006 Amendments or whether such claims are for matter that was in substance disclosed as a result of the 2006 Amendments. The priority date of any claim to matter that was in substance disclosed as a result of the 2006 Amendments will be 20 December 2006 which is, as is conceded by the respondents, fatal to validity. 154 Subject to a number of minor differences not relevant for present purposes, prior to its amendment by the 2006 Amendments the Amended Patent was in virtually identical terms to the Priority Document. Hence, the question arising under s 114 and reg 3.14 may be addressed, in a practical sense, by asking whether the new claims introduced by the 2006 Amendments were to matter not disclosed in the Priority Document. 155 Wyeth relied upon the primary judge's analysis of the Priority Document. Her Honour identified the relevant question as being whether there was a real and reasonably clear disclosure of the claims of the Amended Patent in the Priority Document. In support of that approach the primary judge cited Lockwood Security Products Pty Limited v Doric Products Pty Ltd (No 1) (2004) 217 CLR 274 at [69]. In that case the High Court was concerned with a question of internal fair basis, that is to say, whether the claims of the patent in issue were fairly based on the matter described in the specification. Nevertheless, the same test is in my view applicable here, the question being whether there was a real and reasonably clear disclosure of the invention claimed in the Amended Patent in the Priority Document. However, there was a debate before us as to what role, if any, claims 9 or 10 of the Priority Document should play in answering that question. 156 The primary judge found that when read as a whole, the Priority Document disclosed two different inventions, the first being an encapsulated formulation, and the second being, in her Honour's words, "a method for obtaining a certain drug to plasma relationship over time yielding a tighter plasma therapeutic range control than multiple daily dosing, eliminating the sharp peaks and troughs in blood plasma levels induced by multiple daily dosing and thereby reducing the level of nausea and incidence of emesis that attend multiple daily dosing." Having referred to Wyeth's submissions, her Honour said (at para [165]): This is not a case where claims 9 and 10 are unrelated to the disclosure in the US priority document. The US priority document discloses two inventions. The first is an encapsulated formulation. The second is a method for obtaining a certain drug to plasma relationship over time yielding a "tighter plasma therapeutic range control" than multiple daily dosing, eliminating the sharp peaks and troughs in blood plasma levels induced by multiple daily dosing and thereby reducing the level of nausea and incidence of emesis that attend multiple daily dosing. The method involves providing in a single dose a therapeutic blood serum level of venlafaxine hydrochloride over a 24 hour period, with plasma levels rising for between about five to eight hours after administration of the formulation (optimally about six hours) and then beginning to fall through a protracted substantially linear decrease from the peak plasma level whilst maintaining a threshold therapeutic level over the entire twenty four hour period. The references to the inventor's failed efforts to prepare a hydrogel tablet formulation and to an encapsulated formulation in claims 9 and 10 do not eliminate the disclosure in the US priority document of this method of treatment. When the US priority document is read as a whole, the method disclosed is not confined to the particular encapsulated formulations (or embodiments or examples) which are also disclosed. The claims of the patent are in substance disclosed in or fairly based on the US priority document. The amendments made in December 2006 cannot and do not alter this fact of disclosure. The role of claims 9 and 10 of the Priority Document was not addressed by the primary judge because, as I read her Honour's reasons, she considered that the body of the specification provided the necessary disclosure. Indeed, on her Honour's interpretation of the Priority Document, the disclosure went beyond what was claimed in claims 9 and 10, at least in the sense that those claims are, as her Honour noted, limited to methods of treatment involving the use of "encapsulated" formulations containing venlafaxine hydrochloride. 157 I do not agree that the invention as defined by various claims of the Amended Patent was the subject of a real or reasonably clear disclosure in the Priority Document. Numerous claims introduced by the 2006 Amendments travel beyond the disclosure of the Priority Document. In my view it is quite apparent that none of the claims for methods of treatment which involve the use of formulations that are not encapsulated are properly based upon any real or reasonably clear disclosure in the Priority Document. Although there is a dependent claim which incorporates a limitation of this kind, the primary judge upheld the validity of all the claims of the Amended Patent including those which did not incorporate any such limitation. With due respect to the primary judge, I consider that she has construed the Priority Document too broadly. 158 By the time the reader of the Priority Document gets to the claims 9 and 10, there is already much to indicate that the invention disclosed is limited to a particular formulation and a method of treatment involving the administration of that formulation. 159 First, the discussion of the background to the invention explains the context of the invention. In particular it identifies various problems associated with venlafaxine hydrochloride in the compressed tablet formulation presently administered to adults. The discussion raises the question (at least by clear implication) of how to provide those in need of venlafaxine hydrochloride with a single daily dosing of the drug in lieu of two or three times a day dosing so as to avoid the pronounced fluctuations in blood plasma concentrations and the common side effects associated with a multiple dosing regime. The solution proposed is a new formulation the use of which is said to eliminate or reduce both the fluctuations in blood plasma concentrations and the side effects associated with the multiple dosing regime. 160 Secondly, there is the repeated reference to "formulations of this invention" occurring throughout the Priority Document. The brief description of the invention describes an encapsulated formulation. The whole of the brief description is confined to production and administration of that formulation. So too is the detailed description of the invention. It describes the invention as being made from a mixture including MC and HPMC which is formed into spheroids coated with CE and more HPMC. While various options are discussed, there is no suggestion that the formulation might not be made from spheroids formed with a mixture including MC and HPMC. On the contrary, the whole of the description suggests that these are essential features of the formulation of the invention. 161 Thirdly, nowhere in the detailed description of the invention is there any mention of the possibility that the methods disclosed might include those which involve the administration of a formulation different to "the formulation of this invention". In saying this I am not suggesting that the disclosure of the Priority Document is confined to a specific formulation corresponding in every detail to the embodiments described in the detailed description. The Priority Document makes clear that various equivalents may be substituted for some of the ingredients used in the particular examples that are described. But nowhere is it stated or implied that the methods of the invention might be employed through the use of a completely different formulation such as might be produced using hydrogel tablet technology. 162 None of this is surprising considering the background to the invention as explained in the section of the Priority Document devoted to that topic and the subsequent account of the problems experienced by the inventors when attempting to use hydrogel tablet technology. It is represented that the inventors moved to an encapsulated formulation using film coated spheroids because the use of hydrogel tablet technology was not feasible. 163 Sigma submitted that in considering the scope of the disclosure of the Priority Document claims 9 and 10 should be disregarded because, as I understood the submission, they were not fairly based. But the question before us does not depend on whether or not those claims are fairly based. There is no reason why they or any other claims of the Priority Document should not be considered for the purpose of ascertaining what is disclosed by the Priority Document when read as a whole. Claims 9 and 10 are part of an entire document said to make a particular disclosure. However, read in context, those claims refer to methods of achieving certain concentrations and profiles which employ "an encapsulated extended release formulation" which I take to be the formulation of the invention as more fully described in the specification. 164 The primary judge did not place any reliance upon claims 9 and 10 of the Priority Document but remarked that the references in those claims to an encapsulated formulation "do not alter the fact that a method is disclosed." However, when the Priority Document is read as a whole, the method disclosed is limited to one which makes use of an encapsulated formulation. The language of claims 9 and 10 of the Priority Document is consistent with this particular limitation being an essential feature of the invention described. 165 In my opinion the invention disclosed by the Priority Document is an encapsulated extended release formulation of venlafaxine hydrochloride which can be used to eliminate the sharp peaks and troughs in blood plasma levels associated with multiple daily dosing regimes and some of their common side effects. What is described in the Priority Document is essentially a formulation, with the methods of treatment described being confined to those which make use of that formulation. The formulation and the method of treatment are not different inventions but different forms or aspects of the same invention. 166 Thus, in the brief description of the invention, reference is made to "the use aspect of this invention" suggesting, consistently with my reading of the whole of the description, that there is in substance a single invention disclosed in the Priority Document consisting of an encapsulated formulation which may be used in the treatment of depression. There is no suggestion in the description of the invention or the claims in the Priority Document that any method of treatment the subject of the invention might involve the use of a non-encapsulated formulation. 167 None of claims 1 to 17 of the Amended Patent is confined to a method of treatment involving the administration of encapsulated formulations. Accordingly, I do not think those claims are fairly based on the Priority Document. Each of claims 1 to 17 is therefore invalid. 168 Claim 27 is dependent on (inter alia) each of claims 1 to 17 and introduces an additional requirement that the formulation referred to in each such claim be encapsulated. However, claim 27, when read in conjunction with any of claims 1 to 17, is not confined to a formulation made from spheroids formed with a mixture including MC and HPMC. Again, I do not think that claim 27, when read with any of claims 1 to 17, is fairly based on the Priority Document. Each of the methods of treatment described in the Priority Document involves the administration of what is referred to throughout as "the formulation of the invention" or "the film-coated spheroid compositions of this invention" comprising, among other things, spheroids made from a mixture including venlafaxine hydrochloride MC and HPMC. It follows that claim 27, insofar as it is dependent on any of claims 1 to 17, is not fairly based.

Internal Fair Basis 169 A consistory clause may provide a fair basis for a claim which mirrors its language but not if there are other matters disclosed in the specification which show that the invention is narrower than the consistory clause suggests. The High Court said in Doric at [99]: … the correct position is that a claim based on what has been cast in the form of a consistory clause is not fairly based if other parts of the matter in the specification show that the invention is narrower than that consistory clause. The inquiry is into what the body of the specification read as a whole discloses as the invention [Welch Perrin & Co Pty Ltd v Worrel (1961) 106 CLR 588 at 612-613]. An assertion by the inventor in a consistory clause of that of which the invention consists does not compel the conclusion by the court that the claims are fairly based nor is the assertion determinative of the identity of the invention. The consistory clause is to be considered by the court with the rest of the specification. 170 Wyeth relied upon the consistory clauses introduced by the 2006 Amendments as providing fair basis for claims 1 to 17 and claim 27. In my opinion, the consistory clauses do not do so because they do not reflect the description of the invention contained in the specification when read as a whole. 171 I agree with Wyeth that claims 1 to 17 of the Amended Patent cover methods of treatment that involve the administration of formulations containing venlafaxine hydrochloride produced through the use of hydrogel tablet technology. I do not think it is possible to read those claims down so to exclude from their scope methods of treatment that utilise such formulations. This is significant because, in my view, the specification contains what is tantamount to a disclaimer of hydrogel tablet technology. In particular, it makes clear that the advantages of the invention cannot be obtained by using hydrogel tablet technology and that the addressee wishing to prepare an extended release formulation of venlafaxine hydrochloride for administration to those in need of that drug should not attempt to use that technology for that purpose. 172 Dr Marshall and Professor Charman agreed that, as at the priority date, the skilled addressee would not have considered it impossible to achieve an extended release formulation of venlafaxine hydrochloride. But the fact that they might disagree with what is said in the specification is not relevant to its proper construction. 173 In my view, the specification, read as a whole, makes clear that the invention described does not encompass the use of any formulation of venlafaxine hydrochloride produced by hydrogel tablet technology. Since claims 1 to 17 of the Amended Patent encompass methods of treatment that utilise formulations produced by hydrogel tablet technology, each of claims 1 to 17 is too broad and not fairly based upon matter described in the specification. Accordingly, claims 1 to 17 are also invalid on the ground that they do not comply with the requirements of s 40(3) of the Act. 174 The position with respect to claim 27, in so far as it is dependent on claims 1 to 17, is slightly different because it does not include within its scope methods of treatment that utilise formulations produced by hydrogel tablet technology. 175 Since it is the Amended Patent which must be construed for the purpose of determining any questions of internal fair basis, one would ordinarily undertake that exercise without regard to the terms of any priority document. But the position here is somewhat unusual in that the entire disclosure of the Parent Application and the Grandparent Application is incorporated by reference. Each of these reproduce the whole of the Priority Document. What is even more unusual about the way in which these prior disclosures have been incorporated is that the reader is not given any instruction or guidance as to what use he or she is expected to make of them. 176 I agree with Wyeth that the Amended Patent should be read as though these prior disclosures were set out in their entirety. When this is done, it is in my opinion apparent that the invention described is for a method of treatment calling for the administration of an encapsulated formulation of venlafaxine hydrochloride comprising film coated spheroid compositions made from a mixture of venlafaxine hydrochloride, MC and HPMC. 177 There is no doubt that the consistory clauses describe the methods of the invention much more broadly than this. However, by the time the reader gets to the consistory clauses a great deal of information has already been imparted to show that the methods of the invention are as I have described. 178 Wyeth submitted that the specification disclosed a method for achieving a specified plasma concentration profile and drug dissolution profile that was found to be efficacious, but with reduced nausea and vomiting. It submitted that while those plasma concentration and drug dissolution profiles may be achieved by the administration of the formulations described in the specification, they might just as well be achieved by the use of different formulations of venlafaxine hydrochloride. Wyeth submitted that by achieving the specified profiles with reduced nausea and vomiting the inventors had arrived at a new result by a new application of principle thereby entitling them to claim all the alternative means by which that result could be achieved: see Shave v H V McKay Massey Harris Pty Ltd (1935) 52 CLR 701 at 709 per Rich, Dixon, Evatt and McTiernan JJ. 179 Wyeth's arguments were substantially based upon evidence given by Professor Charman as to his understanding of the Amended Patent. He said that the Amended Patent "teaches that a unique plasma profile of venlafaxine leads to the reported beneficial clinical profile (including improvements in side effects)". In support of this interpretation of the specification he pointed to the profiles reported in tables 2 and 3 of the Amended Patent. His evidence was relied upon by Wyeth and by the primary judge in support of the conclusion that the method taught by the Amended Patent is not limited to the use of any particular venlafaxine hydrochloride formulation. 180 The profiles reported in tables 2 and 3 of the specification are the profiles achieved using what are referred to as the film coated spheroid formulations of the invention. While tables 2 and 3 describe profiles achieved using those formulations, they do not disclose anything at all about the profiles that might be achieved using other formulations. The evidence established that it would have been understood by the skilled addressee as at 25 March 1996 that it was not possible to predict what profile any other formulation of venlafaxine hydrochloride would have based upon anything contained in the Amended Patent. So I do not think tables 2 and 3 provide any basis for inferring that the methods of the invention, as disclosed by a reading of the specification as a whole, are not limited to the use of the film coated spheroid compositions described in the specification. 181 In the result, I do not think the specification when read as a whole - including all that is incorporated by reference - provides a fair basis for claim 27 insofar as it is dependent on claims 1 to 17. It follows that claim 27 is also invalid on the ground that it does not comply with the requirements of s 40(3) of the Act. I certify that the preceding forty-nine (49) numbered paragraphs are a true copy of the Reasons for Judgment herein of the Honourable Justice Nicholas.

Associate: Dated: 28 October 2011 IN THE FEDERAL COURT OF AUSTRALIA NEW SOUTH WALES DISTRICT REGISTRY GENERAL DIVISION NSD 1533 of 2010

BETWEEN: SIGMA PHARMACEUTICALS (AUSTRALIA) PTY LTD ACN 004 118 594

IN THE FEDERAL COURT OF AUSTRALIA NEW SOUTH WALES DISTRICT REGISTRY GENERAL DIVISION NSD 1603 of 2010

IN THE FEDERAL COURT OF AUSTRALIA NEW SOUTH WALES DISTRICT REGISTRY GENERAL DIVISION NSD 1644 of 2010

JUDGES: BENNETT, NICHOLAS AND YATES JJ DATE: 28 OCTOBER 2011 PLACE: SYDNEY

YATES J 182 I have had the considerable advantage of reading in draft the reasons for judgment prepared by Bennett J. 183 I agree with Bennett J that claims 1 to 17 and 27 (when dependent on claims 1 to 17) of the Patent have the deferred priority date of 20 December 2006, with the consequence that the claims are not novel. In this connection, Wyeth has accepted that, if the deferred priority date is the correct priority date of those claims, they will have been anticipated by the sale of its own ER form of venlafaxine hydrochloride, EFEXOR XR, in Australia from 1999. 184 I wish to add, however, some observations of my own, reflecting more particularly my reasons for this outcome. For ease of reference, I will use the abbreviations adopted by Bennett J.

The Priority Document 185 In her reasons for judgment, Bennett J has described the disclosures in the Priority Document, which I gratefully adopt. 186 On reading the Priority Document it is clear, in my view, that Wyeth, as the patent applicant, is disclosing, to the person skilled in the art, the invention of a particular ER formulation of venlafaxine hydrochloride which has, as its essential features, spheroids comprised of venlafaxine hydrochloride, microcrystalline cellulose and HPMC, coated with ethyl cellulose and HPMC. These essential features are adopted as essential features of the encapsulated formulations and compositions claimed in claims 1 to 8 of the Priority Document. 187 The disclosed context for this claimed invention is that venlafaxine (in the form of its acid addition salts) is an important drug used for the treatment of depression. As such, it is administered to human adults as compressed tablets containing venlafaxine hydrochloride in doses ranging from 75 to 350 mg/day. These are divided doses, administered two or three times a day. The reason for this dosing regimen is that this formulation exhibits rapid dissolution, resulting in a rapid increase in blood plasma levels of the active ingredient, venlafaxine hydrochloride, shortly after administration, followed by a decrease in these blood plasma levels over time, leading to "sub-therapeutic" plasma levels of the active ingredient after about 12 hours. 188 It is clear that the reference in the Priority Document to "sub-therapeutic plasma levels" is to the therapeutic efficacy of venlafaxine hydrochloride administered in this formulation for the treatment of depression. It is not suggested that doses of venlafaxine hydrochloride from 75 to 350 mg/day would have therapeutic efficacy for any other indication. Indeed, no other indication is disclosed that would be suitable for treatment by venlafaxine, regardless of dosage or dose form. The consequence of this conventional dosage regimen is that, in the treatment of depression, about 45% of patients experience nausea, with vomiting (emesis) occurring in about 17% of patients. 189 The Priority Document makes clear that a benefit of this invention is that, when administered, it provides "a method for obtaining a flattened drug plasma concentration to time profile". In other words, the sharp peaks and troughs in blood plasma levels induced by multiple daily dosing with venlafaxine hydrochloride tablets, in accordance with the conventional regimen described, are eliminated. Thus, by using the "one-a-day venlafaxine hydrochloride formulations of this invention", the level of nausea and incidence of emesis are reduced, compared with "the plural daily dosing regimen" using venlafaxine hydrochloride tablets. 190 It is clear that the reference to the "one-a-day formulations of the invention" is to the extended release spheroid formulation in which the spheroids comprise venlafaxine hydrochloride, microcrystalline cellulose and HPMC, and in which the spheroids are coated with ethyl cellulose and HPMC. The use of the plural "formulations" simply denotes that various embodiments of the formulation will have these essential features. Some of these are exemplified in the Priority Document. 191 The Priority Document makes a number of additional, important disclosures. 192 First, the Priority Document discloses that it was "completely unexpected" that an extended release formulation containing venlafaxine hydrochloride could be obtained. This is because the hydrochloride of venlafaxine proved to be extremely water soluble. 193 Secondly, the Priority Document discloses that, despite numerous attempts, the production of ER tablets by hydrogel tablet technology proved to be "fruitless". This is because the compressed tablets were either physically unstable or dissolved too rapidly in dissolution studies. This led Wyeth to conclude, and thus to disclose in the Priority Document, that it was "impossible to achieve with hydrogel tablet technology" a formulation that had the desired dissolution rate of a sustained release dosage form of venlafaxine hydrochloride. However, the desired dissolution rate had been achieved "with the film-coated spheroid compositions of this invention". Once again, it is clear that this reference is to the formulation having the essential features to which I have referred. 194 The Priority Document refers to a "use aspect of this invention", being "a method for moderating the plural blood plasma peaks and valleys attending the pharmacokinetic utilization of multiple daily tablet dosing with venlafaxine hydrochloride". However, both the language of this statement, and the particular context in which it is made, leave no doubt, in my view, that this method is achieved "through administration of the venlafaxine formulation of this invention", not any formulation of venlafaxine hydrochloride that does not have, as its essential features, spheroids comprised of venlafaxine hydrochloride, microcrystalline cellulose and HPMC, coated with ethyl cellulose and HPMC. The method is thus formulation-dependent and referable only to the inventor's particular ER spheroid formulation of venlafaxine hydrochloride. 195 In short, what is relevantly disclosed is the described formulation and the use of the described formulation, not any formulation, to achieve certain outcomes (the diminution of nausea and emesis and the elimination of peaks and troughs of drug concentration in blood plasma). When the Priority Document records the blood plasma levels of venlafaxine over time in comparing IR tablets with ER capsules, it is clear that the results for ER capsules have been obtained from an analysis of ER capsules containing spheroids of venlafaxine hydrochloride having the essential features to which I have referred. There is nothing in the Priority Document to suggest that these results are not formulation-dependent. In particular, the Priority Document does not disclose that these results will be the same as, or predictive of, the results that would be obtained by using any ER formulation of venlafaxine hydrochloride, including any other encapsulated ER formulation, in the same studies. 196 My conclusions are based on a reading of the text of the Priority Document, giving it meaning according to the language and syntax adopted by its author. Although such a document must be read through the eyes of the person skilled in the art, the parties did not suggest that, in the respects to which I have referred, the person skilled in the art would read the Priority Document in a way that did not give its text its ordinary and plain English meaning. There was some debate on appeal about how the person skilled in the art would understand the expressions "subject" and "patient" where used with reference to Tables 2 and 3 of the Priority Document. In my view it is not necessary to resolve that debate because it does not affect in any material way the scope or content of the disclosures to which I have referred.

The Amended Patent 197 In her reasons for judgment, Bennett J has fully described the various deletions and additions, and other amendments, made to the Original Patent (which, in relevant respects, is accepted to be indistinguishable from the Priority Document, the Grandparent Application and the Parent Application) which are reflected in what is now the Amended Patent. 198 As Bennett J has demonstrated in her reasons for judgment, the 2006 Amendments made a substantial alteration to the description of the invention in the Original Patent. The invention is no longer described as being the specific ER spheroid formulation or the use of that formulation in providing a method for moderating "the plural blood plasma peaks and valleys" attending multiple daily dosing with venlafaxine hydrochloride, thereby reducing the level of nausea and incidence of emesis as side effects of that dosing regimen. Rather, the invention is described as a series of methods (namely, a method of providing a therapeutic blood plasma concentration of venlafaxine hydrochloride over a 24 hour period; a method of moderating the plural blood plasma peaks and valleys attending the pharmacokinetic utilization of multiple daily dosing with venlafaxine hydrochloride; a method of reducing the level of nausea and the incidence of emesis in a patient in need of venlafaxine; and a method of treating depression in a patient in need of such treatment), involving "a single daily dosing formulation of venlafaxine hydrochloride". 199 In the disclosure of these methods, the specific ER spheroid formulation of the Original Patent is given as a non-limiting example of an ER formulation that can be used. Having said this, the Amended Patent still incorporates, by reference, the entire disclosures of the Grandparent Application and the Parent Application (and hence the Original Patent) and, expressly, the disclosure that the production of an ER formulation of venlafaxine hydrochloride by hydrogel tablet technology had proved to be "fruitless" or "impossible to achieve", either because the compressed tablets are physically unstable or because they dissolve too rapidly in dissolution studies to provide the desired dissolution rate of a sustained release dosage form of that active ingredient. 200 The apparent shift in the Amended Patent from the Original Patent, is from (a) a specific ER spheroid formulation and its use in a method or methods, to (b) a variety of methods involving the use of "a single daily dosing formulation of venlafaxine hydrochloride" with certain peak blood plasma levels (including over time) and/or a specific dissolution profile, of which the specific ER spheroid formulation is but an example. 201 The claims of the Amended Patent make clear that it is not essential to the alleged invention that this single daily dosing formulation be an ER formulation (save for claim 15) or an encapsulated formulation (save for claim 27). 202 Claim 18 of the Amended Patent claims a formulation of venlafaxine hydrochloride containing a "therapeutically effective amount of spheroid core" comprising venlafaxine hydrochloride, microcrystalline cellulose and HPMC, the spheroid core being coated with a coating comprising ethyl cellulose and HPMC (that is, the specific ER spheroid formulation disclosed in the Priority Document, and described as an example formulation in the specification of the Amended Patent). Claims 19 to 26 are expressed to be dependent, directly or indirectly, on claim 18. 203 In the present case, claim 18 and its immediately dependent claims are not engaged in the case for invalidity raised by the appellants or in the case for threatened infringement raised by Wyeth. Those claims can, therefore, be put to one side.

The determination of the priority date 204 The determination of the priority date of the relevant claims depends upon: (a) the application of s 114 of the Act and reg 3.14(b) of the Regulations, or if those provisions are not applicable; (b) the successive application of reg 3.12(1)(c) in respect of the Parent Application and Grandparent Application, and thereafter the application of reg 3.12(1)(b) in respect of the Priority Document, or, if those regulations cannot be satisfied, the application of reg 3.12(1)(a) of the Regulations. 205 If, by reason of the 2006 Amendments, a relevant claim of the Amended Patent claims matter that was in substance disclosed as a result of amending the specification (s 114), the priority date of that claim will be the date of filing of the statement of amendments that resulted in that disclosure (reg 3.14(b)), namely 20 December 2006. 206 If, by reason of the application of a fair basing analysis involving a consideration of the Parent Application, Grandparent Application and the Priority Document (regs 3.12(1)(b) and (c)), it is not established that a relevant claim is fairly based on matter disclosed in each of those documents (which the parties accept are relevantly the same for practical purposes), the priority date for the claim will be the filing date of the application for the Original Patent (reg 3.12(1)(a)), namely 30 October 2003. 207 In either case, the priority date of the claim would be after Wyeth's sale in Australia of EFEXOR XR in 1999. 208 On appeal, the appellants' submissions concentrated on how regs 3.12(1)(b) and (c) did not apply to the relevant claims of the Amended Patent in light of the disclosures in the Priority Document. Regulation 3.12(1), however, is expressed to be subject to reg 3.14. In the present case the correct starting point to determine the priority date is the question whether s 114 applies to one or more of the claims of the Amended Patent. 209 Furthermore, the appellants tended to treat the proper application of reg 3.12(1) as resulting in the deferred priority date of 20 December 2006, whereas, if their analysis is otherwise correct, the priority date would be, as I have indicated, the date of filing the application for the Original Patent, namely 30 October 2003. 210 The same approach, with its apparent conflation of regs 3.12(1) and 3.14(b), was apparently pressed on the primary judge: see Reasons [9] and [153]-[154]. It may be that this was because the parties had agreed that the test under s 114 (i.e. whether a claim of a complete specification claims "matter that was in substance disclosed" as a result of amending the specification) was "the same" as the test for determining whether a claim is fairly based on a specification as required by s 40(3) of the Act: Reasons [154]; cf ICI Chemicals & Polymers Ltd v The Lubrizol Corporation Inc (2000) 106 FCR 214 at [118] and the cases there cited. 211 Certainly on appeal, Wyeth advocated this approach. It submitted that reference to s 114 added nothing: if the relevant claims of the Amended Patent were fairly based on the Priority Document they would not claim matter in substance disclosed as a result of any amendment. However, this submission is only possible because of the parties' acceptance that the specification of the Original Patent is relevantly the same as the specification of the Priority Document, for practical purposes. 212 In light of the way the parties conducted this aspect of the case before the primary judge, and on this appeal, the first question of present significance is: what matter is disclosed by the Priority Document? The answer to this question also answers the question of what is disclosed by the Original Patent. 213 The primary judge held that there were two inventions disclosed: an encapsulated formulation; and "a method for obtaining a certain drug to plasma relationship over time yielding a 'tighter plasma therapeutic range control' than multiple daily dosing, eliminating the sharp peaks and troughs in blood plasma levels induced by multiple daily dosing and thereby reducing the level of nausea and incidence of emesis that attend multiple daily dosing": Reasons [165]. 214 In arriving at this conclusion, the primary judge was persuaded by Wyeth's submission (repeated on appeal) that this conclusion is supported by the disclosures of claims 9 and 10 of the Priority Document. Those claims are as follows: 9. A method for providing a therapeutic blood plasma concentration of venlafaxine over a twenty four hour period with diminished incidences [sic] of nausea and emesis which comprises administering orally to a patient in need thereof, an encapsulated, extended release formulation that provides a peak blood plasma level of venlafaxine in from about four to about eight hours, said formulation containing venlafaxine hydrochloride as the active ingredient. 10. A method for eliminating the troughs and peaks of drug concentration in a patients [sic] blood plasma attending the therapeutic metabolism of plural daily doses of which comprises administering orally to a patient in need thereof, an encapsulated, extended release formulation that provides a peak blood plasma level of venlafaxine in from about four to about eight hours, said formulation containing venlafaxine hydrochloride as the active ingredient. 215 Wyeth submitted, and the primary judge accepted, that these claims disclose a method that is not limited to the use of any particular formulation and that the references in the Priority Document to the inventor's failed efforts to prepare a hydrogel tablet formulation do not eliminate the independent disclosure of a method of treatment. 216 I am, with respect, unable to agree with that conclusion. 217 Although claims 9 and 10 of the Priority Document refer only to "an encapsulated, extended release formulation" containing venlafaxine hydrochloride as the active ingredient, without expressly referring to the specific ER spheroid formulation in the body of that document, in my view the words "extended release formulation" in those claims can only be really understood, in their context, as implicitly disclosing "the extended release formulations of this invention" in the detailed description of the invention, which have then been encapsulated. This description makes clear that the formulation is of "beads or spheroids" formed from an admixture of venlafaxine hydrochloride, microcrystalline cellulose and HPMC coated with a mixture of ethyl cellulose and HPMC, which is then encapsulated. 218 This is the widest description of the formulation given as "[Wyeth's] solution to the problem of preparation of the extended release drug containing formulations of this invention", that solution having been "completely unexpected", and the problem having arisen from the fact that the hydrochloride of venlafaxine proved to be extremely water soluble, thereby rendering numerous attempts to produce ER tablets by hydrogel technology "fruitless" and "impossible to achieve". 219 I am not persuaded that the Priority Document discloses, relevantly, anything more than the particular ER formulation, or more limited embodiments of it, including encapsulated embodiments, which was Wyeth's solution to the disclosed problem, and the consequent use of that formulation, or more limited embodiments of it. It discloses no other encapsulated formulation as the method of providing a therapeutic blood plasma concentration of venlafaxine over a 24 hour period with diminished incidence of nausea and emesis (claim 9) and as the method of eliminating the troughs and peaks of drug concentration in a patient's blood plasma attending the therapeutic metabolism of plural daily doses of venlafaxine (claim 10). 220 Moreover, I am unable to read the Priority Document, and in particular claims 9 and 10, as disclosing methods that can be performed by use of a postulated ER formulation of venlafaxine hydrochloride that the patent applicant itself describes as "fruitless" and "impossible to achieve". By implication, the Priority Document discloses that the performance of the methods using such a postulated formulation would also be "fruitless" and "impossible to achieve". 221 For these reasons, I share Bennett J's view that the primary judge erred in concluding that the second invention, as described by her Honour, was disclosed by the Priority Document. 222 The further questions that then arise are, first, do the relevant claims of the Amended Patent claim matter that was in substance disclosed as a result of amending the specification and, secondly, if necessary to be decided, are the relevant claims of the Amended Patent fairly based on matter disclosed in the Priority Document? 223 In my respectful view, the answer to the first of those questions is "yes" and the answer to the second of those questions is "no". 224 Each of these questions directs attention to what is in fact claimed, relevantly, in the Amended Patent. The focus of attention is, therefore, claims 1 to 17, and claim 27 (when dependent on claims 1 to 17). 225 I have referred to the fact that the relevant claims are directed to methods involving "a single daily dosing formulation of venlafaxine hydrochloride". Save for claims 15 (an ER formulation) and 27 (an encapsulated formulation), the formulation is not specified beyond the result to be achieved in terms of identified peak blood plasma levels and/or a specific dissolution profile. 226 Thus, aside from claims 15 and 27, what is now claimed in the Amended Patent, but not in substance disclosed in the Priority Document or the Original Patent, is that any single daily dosing formulation of venlafaxine hydrochloride that attains the specified results can be used in the claimed methods. This is how Wyeth asserts its monopoly rights. However, this development or advance was disclosed only by the 2006 Amendments. 227 It follows, in my view, that the priority date of claims 1 to 14, and claims 16 and 17 (when not dependent on claim 15), falls to be determined under s 114 of the Act and reg 3.14(b) of the Regulations. The same result ensues in relation to claim 15 (and claims 16 and 17 when dependent on claim 15) and claim 27 because, although these claims add the respective limitations of an ER formulation of venlafaxine hydrochloride which is encapsulated, neither claim is limited to the specific ER spheroid formulation of the Original Patent. 228 Thus, for this reason alone, claims 1 to 17 and 27 (when dependent on claims 1 to 17) have the deferred priority date of 20 December 2006. 229 Although it is unnecessary to determine the relevant priority date by reference to reg 3.12(1) of the Regulations, a similar result ensues because there is no real and reasonably clear disclosure in the Priority Document of any method that is not dependent on the use of the specific ER spheroid formulation. 230 As I have discussed, the Priority Document makes clear that what is provided is a specific formulation, and its more limited embodiments, that can then be used in a method to achieve particular outcomes. What is discussed, and thus what is provided, is a particular formulation solution to a particular formulation problem. The more general method claims of the Amended Patent, limited so far as formulation is concerned only to "a single daily dosing formulation of venlafaxine hydrochloride", even as an ER formulation that is encapsulated, travel well beyond, and are not fairly based on, matter disclosed in the Priority Document. 231 Thus, if recourse to reg 3.12(1) were necessary, claims 1 to 17 and 27 (when dependent on claims 1 to 17) would have a priority date of 30 October 2003. 232 For these reasons, I am of the view that the primary judge erred in concluding that the relevant claims of the Amended Patent have a priority date of 25 March 1996.

Other challenges to validity 233 If claims 1 to 17 and 27 of the Amended Patent take the deferred priority date, or even the priority date of 30 October 2003, those claims will be invalid, for lack of novelty. It follows that the appeals should be allowed for that reason alone. 234 In those circumstances it is unnecessary to deal with the other grounds of invalidity advanced by the appellants. I propose, however, to briefly set out my conclusions on the fate of the appellants' challenges with respect to those grounds. In stating these conclusions it is convenient, for simplicity of exposition, to treat all relevant challenges on appeal as having been made by all appellants.

Internal fair basis 235 The primary judge rejected the appellants' contention that the relevant claims of the Amended Patent are not fairly based on the matter described in the specification: s 40(3) of the Act. 236 In my respectful view, the primary judge erred in her conclusion. My reasons for this view are influenced significantly by the features of the Amended Patent I discussed when dealing with the question of the correct priority date of the claims. 237 When the relevant claims refer to a single daily dosing formulation of venlafaxine hydrochloride, they include all such formulations having the result or results specified in the claims, and otherwise conforming to the limitations of the claims, including even an ER formulation produced as compressed tablets by hydrogel tablet technology, if such a formulation can be produced. I do not read the claims as implicitly limited to exclude such a formulation. Indeed, Wyeth did not contend for such a construction. To the contrary, it contended that it can claim, validly, all single daily dosing formulations of venlafaxine hydrochloride that achieve the results, and otherwise conform to the express limitations, of the claims. 238 Wyeth advanced two principal reasons to support this contention. 239 First, as a matter of textual comparison, Wyeth submitted that the relevant claims are supported by corresponding consistory clauses in the body of the specification. In this connection Wyeth submitted that there is nothing in the body of the specification that suggests that the description of the invention is narrower than the description in the consistory clauses. 240 Secondly, Wyeth submitted that, as a matter of principle, once it is recognised that the specification discloses a method, and enables one way of performing that method, it is entitled to claim all alternative means by which the method may be performed. In this connection, Wyeth sought to draw support from the statement of general principle in Shave v H.V. McKay Massey Harris Proprietary Limited (1935) 52 CLR 701 at 709, quoted with approval in Lockwood Security Products Pty Limited v Doric Products Pty Limited (2004) 217 CLR 274 at [59], to the effect that when, by a new application of principle, an inventor obtains a new result or thing, the inventor may claim all the alternative means by which the thing or result may be achieved. 241 In my view those submissions should not be accepted. 242 First, despite its deletions, additions and other amendments, the specification of the Amended Patent still incorporates, in the way that I have described above, the unambiguous statements that, so far as Wyeth is concerned, the search for an ER formulation produced by hydrogel tablet technology is "fruitless" and "impossible to achieve". Once again, these statements cannot be ignored, although Wyeth sought to do so by appealing to evidence from Professor Charman and Dr Marshall to the effect that the relevant passages in the specification dealing with the attempts to use hydrogel tablet technology do not represent statements of absolute fact, beyond the inventor's own endeavours. This evidence really diverts attention from the fact that the comparison for s 40(3) purposes is between the relevant claim and "the matter described in the specification". An argument based on an appeal to an abstract, independent or objective truth, according to the understanding of an expert witness, rather than to the matter described in the specification, really misses the point. 243 A consideration of the entirety of the specification of the Amended Patent, with its express incorporation of the entire disclosures of the Grandparent Application and the Parent Application, and the retention of the text concerning the "fruitless" endeavours to produce an ER formulation by hydrogel tablet technology, which was "impossible to achieve", shows that the consistory clauses do not reflect the description of the invention in the light of the specification as a whole: Lockwood at [87]; Atlantis Corporation Pty Ltd v Schindler (1997) 39 IPR 29 at 50. 244 Secondly, the statement of general principle in Shave does not mandate or permit a departure from a consideration of what is in fact disclosed, described and claimed in the patent specification for the purposes of applying s 40(3) of the Act. 245 As recourse to the judgment in Shave makes clear, the proper construction of the patent specification is all-important. At 709 Rich, Dixon, Evatt and McTiernan JJ observed: In the present case the plaintiff's specification contains no indication that he sought protection for the application of principle upon which the construction of his implement is based. Indeed it does not even appear from the specification that he appreciated the generality of the mechanical principles it brought together and the existence of variant means of applying them. He sought and secured simplicity of design and to this achievement his spindle contributed much. Whatever gains may be had by departing from his spindle, greater simplicity is not one of them. In our opinion his claim is for the mechanism he describes. 246 In that case, their Honours concluded that, although a principle was described in the specification, the inventor was not seeking to claim as his invention all alternative means by which a thing or result may be achieved. This conclusion resulted from the proper construction of the claims. The present case is somewhat different in that the immediate concern is: what is the matter described in the specification? Nevertheless, the approach referred to by their Honours is apposite. 247 In the present case it may be accepted that a new application of principle (although not necessarily an application of new principle) was involved in the invention as claimed. However, a method including an ER formulation of venlafaxine hydrochloride produced by hydrogel tablet technology is not part of the matter described in the body of the specification. Rather, it is matter that was effectively disclaimed in that part of the specification as being part of the invention. While the matter described in the body of the specification presages the possibility of workable formulations for use in the claimed methods other than the specific ER spheroid formulation exemplified, an ER formulation produced by hydrogel tablet technology is not one of them. Any principle described in the body of the specification is not an unqualified one so far as concerns the formulations that could be used in the methods of the claims. 248 Accordingly, the specification does not provide, by description, a basis for claiming any one of the methods performed by use of a single daily dosing formulation of venlafaxine hydrochloride produced by using hydrogel tablet technology. 249 I agree with Bennett J that, by seeking to claim methods which include such a formulation, Wyeth has travelled beyond the matter described in the specification. For that reason alone, claims 1 to 17 are not fairly based for the purposes of s 40(3) of the Act. The same result ensues for claim 27 (when dependent on claims 1 to 17). An encapsulated formulation is one that can comprise tablets contained within the capsule. Alphapharm's ENLAFAX - XR product is of that kind: see Reasons [628]. Claim 27 would include a method involving the use of an encapsulated formulation where the capsule contents are produced by hydrogel tablet technology. 250 For completeness, I also agree with Bennett J, substantially for the reasons given by her Honour, that, additionally, the relevant claims are not fairly based on the matter described in the specification of the Amended Patent to the extent that they are not limited to methods involving the treatment of depression: cf. claims 4, 8 and 14 where, for example, that limitation is provided.

Sufficiency 251 The primary judge rejected the appellants' contention that the specification does not describe the invention fully, including the best method known to Wyeth of performing the invention: s 40(2)(a). 252 In my view, the primary judge did not err in her conclusion. 253 The main plank of the appellants' challenge was that, given the apparent width of the relevant claims to include methods using a single daily dosing formulation of venlafaxine hydrochloride produced by hydrogel tablet technology, there is no description in the specification that would enable the performance of the claimed methods using such a formulation. 254 That proposition may be accepted. However, in my view, that acceptance does not lead to the conclusion that the Amended Patent is invalid for want of compliance with s 40(2)(a) of the Act. 255 The specification of the Amended Patent fully describes the invention that can be validly claimed. In so doing, the specification lays bare the fruitlessness and impossibility of Wyeth's endeavours in seeking to achieve an ER formulation using hydrogel tablet technology. The specification, by the provision of examples, enables the claimed methods to be performed. Wyeth was not required by s 40(2)(a) of the Act to describe every formulation that might be used in the performance of those methods; nor was it required to describe a formulation that was found to be "fruitless" or "impossible to achieve". 256 In my view the problem with the specification, for s 40 purposes, is not one of insufficiency of description, but one of impermissible claim width.

Clarity 257 The primary judge rejected the appellants' contention that the relevant claims of the Amended Patent do not define the claimed invention clearly: see s 40(3). The appellants' contention was directed to the phrase "therapeutic blood plasma concentration" where used in those claims. 258 Based on the argument developed on appeal, there seems to be no error suggested in the primary judge's acceptance that the phrase should be given its ordinary English meaning as referring to a single daily dosing of a formulation of venlafaxine hydrochloride that achieves a blood plasma concentration of venlafaxine that is therapeutically effective. The import of the appellants' submissions is that, so understood, the phrase is unclear: it does not provide a workable standard because there is no way of predicting in advance what the therapeutic concentration for a particular formulation will be, thereby enabling the person skilled in the art to avoid the possibility of infringement. In advancing these submissions the appellants did not suggest that the determination of the therapeutic efficacy of a given formulation of venlafaxine hydrochloride itself presents a challenge to the person skilled in the art. 259 In my view the appellants' contention raises, in a conventional way, a criticism that can be made of many claims limited by result. As a general rule, however, such claims do not fail for lack of clarity simply because further steps must be taken by the person skilled in the art, in the nature of trial and error or routine testing not involving invention, in order to understand when the result will be achieved: No-Fume Ltd v Frank Pitchford & Co Ltd (1935) 52 RPC 231 at 238, 245-246 and 247-249. The necessity for, or extent of, the work required in that regard may point to the possibility of insufficient description, but no challenge to validity of that kind has been raised in this respect. 260 Like Bennett J, I am not persuaded that the appellants have shown that the primary judge erred in her conclusion.

False suggestion 261 The primary judge rejected the appellants' contention that the statements in the Amended Patent that it was completely unexpected that an ER formulation could be achieved because of the fruitless attempts to obtain such a formulation by hydrogel tablet technology, and that it was impossible to achieve with hydrogel tablet technology a dosage form that achieved the desired dissolution rate, constituted a false suggestion or misrepresentation on which the Patent was obtained: see s 138(3)(e). 262 I agree with Bennett J, substantially for the reasons advanced by her Honour, that the appellants have not demonstrated a false suggestion that was material to the grant of the Patent.

Lack of inventive step 263 The primary judge rejected the appellants' contention that the invention as claimed is not a patentable invention because it lacks an inventive step: see ss 18(1)(b)(ii) and 138(3)(b). 264 In coming to that conclusion the primary judge gave detailed consideration to a significant body of factual and scientific evidence, including opinion evidence, which had been adduced by the parties on that question. In undertaking that task the primary judge identified a significant number of complex factual issues that were necessary to be decided in the present case in order for her to reach a finding on the ultimate question of inventive step: see Reasons [264]. 265 The primary judge's reasons stand as ample testimony of the magnitude of that task and of the methodical way in which her Honour considered those issues: see Reasons [265]-[514]. A significant part of the argument on appeal was devoted to challenging the primary judge's factual findings and conclusions that were made along the way to reaching her conclusion on that ultimate question, in an endeavour to identify appealable error. 266 The framework for considering whether an inventive step is involved in an invention is provided by s 18(1)(b)(ii) of the Act, assisted by ss 7(2) and (3) and the definitions of "prior art base" and "prior art information". A question of comparison is involved. Section 18(1)(b)(ii) makes clear that the invention is the invention "so far as claimed in any claim". It also makes clear that the invention, as claimed, must be compared with the "prior art base as it existed before the priority date of that claim". 267 The primary judge's consideration of the question of inventive step was undertaken by making a comparison of the invention, as claimed in each of the relevant claims, with the prior art base as it existed at 25 March 1996, based on her conclusion that Wyeth was entitled to rely on the date of filing of the Priority Document as the priority date for those claims. This included a consideration of what information comprised the prior art base at that time, including what knowledge was part of common general knowledge. This consideration also took place in a context where the primary judge had rejected the appellants' contention that the relevant claims were not fairly based for the purposes of s 40(3) of the Act. 268 It is clear that the determination of the correct priority date is pivotal to the comparison required by s 18(1)(b)(ii) of the Act. If the correct priority date is not 25 March 1996, but the deferred priority date of 20 December 2006 (as, in my opinion, it is) or even 30 October 2003, it can be appreciated that the prior art base may be radically different from that considered by her Honour, especially where, as here, Wyeth's own embodiment of the invention had been on the market for a number of years before the relevant priority date and would have been prior art information. 269 In my view there is no utility in the Full Court now proceeding to deal with this part of the case by reference to the incorrect priority date of 25 March 1996. To do so would not only be to ignore critical findings made in this appeal about the relevant priority date but also to engage in an essentially barren exercise given that, regardless of the priority date chosen, the relevant claims are not valid, for want of fair basis under s 40(3) of the Act.

Entitlement and false suggestion 270 The primary judge rejected the appellants' contention that Wyeth's failure to correctly nominate all inventors in its application for the Patent constituted a false suggestion or misrepresentation on which the Patent was obtained: see s 138(3)(e). 271 The primary judge also rejected the appellants' contention that Wyeth was not entitled to the Patent: see s 138(3)(a). 272 It is convenient to deal with these two challenges to validity together. 273 As to the question of false suggestion or misrepresentation, there is no debate about the fact that Ms Sherman was shown, incorrectly, to be the only inventor on Wyeth's application for the Patent. The primary judge found that Messrs Clark, Lamer and White were co-inventors with Ms Sherman. Her Honour also found that all these inventors were employees of Wyeth at all material times. In its patent application, Wyeth claimed to be the person entitled to the invention based on the assignment to it of the rights in and to the invention. The primary judge reasoned that the representation that Ms Sherman was the sole inventor could not have been material to the grant of the Patent because the only material representation was Wyeth's entitlement as assignee of the invention, a question which the primary judge subsequently resolved in Wyeth's favour: see Reasons [552] and [554]. 274 In my view, no error has been demonstrated in the primary judge's approach to determining this aspect of the appellants' case on false suggestion and misrepresentation. I agree with the primary judge that the determination of this issue depends on whether the appellants could demonstrate that Wyeth was not entitled to the Patent in reliance on s 15(1) of the Act. 275 As to the question of entitlement, the evidence before the primary judge revealed that the inventors had each entered into a standard form invention and disclosure agreement with a subsidiary company, Ayerst Laboratories Inc (Ayerst), of American Home Products Corporation (American Home Products). Between 1996 and 2001 the inventors also executed a series of specific assignments of patent and other rights in the invention to American Home Products. 276 On 11 March 2002, American Home Products merged with one of its subsidiary companies, to become Wyeth. 277 Moreover, through a series of corporate reorganisations, Ayerst was merged with another company, the surviving corporation being a company ultimately named, as at 21 March 2002, Wyeth Pharmaceuticals Inc (Wyeth Pharmaceuticals). In December 2002, Wyeth Pharmaceuticals was merged into another Wyeth subsidiary company, with all the "estate, rights, privileges, immunities, powers and franchises of Wyeth Pharmaceuticals being vested in and held and enjoyed by" the Wyeth subsidiary company, the name of which was then changed to Wyeth Pharmaceuticals Inc. I include that company in the description "Wyeth Pharmaceuticals". 278 Annual Reports lodged under United States securities legislation for the years 2001 to 2008 showed Wyeth Pharmaceuticals to be a wholly-owned subsidiary of Wyeth. 279 Part of the appellants' case before the primary judge was that Wyeth had an evidentiary onus to establish its entitlement. The primary judge rejected that contention, correctly in my view. It was for the appellants to establish a lack of entitlement, not for Wyeth to prove its entitlement. That is not to say, however, that the appellants could not discharge that onus by reference to material that Wyeth itself had tendered on this issue. 280 In this connection the appellants did not seek to adduce their own evidence. Their initial challenge to Wyeth's entitlement was based solely on the alleged false suggestion or misrepresentation arising from the fact that only Ms Sherman was shown on Wyeth's original application for the Patent, not on the history or the effect of corporate reorganisations revealed by Wyeth's evidence. However, in light of the evidence adduced by Wyeth, the appellants' approach was to raise arguments directed to the sufficiency of that evidence or to what that evidence might otherwise show. 281 The highest that the appellants' case rose on this issue at trial was that "the person most likely to be entitled to the invention claimed in the Patent is a company the corporate status of which is unclear, or in any event has not come forward in these proceedings": see Reasons [572]. Why this should be so is not clear because the evidence before the primary judge either showed or supported the conclusion that American Home Products had been merged into the one surviving corporation that was Wyeth, and Ayerst, through a succession of mergers, had been merged in the surviving corporation that was Wyeth Pharmaceuticals. Furthermore, Wyeth Pharmaceuticals was a wholly-owned subsidiary of Wyeth. 282 The primary judge concluded that the appellants had not discharged their onus of establishing lack of entitlement in the face of the evidence of assignment of all rights in connection with the invention to Wyeth: see Reasons [588]. The evidence of assignment was constituted by the specific assignments by the inventors to Wyeth. 283 The primary judge went further and held that, in any event, the terms of the standard form invention and disclosure agreements were themselves sufficient to establish Wyeth's entitlements to the invention. The primary judge held that clauses 4, 5 and 8 of those agreements provided "a workable scheme for the identification and vesting of all rights as identified in Wyeth's subsidiary … in circumstances where Wyeth was the sole shareholder": see Reasons [589]. 284 Those clauses were as follows: 4.(a) AYERST and EMPLOYEE agree that all Confidential Information, including its uses and the ideas related to its advertisement and promotion, is AYERST's sole property. Further, all the Confidential Information developed, improved, discovered, invented or conceived by EMPLOYEE, solely or in concert with others, during the term of his (or her) employment with AYERST, shall become AYERST's sole property. 5. EMPLOYEE will immediately disclose and assign to AYERST his (or her) entire right and interest in and to (1) developments, improvements, discoveries and inventions related to Confidential Information; (2) any applications for patents that may be filed relating to Confidential Information, and (3) any letters patent that may issue relating to such Confidential Information. He (or she) will also promptly give all assistance possible, including signing of necessary documents, for the preparation and prosecution of any application for new, revised or reissued patents on the above, or divisional or corresponding foreign patent applications thereon, as may be requested by AYERST. 8. EMPLOYEE agrees that every part of this agreement applies to, inures to the benefit of, and is enforceable by any of the subsidiary, affiliate, associate, or successor companies of AYERST or its parent company, American Home Products Corporation. In addition, this Agreement shall insure [sic] to the benefit of and be binding upon EMPLOYEE, EMPLOYEE'S heirs, executors, and administrators. 285 Her Honour then concluded, in accordance with a submission advanced by Wyeth, that, by accepting the specific assignments made to it, and in applying for the Patent in its own name, Wyeth had signified its assent to that transaction on its own behalf and on behalf of its wholly-owned subsidiary Wyeth Pharmaceuticals. That assent was consistent with clause 8 of the standard form invention and disclosure agreement. 286 The substance of the appellants' contentions on appeal, reflected in submissions made by Alphapharm, was that the primary judge had concluded (correctly, according to the appellants' submissions) that the invention had been assigned to Ayerst by the standard form invention and disclosure agreements, but that her Honour erred by finding that: (a) those rights vested in the company called Wyeth Pharmaceuticals, following the merger in December 2002; and (b) Wyeth had established that there had been an assignment, disposition or alienation of those rights to it, based on the fact that it was the sole shareholder of Wyeth Pharmaceuticals. The appellants maintained the position that it was not sufficient for Wyeth to rely on the documents it had tendered; it had to go further and prove the legal effect of the documents it had tendered including, where relevant, the content of foreign law. 287 In my view the primary judge did not err in rejecting the appellants' contention that Wyeth was not entitled to the Patent. It was not incumbent on Wyeth to positively prove its chain of title. It was entitled to apply for the Patent on an assertion as to its entitlement. That assertion of its entitlement was based on its status as "the assignee of the actual inventor": see the Request for a Standard Patent and Notice of Entitlement lodged by Wyeth on 30 October 2003 and Reasons [541]. That claimed entitlement derives from s 15(1)(c) of the Act which, for its own purposes, treats an "invention" as a species of property. The position revealed on the face of the documents was consistent with Wyeth's assertion as to its entitlement. 288 First, there were specific assignments to Wyeth of the rights in and to the invention by the inventors. Wyeth is entitled to rely on those documents for what they show on their face. 289 Secondly, in my view, clauses 4(a) and 5 of the standard form invention and disclosure agreement did not operate to immediately assign all rights in and to the invention to Ayerst. Rather, those clauses constituted a contractual obligation on the part of the inventor to give over inventions to Ayerst and to provide other assistance to Ayerst in applying for patents in respect of inventions. It follows that the standard form invention and disclosure agreements did not stand in the way of the specific assignments taking effect in favour of Wyeth, according to their terms. There is no evidence to suggest that Wyeth Pharmaceuticals or any other surviving Wyeth subsidiary company has asserted a superior right to Wyeth's or could realistically do so over Wyeth's objection. 290 In this connection, I am not satisfied that the primary judge did find (as the appellants contend) that the invention was assigned by the standard form invention and disclosure agreements. The primary judge found no more than that the standard form invention and disclosure agreements provided a "workable scheme" for the identification and vesting of rights, which her Honour then considered in the context of Wyeth itself taking direct assignments from the inventors in circumstances where, absent any evidence to the contrary, Wyeth Pharmaceuticals, as the successor of Ayerst and as Wyeth's wholly-owned subsidiary, was subject to Wyeth's corporate will and could be taken to have assented to such transfers to its parent company. 291 If the appellants wished to contend, contrary to what was shown on the face of the documents in evidence, that Wyeth Pharmaceuticals was not the successor of Ayerst or that Wyeth Pharmaceuticals was not a wholly-owned subsidiary of Wyeth (and, therefore, not subject to Wyeth's corporate will), or that, say, Wyeth Pharmaceuticals had asserted and maintained a valid prior claim to ownership of the invention, or that, realistically, it could and would make such a claim, then it was for them to adduce evidence of the relevant facts, including proof of relevant foreign law if necessary: see s 7(3)(a) of the Foreign Corporations (Application of Laws) Act 1989 (Cth). That position was not achieved by the appellants contending that Wyeth had failed to discharge an onus which it did not bear or by pointing, argumentatively, to the possibility of other legal outcomes.

Infringement 292 The primary judge rejected Alphapharm's contention that the use of its ENLAFAX XR formulation in the methods of the relevant claims would not infringe those claims because ENLAFAX XR "is hydrogel tablet technology within the meaning of the specification, and therefore does not infringe the claims". 293 Acceptance of Alphapharm's contention required acceptance of the related contention that the words "a single daily dosing formulation of venlafaxine hydrochloride" should be construed as meaning "a single daily dosing formulation of venlafaxine hydrochloride (not utilising hydrogel tablet technology)". 294 For the reasons given above in relation to the issue of internal fair basing, the relevant claims do not bear the construction for which Alphapharm contends. 295 It follows, in my view, that the primary judge did not err in her conclusion. However, as I have also found, the impermissible breadth of the relevant claims stands as an independent reason why those claims are invalid.

disposition 296 The appeals should be allowed. I agree with the orders proposed by Bennett J. I certify that the preceding one hundred and fifteen (115) numbered paragraphs are a true copy of the Reasons for Judgment herein of the Honourable Justice Yates.