Pfizer Inc v Commissioner of Patents

The applicant's submissions 26 The main platform of the applicant's case is that the Deputy Commissioner erred in taking any account of the selection patent in determining whether voriconazole was in substance disclosed in the parent patent. The applicant submits that the Deputy Commissioner should have confined himself to the parent patent, assisted only by the evidence of a person skilled in the art as to the construction of that patent. 27 Similarly, it is submitted that the Deputy Commissioner was not entitled to take into account comments made during prosecution of the selection patent. The applicant also relies upon Prestige Group (Australia) Pty Ltd v Dart Industries Inc (1990) 26 FCR 197 at 213 to support the proposition that file wrapper estoppel is not to be taken into account in the construction of the claims or specification of a patent. In this case, the Deputy Commissioner took account of "admissions" made during prosecution of the selection patent in the construction of the specification of the parent patent. 28 Pfizer does not accept that the test of "real and reasonably clear disclosure" necessarily applies to s 70(2)(a) of the Act. 29 Mr Webb SC who appears with Ms Howard for Pfizer, submits that the words "in substance disclosed" in s 70(2)(a) ought to be given a different meaning to the words "fairly based on matter described", being the words in s 40(3) of the Act and that these words import a different test. Mr Webb submits that the Deputy Commissioner erred in assuming that there is no difference between the requirement of "in substance disclosure" in s 70(2)(a) and the requirement in s 40(3) that a claim be fairly based on matter described in the specification. Counsel relies on the use of different language in different parts of the Act including the words "describe" and "disclose", to provide different tests. It is submitted that this question of construction of s 70(2)(a) has not been decided in previous decisions of the Court. 30 Mr Webb submits that the test in the Act is in terms of "in substance disclosure" and that emphasis on words such as "real" or "bare disclosure" is not only unwarranted, it is also an attempt to substitute for the words of the section (RGC). 31 Mr Webb also submits that the words "in substance" import a lesser requirement of disclosure than the test for fair basis. 32 It is further submitted that, where the same words "in substance disclosed" appear in two different sections of the Act, a different test is imposed, as the phrase has different work to do. This was put by Mr Webb as 'what may be an in substance disclosure for the purpose of one test might not be an in substance disclosure for the other'. Pfizer sought to draw a distinction between the meaning of "in substance disclosed" in s 102(1) of the Act for the purposes of amendment and "must in substance be disclosed" in s 70(2)(a) of the Act for the purposes of extension of term. 33 Pfizer relies on the evidence of Dr Stamford that voriconazole can be clearly identified in the parent patent and, therefore, that there is "in substance disclosure".

The respondent's submissions 34 Mr Catterns stated that the Deputy Commissioner did not base his decision on the existence of or the validity of the selection patent. It is submitted that he 'correctly treated the selection patent as evidence, in particular as an admission, which was relevant to the statutory question'. 35 Mr Catterns submits that, as Pfizer relied upon evidence to establish that voriconazole was in substance disclosed in the parent patent, the Deputy Commissioner rightly took into account the selection patent as evidence of admissions by Pfizer. 36 It is worth noting the way in which Mr Catterns supports the use of the selection patent in the decision of the Deputy Commissioner: 'The existence of a selection patent is evidence of the fact that the special properties of the particular compound were not recognized at the date of the filing of the original specification. In other words, while the broad class of compounds was disclosed, there was no "real and reasonably clear" disclosure of the specific compound, either at the time of filing or now.' 37 Mr Catterns also submits that the applicant's evidence did not address the question of the nature of the work required to select the compound from the many other compounds encompassed by the general formula, said to be central to whether it was in substance disclosed in the parent patent. 38 He disputes the proposition that the mere inclusion of voriconazole within a formula amounts to an "in substance disclosure", within s 70(2)(a) of the Act. He submits that a broad formula, which includes voriconazole within its scope cannot constitute, without more, an "in substance disclosure" or a "real and reasonably clear disclosure" of that compound. 39 Mr Catterns submits that the test of real and reasonably clear disclosure applies and that this must be more than a bare disclosure in order to give the word 'real' some content. He submits that the "in substance disclosure" must be informative. 40 Mr Catterns submits that the words "in substance" do not import a lesser test of meaning "it's nearly there" but rather looks to the question as a matter of substance or quality.

Is the selection patent relevant to the question of the construction of the parent patent? 41 Section 70(2)(a) is in Chapter 6, Part 3 of the Act entitled 'Extension of term of standard patents relating to pharmaceutical substances'. There is nothing in the section that requires examination of the validity of the patent sought to be extended. It is a question of whether s 70(2)(a) is satisfied. 42 It is accepted that voriconazole falls within the scope of the claims, so the question is whether voriconazole is in substance disclosed in the specification. This requires examination of the specification itself. 43 On 18 November 2004, the High Court delivered its judgment in Lockwood Security Products Pty Ltd v Doric Products Pty Ltd (2004) 2121 ALR 1 ('Doric'), after the hearing of this matter had concluded. The High Court made it clear that, in considering fair basis, an examination of the specification goes to the form that the specification takes (at [44]). There is no reason to introduce "inventiveness" or "meritoriousness" or inventive step (Doric at [46] and [48] and [53]-[54]). It is a question only of what is said in the specification (Doric at [72]). To the extent that there is any conflict between Doric and the observations of Gibbs J in Roche which were not part of the ratio of that case, clearly Doric is authoritative. 44 The same principles apply to a consideration of "in substance disclosure" in a specification. 45 In effect, the Deputy Commissioner took into account the selection patent in the construction of the parent patent. He considered the alleged new inventive step that resulted in the selection patent to be relevant to the construction of and the disclosures of the parent patent. 46 In my opinion the selection patent, either by reason of its existence or as evidence in the construction of the parent patent for the purpose of ascertaining disclosure within the meaning of s 70(2)(a), was irrelevant. 47 Counsel for both the applicant and the respondent compared the test in s 70(2)(a) with that of fair basis on matter disclosed in priority documents and of fair basis on matter described in the specification. They also discussed concepts of inventiveness and inventive step. It was in that context that the selection patent was taken as evidence of an inventive step. In particular, Mr Catterns submits that, if it takes an inventive step to derive the compound from the bare formula, there can be no real and reasonably clear disclosure of the compound. In support of that proposition, Mr Catterns relies upon Roche at 542-543 and Coopers Animal Health Australia Ltd v Western Stock Distributors Pty Ltd (1987) 15 FCR 382 ('Coopers') at 398. 48 As noted by the Deputy Commissioner, Roche is authority for the proposition that a claim to a single compound included in the class of chemical compounds covered by a chemical formula is fairly based (see Roche at 541). The question is whether the 'caveats' identified by Gibbs J in that decision are applicable to deprive the single compound of fair basis on the grounds that it was the subject of a claim to a later selection. 49 It is important to note that in Roche Gibbs J was considering the fair basis of the claims of a later selection patent on an earlier filed basic application for the purpose of establishing the earlier priority date of those later claims (at 531-532). The question was not the fair basis of a claim on the body of the same specification. 50 It was in that context that his Honour observed at 542-3: 'It is crucial, in my view, that it is not suggested that the compounds the subject of proposed claims 2, 3 and 4 have been selected because they have any special utility. If a basic application disclosed a large class of compounds, all of which were claimed to be of pharmaceutical utility, and it were found that the claim was false, in that only some of the compounds were useful, or it appeared that some of the compounds had a particular and peculiar value, there would be much to be said for the view that a claim limited to those compounds selected for their utility or special value would not be fairly based on matter disclosed in the basic application, at least if the basic application did not itself provide a guide to that selection, and a fresh inventive step were necessary to enable it to be made. Here, however a large class of compounds is disclosed, and clearly disclosed, in the basic application, and proposed claims 2, 3 and 4 in the complete specification are for compounds forming part of that class, but not selected because they alone are useful or because they have utility greater than that of other members of the class.' (emphasis added) 51 The reasoning in Roche would apply to a claim for fair basis of claim 12 of the selection patent (the claim for voriconazole) on the parent patent. It was in that context that Gibbs J (at 540-541) considered as relevant any suggestion that the claim to the utility of the compounds in the first basic application was false or that there was a fresh inventive step involved in the selection out of the class of those compounds for utility or special utility. 52 Roche does not, in my view, stand for the proposition that a subsequent patent can be relevant to the construction of an earlier, different patent. Nor does it stand for the proposition that the fact of a subsequent selection of a sub-class is relevant to the determination of the nature or extent of disclosure of the members of a class of compounds in the original patent. 53 The same analysis applies to the respondent's reliance on the admonition in Coopers at 398, that there must not be a fresh inventive step if there is to be fair basis. That case also concerned fair basis of claims in a later filed petty patent on an earlier filed provisional specification for the purpose of establishing the priority date of the claims of the petty patent. The compound in question in Coopers was not specifically mentioned in the provisional specification but was mentioned as part of the later claimed invention. Following Roche, a fresh inventive step was held to preclude fair basis for the claim in the later filed petty patent on the earlier specification. 54 The caveats in Roche and Coopers are not applicable to the construction of the parent patent in the present case. 55 In the present case, the selection patent was granted. That patent included a claim to the compound voriconazole. The inventive step was to establish a class of compounds within the generic formula, of which voriconazole was one, that had increased anti-fungal activity. If voriconazole was in substance disclosed in the parent patent, that may affect the validity of some of the claims of the selection patent. There may have been reasons why the patentee chose to file a second patent instead of seeking to amend the parent patent to include a specific claim to voriconazole. However, those issues play no part in the determination of whether s 70(2)(a) is satisfied, in the same way that issues of invalidity for lack of novelty or obviousness play no part in the determination of fair basis of the claims on the matter described in the specification (Doric at [48]).

Are the statements made by the patentee during prosecution of the selection patent relevant to the construction of the parent patent? 56 By parity of reasoning, the statements of the patentee during prosecution of the selection patent are not admissible in the construction of the parent patent for the purposes of determining what was "in substance disclosed" in that patent.

The test of in substance disclosed 57 A requirement for an extension of term is that the pharmaceutical substance per se must be both "in substance disclosed" in the complete specification and must in substance fall within the scope of the claims (s 70(2)(a) of the Act). It is said in the Explanatory Memorandum for the Patents Amendment Bill 1988 that introduced s 70(2)(a) of the Act that the criteria are to correspond closely to those employed in relation to 'allowability' of new or amended claims. 58 Lord Denning MR said in Ethyl Corporation's Patent [1972] RPC 169 at 195, as approved in RGC at 460 that 'the requirement of "fairly based" is virtually the same as the requirement that the amendment must be "in substance disclosed"'. Burchett J in RGC considered the meaning of 'allowability' of amendment by application of s 102(1) of the Act and found that the question is simply whether, in the words of that section, 'as a result of the amendment, the specification would claim matter not in substance disclosed in the specification as filed'. His Honour observed at 463-3 that the true limitation upon amendments imposed by the language of that section is that there be 'a real and reasonably clear disclosure'. Carr and Goldberg JJ at 468 accepted, without deciding, that analogy. It is the "real and reasonably clear disclosure" test is the test for fair basis (CCOM Pty Ltd v Jiejing Pty Ltd (1994) 51 FCR 260 ('CCOM'); Doric). 59 In ICI Chemicals & Polymers Ltd v Lubrizol Corp (1999) AIPC 91 91-521 at 40,017, Emmett J observed that the language of s 102(1) and s 40(3) was 'quite different' and concluded that the question of fair basis on matter described in the specification is not the same as the question of whether a specification, as amended, would claim matter not in substance disclosed in the specification as filed. 60 On appeal, the Full Court said at [118] that there is much authority for the proposition (referring to RGC and CCOM) that there is a close relationship between the test for fair basis and the question whether matter is "in substance disclosed" in a specification. The Full Court said: 'It is unnecessary to consider whether it is appropriate to go so far as to say that the two tests are "virtually the same"'. Their Honours continued: 'it will, we should think, be a rare case indeed where a claim which claims matter in substance disclosed in the specification as filed is not, equally, fairly based on the matter described in the specification (and vice versa)' (at [118]). In Merck at 421. Lockhart J seems to have taken a similar view. 61 It has now been clarified that the tests for fair basis for the purposes of s 40(3) (fair basis on the matter described in the specification) is the same test as for fair basis on matter disclosed: the requirement is of a "real and reasonably clear disclosure" such that the alleged invention as claimed is broadly, that is to say, in a general sense, described in the body of the specification (Doric at [69]). Abstract fairness plays no part in the analysis (Doric at [95]). 62 Questions of fair basis for the purposes of s 40(3) and disclosure for the purposes of s 70(2)(a) are concerned with the construction of the specification itself. On the other hand, disclosure for the purposes of novelty involves considerations of anticipation by prior art. Unlike anticipation and infringement, fair basis is not determined by looking for essential integers as if testing for infringement (CCOM at 280 and 281). 63 There is a difference in the extent of disclosure necessary to provide fair basis compared to that necessary to deprive a subsequent claim of novelty. That seems to have been accepted by the Deputy Commissioner. 64 In University of Georgia Research Foundation v Biochem Pharma Inc (2000) 51 IPR 222 ('University of Georgia'), Dr Barker as Delegate of the Commissioner of Patents discussed disclosure in the context of an originating patent containing claims to broad class of dioxolanyl nucleosides for treatment of humans infected with HIV and a subsequent application to a small group of compounds selected from that class. 65 Dr Barker considered questions of both fair basis and novelty. For fair basis, he applied the test of "real and reasonably clear disclosure". Noting, at 230, that there is no requirement for a description to exemplify every compound that is claimed, he considered the question whether what was described provided sufficient information to amount to a "real and reasonably clear disclosure" and said 'one way of looking at this would be to ask whether it is a reasonable extrapolation to go from the exemplified compounds to the compounds that are claimed'. He concluded in that case that, as the description referred to a compound of a structure similar to the compound under consideration, it was reasonable to extrapolate the method of synthesis and activity. He also held that disclosure of a general method of preparation without reason to believe that the method would not be effective was sufficient for fair basis. In University of Georgia, the evidence was sufficient to satisfy the fair basis tests raised by Dr Barker. 66 That does not mean, in my opinion and taking the principle of Roche into account, that there would be no fair basis in the absence of such satisfaction that the method would be effective. In the present case, however, the two factors identified by Dr Barker are established by the evidence. One of the exemplified compounds (example 3) differs from voriconazole only in the fluorine substituent in position 5 of the pyrimidinyl ring and, given the synthesis of example 3 Dr Stamford, as a skilled addressee, says that it would not be difficult to prepare a fluorine substituted derivative. 67 In University of Georgia,Dr Barker applied different considerations to the question of novelty. As he said at 233, 'when a citation has a disclosure in generic form (as is common in chemical patents), the question arises as to which compounds within the scope of the generic disclosure are taught to the reader' (emphasis added). He concluded that it is not enough to find that a specific compound is within the scope of the broadest disclosure of the citation: 'It is necessary to find that a reader would have understood that the specific compound was part of the technical information of the specification, and there must be an enabling disclosure of that compound'. In dealing with enabling disclosure at 237, Dr Barker observed that 'disclosure as a member of a class will not normally represent an enabling disclosure'for the purposes of anticipation unless it is 'immediately clear to the person skilled in the art how the compounds may be prepared'. 68 It is in the context of novelty that the need for a disclosure to be an enabling disclosure may become relevant. 69 In Imperial Chemical Industries Pty Ltd v Commissioner of Patents [2004] FCA 1658 ('Imperial Chemical Industries'), Crennan J considered at [64]-[68] whether an alleged anticipatory document containing a broad chemical claim encompassing many, even thousands of compounds discloses, sub silentio, a particular compound from the broad class referred to. Her Honour referred to University of Georgia at 233 and 237 and the distinction there made between 'paper disclosure' and 'enabling disclosure' as 'sound'. Her Honour was also of the view that it was in the context of novelty that the latter had relevance. 70 Implicit in the reasoning of Crennan J in Imperial Chemical Industries, is that disclosure of the broad class does disclose the members of that class. It may not be an enabling disclosure but still be a "real and reasonably clear disclosure". 71 It is not uncommon to claim a class of compounds by way of a generic formula and provision for substitutions within that formula, with exemplification of some of those compounds. The question is whether the disclosure of a class of compounds in the specification is an "in substance disclosure" of a non-exemplified compound within that class. 72 In TA Blanco White, Patents for Inventions, 4th ed., Stevens & Sons, London, 1974, the author states at 4-109, footnote 62: 'Prima facie, a general disclosure of a class is a disclosure of all members of the class, however obscure and whatever the consequences'. 73 Roche is authority for the proposition that where a large class of compounds is disclosed, claims to individual compounds forming part of that class are fairly based on the disclosure. Gibbs J held that the fact that the first basic application disclosed a class of chemical compounds, including those in the proposed claims was sufficient to provide fair basis (at 541). He rejected the submission that the compound per se should have been disclosed. 74 Further, absence of exemplification does not mean absence of fair basis (Roche at 541-542; Doric at 60. There is no requirement that each single compound be specifically claimed (Roche at 539, applying Societe Des Usines Chemiques Rhone-Poulenc v Commissioner of Patents (1959) 100 CLR 5). That is, there is a "real and reasonably clear disclosure" of that single compound by reason of its inclusion in the class. 75 There is, in my view, much to be said for the proposition that "in substance disclosure" imports a "real and reasonably clear disclosure". If there is a difference, to my mind the requirement for "in substance" disclosure is a lesser requirement than for a "real and reasonably clear disclosure" or description. Section 70(2)(a) does not require express disclosure. If it did, there would be no need for the words "in substance". It seems to me that the additional words cannot import a higher test than "real and reasonably clear disclosure". 76 However, it is not necessary for me to determine that question as in my view the evidence establishes a real and reasonably clear disclosure of voriconazole in the parent patent. Therefore "in substance" disclosure is also satisfied. I do not accept that s 70(2)(a) imports a higher test of disclosure. I note the observation in AMP Incorporated v Commissioner of Patents (1974) AOJP 3224 at 3227 regarding "in substance disclosure": 'it is not necessary before an amendment is allowed to find that the amended claim would actually fall within the scope of one or all of the other claims. It need only fall in substance within that scope.' (emphasis added) 77 In the present case, the claim is to the generic formula which, with the claimed substitutions, includes the formula for voriconazole. There is no dispute that voriconazole is, thereby, in substance within the scope of the claims. 78 In the context of the requirement to disclose a pharmaceutical substance per se, the disclosure of the class of compounds is an "in substance disclosure" of each member of the class. 79 The Deputy Commissioner proceeded on the basis that, if voriconazole were in substance disclosed in the complete specification of the patent, then an amendment could be made under s 102(1) of the Act to claim voriconazole specifically. Section 102(1) looks to whether, as the result of an amendment, the specification would claim matter not in substance disclosed in the specification as filed. This would mean that the claim to voriconazole in the selection patent would be anticipated. That, to my mind, is irrelevant to the question to be determined. 80 Voriconazole is included within the substitutions provided for in Formula I. In my view, this is a "real and reasonably clear disclosure" and an "in substance disclosure" of each of the substituted compounds so described. 81 Mr Catterns submits that, if an inventive step is required to select a compound then it has not bee disclosed. By analogy with s 102(1), he submitted that voriconazole was not "in substance disclosed" and that any amendment of the parent patent to claim the compound would not be permitted. 82 That submission has two problems. The first is that it imports into the question of disclosure in the specification considerations of inventive step. Secondly, in the present case, the evidence by way of the selection patent is not that there was an inventive step to determine the structure of voriconazole or to identify the compound per se but that there was an inventive step in determining a sub-class, of which it is a member, which has higher levels of anti-fungal activity. That evidence is irrelevant to an allowable amendment to claim the compound per se in the parent patent. 83 Mr Catterns concedes that voriconazole, as were all of the substituted compounds, was disclosed 'in a formulaic sense'. He accepts that the patentee is not limited in possible claims to those compounds specifically exemplified. His response is that the evidence of the selection patent supports an absence of "in substance disclosure" of voriconazole. For reasons I have given, I reject that submission. 84 Dr Stamford, as the skilled reader, could clearly identify voriconazole amongst the structures included in Formula I of the parent patent. It follows that the patentee could have claimed voriconazole and that such a claim would have been fairly based. So much seems to have been accepted by the Deputy Commissioner. It was that fact that he found inconsistent with the grant of the selection patent. 85 The Deputy Commissioner's reasoning was based on his consideration of the selection patent. For reasons I have given it is my view that the Deputy Commissioner erred in considering the selection patent. It was accepted by Mr Catterns that the selection patent formed an essential part of the reasoning, and, if it could not be relied upon, there would be no evidence to rebut Professor Stamford's evidence and the extension of term must be granted. 86 Accordingly, I set aside the decision of the Deputy Commissioner in this matter effective from 4 June 2004. 87 It has been agreed by the parties that, if the applicant is successful, the matter should be remitted to the Commissioner of Patents as I have no power to grant the extension sought. The matter is, therefore, remitted to the Commissioner of Patents for determination according to law. I certify that the preceding eighty-seven (87) numbered paragraphs are a true copy of the Reasons for Judgment herein of the Honourable Justice Bennett J.

Counsel for the Applicant: R J Webb SC and K J Howard

Solicitor for the Applicant: Spruson & Ferguson Lawyers

Solicitor for the Respondent: Australian Government Solicitor