The 283 patent
57 In relation to the 283 patent the respondent contended that claims 2, 3, 4 and 5 were not novel in light of the publication of:
(a) Berenson et al, Proceedings of ASCO 19:209a (2000) (Berenson 2000), except for claim 5;
(b) Sorbera LA et al, Drugs of the Future (2000) 25(3) (Sorbera 2000); and
(c) Body JJ, Clinical Research Update, Cancer 80(8): 1699-1701 (1997) (Body 1997), except for claims 3 and 5.
58 The respondent also contended that the priority date of the claims is, in any event, the filing date of the complete specification (9 May 2001) because they are not fairly based on matter disclosed in the GB priority document and thus cannot be afforded the priority given by reg 3.12(1)(b) of the Patents Regulations 1991 (Cth) (the Regulations) (which would be 19 May 2000). It followed, on the respondent's argument, that claims 2 and 3 of the 283 patent were also not novel because of matters stated in a Zometa product information sheet published on 26 November 2000. The product information sheet states:
Treatment of malignant hypercalcaemia (HCM).
Dosage/method of administration
Dosage in adults and elderly patients:
In malignant hypercalcaemia (albumin-corrected serum calcium level ≥ 3.0 mmol/l or 12 mg/dl), 4 mg Zometa is given in 50 ml 0.9% sodium chloride solution or 5% glucose solution in a 15-minute intravenous infusion…
59 As I have already noted, it is clear on the evidence that tumour-induced hypercalcaemia is a "bone metabolism disease". Claim 3 certainly treats it as such by claiming dependency on claim 2. Further, there seems little doubt, at least for present purposes, that "Zometa", as referred to in the information sheet, is zoledronic acid. Importantly, the method of administering 4mg of Zometa in a 15-minute intravenous infusion is stated. Thus, for present purposes, it is plainly arguable that the disclosure in the Zometa information sheet would anticipate claims 2 and 3 of the 283 patent. The question for present purposes is whether those claims have their asserted priority date of 19 May 2000 (thereby rendering the disclosure in the Zometa product information sheet irrelevant) or whether they have the deferred priority date of 9 May 2001 (exposing them to invalidity by reason of the prior publication of the Zometa product information sheet).
60 The concept of "fair basis" is well-understood. It is not necessary for me, for the purposes of these applications, to engage in any extended discussion of the considerations which inform the inquiry required by reg 3.12(1)(b). The relevant authorities make clear that what is required is "a real and reasonably clear disclosure" in the document on which the comparison is based, whether the document be the body of the specification (when the comparison is for s 40(3) purposes) or the document from which priority is claimed: Lockwood Security Products Pty Limited v Doric Products Pty Limited (2004) 217 CLR 274 at [69]; Synthetic Turf Development Pty Ltd v Sports Technology International Pty Ltd (2005) 67 IPR 475 at [26]. It is to be noted, however, that, for s 40(3) purposes, the comparison is expressed to be with "the matter described in the specification" whereas, for priority purposes, the comparison is expressed to be "matter disclosed in" the relevant priority document. In Leonardis v Sartas No 1 Pty Ltd (1996) 67 FCR 126 at 139 the Full Court drew attention to that distinction and observed that the absence of the definite article (in the provisions of regs 3.12(1)(b) and (c)) plainly suggests that the fair basis in question need not relate to all the matters disclosed in the priority document. There may also be significance to be attributed to the choice of the word "described" in s 40(3) and the word "disclosed" in relation to the priority provisions.
61 In CCOM Pty Ltd v Jiejing Pty Ltd (1994) 51 FCR 260 at 281 the Full Court noted Fullagar J's emphasis in Société des Usines Chimiques Rhône-Poulenc v Commissioner of Patents (1958) 100 CLR 5 at 11 that disclosure without claim is enough. In other words, it is wrong to proceed as if testing for infringement and to seek to isolate in the relevant priority document essential features of an invention that is there disclosed and to then seek correspondence between those features and the essential features of the invention as claimed in the claim under consideration. The Full Court also said that it would not be applying the statute to ask whether the earlier document fairly described the essential features of the invention as claimed in the claim under consideration.
62 A real and reasonably clear disclosure requires no more than that the alleged invention as claimed is disclosed in a general sense in the relevant document: Lockwood at [69]; Rehm Pty Ltd v Websters Security Systems (International) Pty Ltd (1988) 81 ALR 79 at 95; (1988) 11 IPR 289 at 304. As was emphasised in Lockwood at [54], the statutory language points to a comparison between the claims and what is described; it does not call for any inquiry into an inventive step or inventive merit or a technical contribution to the art.
63 The respondent sought to call in aid certain observations made by Gibbs J in F Hoffman-La Roche & Co Aktiengesellschaft v Commissioner of Patents (1971) 123 CLR 529 at 540-543, particularly the following observation at 542-543, when dealing with the question of whether certain claims were fairly based on matter disclosed in an alleged priority document:
…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 by the respondent]
64 These observations - which raise the prospect of inventive selection being priority-defeating - appear to sit somewhat discordantly with what has been said in later cases, particularly in Lockwood at [50] and [68]-[69]. Whilst a decision of a single justice of the High Court is deserving of close and respectful consideration, I am not bound by the observations quoted above. This is because, first, they are obiter dicta and, secondly, the decision in F Hoffman-La Roche is not binding on me as a matter of precedent in any event: Bone v Commissioner of Stamp Duties [1972] 2 NSWLR 651 at 654 and 664; Businessworld Computers Pty Ltd v Australian Telecommunications Commission (1988) 82 ALR 499 at 504. For the purposes of the present applications I consider myself to be bound by the statements of principle in Lockwood and will proceed accordingly.
65 The respondent contended that there is no real or reasonably clear disclosure in the GB priority document of a method that involves infusing 4mg of zoledronic acid over 15 minutes.
66 Although I have no fixed view on the matter, I am satisfied that there is a strongly arguable case that the GB priority document does in fact contain such a disclosure, for the following reasons.
67 The GB priority document identifies zoledronic acid and discloses that it has been shown in clinical tests to be a potent inhibiter of osteoclastic bone resorption leading to an effective reduction of calcium in blood levels. The GB priority document describes various aspects of the invention that is said to be disclosed. One aspect is a method of administering a therapeutically effective dose of zoledronic acid to a patient over a period less than 20 minutes. The period of "up to 15 minutes" is specifically exemplified. Another described aspect is the provision of a pharmaceutical composition said to be "adapted for the above-mentioned method". A unit dose of 4mg of zoledronate is specifically exemplified. An example is given of a clinical trial for tumour-induced hypercalcaemia in which 4mg and 8mg equivalents of zoledronic acid (delivered as a sodium salt of that acid) were diluted with 50ml of an intravenous infusion solution and then delivered to a patient over a 5-minute period, once a day. The GB priority document discloses that this period may be extended to 15 minutes if desired. The GB priority document also discloses that the method can be used for treating and preventing bone metabolism diseases including tumour-induced hypercalcaemia.
68 I am therefore satisfied that, for the purpose of the present applications, there is a strongly arguable case that, relevantly, claims 2 and 3 of the 283 patent are entitled to claim priority from the GB priority document and that their validity is not challenged by the Zometa product information sheet.
69 Insofar as the other prior art documents are concerned, I make the following observations.
70 Berenson 2000 reports on two safety and pharmacokinetic studies conducted in cancer patients with bone metastases. One study included the administration by intravenous transfusion of 4mg of zoledronic acid over 15 minutes. There is no apparent direction in that publication to infuse 4mg of zoledronic acid over 15 minutes for any particular therapeutic outcome. Moreover, there is no evidence presently before me that the studies were conducted to test efficacy. Similarly there is no evidence presently before me that efficacy is reported in the publication, although, in the course of oral submissions, the respondent suggested that some statements might be so understood.
71 It can be accepted for present purposes that Berenson 2000 literally discloses the use of 4mg of zoledronic acid administered by intravenous transfusion over 15 minutes to patients with bone metastases. The applicants, however, emphasised the context in which and purposes for which zoledronic acid was administered, namely for determining the safety and pharmacokinetics of that administration and not its efficacy. The applicants submitted that a mere literal disclosure was not sufficient to anticipate claims 2, 3 and 4, as the respondent has contended.
72 In Bristol-Myers Squibb Company v F H Faulding & Co Limited (2000) 97 FCR 524 a similar question arose. The specific question in that case was whether claimed methods of administering taxol to a patient suffering from cancer were anticipated by a series of reports of Phase I clinical trials using that substance. These reports disclosed that, in the course of the trials, doses of taxol had been administered literally according to the claims in suit. The issue was whether disclosure of that kind deprived the claimed invention of novelty. At [61] to [66] Black CJ and Lehane J reviewed a number of authorities and (at [67]) said:
What all those authorities contemplate, in our view, is that a prior publication, if it is to destroy novelty, must give a direction or make a recommendation or suggestion which will result, if the skilled reader follows it, in the claimed invention. A direction, recommendation or suggestion may often, of course, be implicit in what is described and commonly the only question may be whether the publication describes with sufficient clarity the claimed invention or, in the case of a combination, each integer of it. But in this case medical practitioners hardly needed to be told that it was possible to infuse a particular dose of taxol over three hours, or how to do it. Nor, equally obviously, is that the point of the claims. The claims of the earlier of the petty patents are for a method for administration of taxol to a patient suffering from cancer; the claims of the later one are for a method of treating cancer. In each case the method involves a particular regimen for the infusion of taxol. The context was that great difficulties had been encountered in using taxol, despite its known anti-carcinogenic properties, in the treatment of cancer, because of the drug's side effects. Each of the trials reported in the articles referred to was an investigation directed towards finding a solution of the difficulties: directed, particularly, to ascertaining safe dosage levels. But, though methods falling within the claims of the patents were used in each trial, none of the reports can be said to teach (a word which in this context encompasses direct, recommend and suggest) that which the petty patents claim.
73 At [68] their Honours concluded:
… The question is still, what does the prior publication teach? Each of the reports taught, no doubt, some useful things relating to the administration of taxol. But none of them taught the method of the claims.
74 The applicants submitted that the same conclusion is warranted in the present case.
75 The applicants also advanced the proposition in oral submissions that the validity of the claims of the 283 patent might not be affected by Berenson 2000 because of the operation of s 24(1) of the Act and regs 2.2 and 2.3 of the Regulations. In particular the applicants referred to the possibility that Berenson 2000 was a publication by at least some of the inventors that was read before a learned society or published by such a society with their consent. I place no weight on that submission. I do not consider that, in its present state, the evidence permits me to draw any conclusion, provisional or otherwise, about whether the applicants have the benefit of those provisions.
76 Sorbera 2000 reports on clinical trials using a range of doses of zoledronic acid from 0.024mg to 8mg, infused over various periods, for the treatment of various bone metabolism diseases. The results of these trials are reported in various boxes which disclose the methods of treatment given. The document discloses that zoledronic acid was administered only as a 5-minute infusion or as a 30-minute infusion. Box 6 reports on a Phase 1 trial of zoledronic acid in patients with osteolytic bone metastases. Various doses were given intravenously, ranging from 0.1mg to 8.0mg. Zoledronic acid was reported as safe and effective in these patients. Importantly the subtext to Box 6 states that the zoledronic acid was administered as a "5-30 min infusion once monthly for 3 months". When dealing with that trial, the publication states:
A phase I trial in 59 patients with osteolytic bone metastases (e.g., multiple myeloma, breast cancer) showed that zoledronate may be safely administered as short monthly i.v. infusions (0.1, 0.2, 0.4, 0.8, 1.5, 2, 4 and 8 mg for 3 months). Thirty-minute infusions of the low doses (0.1-0.2 mg) were well tolerated although higher doses were well tolerated when given as 5-min infusions…
77 The respondent relied on the evidence of Dr Hosking that the subtext to Box 6 revealed a time period of 5 to 30 minutes. However, the above quoted passage clearly indicates that only 5-minute and 30-minute infusions were given and that 4mg of zoledronic acid was given as a 5-minute infusion. It is not of course necessary for me to resolve any debate on the evidence. It is sufficient for me to note that there is, to say the least, a real and substantial doubt that this publication discloses a method of treatment in which 4mg of zoledronic acid was administered intravenously over a period of 15 minutes or at least discloses that method with sufficient clarity and precision so as to be novelty-destroying.
78 Body 1997 reports on two Phase I clinical trials using zoledronic acid. The first involved dosages in the range of 1.2 and 2.4mg for an average 60kg individual. The publication discloses that this dosage was administered as a single 20-minute infusion. The second clinical trial was with patients with lytic bone metastases. The abstract states that zoledronic acid was given as monthly short infusions (5-30 minutes) at doses between 0.1-8.0mg. However, when this trial is discussed in more detail in the publication, the following is stated:
An open-label dose-ranging trial of rapid (5-minute) intravenous infusions of zoledronate then was conducted in normocalcemic patients with osteolytic bone metastases (ref. 4 and Novartis, personal communication). Evaluated doses ranged from 0.1-8 mg (0.1, 0.2, 0.4, 0.8, 1.5, 2, 4 and 8 mg) and the infusions were repeated 3 times at 4-week intervals. The study included 58 patients, 6-10 per dose level, mainly with multiple myeloma (n = 36) or breast carcinoma (n = 19)…
79 The respondent once again called in aid evidence given by Dr Hosking that this publication discloses that zoledronic acid was given over 5 to 30 minutes at monthly intervals. However, the more detailed description quoted above plainly indicates that the period of infusion was, specifically, 5 minutes. The applicants' witness, Dr Murray, saw the document as only disclosing a 5-minute infusion in relation to this trial. There is, therefore, a real and substantial doubt that this publication discloses a method of treatment in which 4mg of zoledronic acid was administered intravenously over a 15-minute period or at least discloses that method with sufficient clarity and precision so as to be novelty-destroying.
80 On the present state of the evidence I am not persuaded that any of the three publications necessarily anticipates the relevant claims of the 283 patent. I have referred to some of the matters of substance which would militate against a finding that one or more of them does anticipate one or more of the relevant claims. I accept that, at a final hearing, the debate on these matters may well be subjected to greater scrutiny by the parties. However, at the present time, I am not persuaded that, on novelty grounds, the prima facie case of infringement of the 283 patent established by the applicants is a weak one, as the respondent has contended.
81 The respondent's challenge to the validity of the claims on the basis that they do not involve an inventive step has two aspects. First, the respondent contended that the claims do not involve an inventive step when seen against the backdrop of the common general knowledge of the person skilled in the art. Secondly, the respondent contended that the claims do not involve an inventive step when seen against the backdrop of the common general knowledge combined with Berenson 2000, Sorbera 2000 and Body 1997, considered separately: see s 7(2) and (3) of the Act.
82 The issue presented on this aspect of the respondent's case on invalidity is whether the person skilled in the art would be directly led as a matter of course to try the claimed invention in the expectation that it might well produce a useful alternative to, or better method of treatment than, the existing methods of treatment using bisphosphonates: Aktiebolaget Hässle v Alphapharm Pty Limited (2002) 212 CLR 411 at [53].
83 The gravamen of the respondent's case on obviousness in respect of claims 2, 3, 4 and 5 of the 283 patent was that, given what was commonly known by the person skilled in the art about the administration of bisphosphonates, and zoledronic acid in particular (especially its relative potency over other bisphosphonates which would suggest that it could be administered in lower doses over shorter periods of time than other bisphosphonates), then, if toxicity is a problem, the person skilled in the art would have been directly led as a matter of course to conduct a dosing trial which would include the administration of 4mg of zoledronic acid in an intravenous infusion over 15 minutes in the expectation that it might well provide a therapeutic result for patients in need of bisphosphonate treatment.
84 The applicants contended that the respondent's approach proceeds upon an incorrect application of principle and, in any event, is based on propositions which are, at least, controversial.
85 As to the first of these matters, the applicants submitted that the respondent's approach to determining obviousness advocates a "worthwhile to try" approach which was rejected in Hässle: see Hässle at [66]-[76].
86 As to the second of these matters, the applicants submitted that:
(a) It does not follow from higher potency that shorter infusion would be appropriate because the infusion period would depend upon toxicity which was unknown for zoledronic acid, and renal side effects were known to be a difficulty with the infusion of bisphosphonates over shorter infusion times (for example, with 30 minutes for pamidronate).
(b) The proposition that the duration of infusion and the inter-dose interval could be predicted from drug potency is negated by the data on pamidronate, ibandronate, risedronate, alendronate, clodronate and zoledronate.
(c) The potential significance of differences in affinity of bisphosphonates for bone was not known and did not become a feature of the literature until four to five years after the priority date.
(d) Neither an efficacious dose of a new bisphosphonate like zoledronic acid nor its adverse effect profile could be predicted. They could only be ascertained by testing.
87 For its part the respondent submitted that the applicants' evidence relevant to this issue, and led through Dr Murray, raised the bar too high and showed that the applicants themselves were proceeding on an incorrect application of principle.
88 There are difficulties in attempting to deal, in the context of an application for interlocutory injunctive relief, with competing factual propositions of the kind advanced by the parties in the present case. Such propositions have not been tested as they would be at a hearing for final relief; nor have they been subjected to the stringency of analysis that one would expect at such a hearing. The best that one can reasonably do is to acknowledge that the present state of the evidence clearly discloses a substantial legal and factual dispute between the parties which is inconclusive.
89 For example, Dr Hosking's evidence, on which the respondent specifically relied, rises no higher than that it was "not unexpected" that zoledronic acid administered over 15 minutes offers a safety advantage in terms of renal tolerability over shorter infusion times. This statement does not appear to say anything about therapeutic efficacy. In its present form that evidence is also retrospective in character. Dr Hosking's evidence was also that, if faced with the problem of renal tolerability, he would expect endocrinologists to investigate longer infusion times with the expectation of increased renal safety. This evidence, on its face, says nothing specifically about what the longer infusion times would be.
90 I would add that, in light of the particular issues raised by the applicants as to why the invention as claimed is not obvious, I do not think that the respondent's reliance on the three publications, assuming them to satisfy the requirements of s 7(3) of the Act, materially advances its position for the purposes of challenging the strength of the prima facie case established by the applicants.
91 In sum, I am not persuaded that, on obviousness grounds, the prima facie case of infringement of the 283 patent established by the applicants is a weak one, as the respondent has contended.
92 I should add that the applicants placed reliance on the fact that the 283 patent had undergone re-examination under s 97 of the Act and that the Commissioner of Patents had concluded that, first, claims 1 to 15 were fairly based on the GB priority document and that, secondly, the invention as claimed in each of those claims was both novel and inventive. The prior art considered by the Commissioner in reaching those conclusions included Sorbera 2000 and Body 1997.
93 The respondent submitted that, in undertaking a re-examination under s 97, the prior art base on which the Commissioner relies is limited by s 98(2) of the Act. In any event, the Commissioner did not consider Berenson 2000. Moreover, a re-examination is not conducted in the same way as contested proceedings in this Court.
94 I accept those submissions. Nevertheless, re-examination under the Act is conducted by an expert body and the conclusions expressed in the Commissioner's report provide, at this level of inquiry, some measure of support for the validity of the claims presently relevant, at least in so far as the correct priority date of the claims, and the challenge to them on novelty grounds based on Sorbera 2000 and Body 1997, are concerned. Having said that, I have reached my provisional views about the respondent's limited challenge to validity independently of the conclusions expressed by the Commissioner.