The question of infringement
130 Apotex contends that the primary judge erred in concluding that, based on s 117 of the Patents Act, it threatened to infringe the patent because of its intended supply of its leflunomide product called Apo-Leflunomide.
131 The case on infringement turns on the proper construction and application of s 117 in light of the findings of fact made by the primary judge. The case for infringement was based on s 117 because Apotex, itself, was not intending to use Apo-Leflunomide in the claimed method but to be a supplier of that product in circumstances where, according to Sanofi-Aventis, the use of that product to treat psoriasis would infringe the claim in suit.
132 Section 117 of the Patents Act provides:
(1) If the use of a product by a person would infringe a patent, the supply of that product by one person to another is an infringement of the patent by the supplier unless the supplier is the patentee or licensee of the patent.
(2) A reference in subsection (1) to the use of a product by a person is a reference to:
(a) if the product is capable of only one reasonable use, having regard to its nature or design - that use; or
(b) if the product is not a staple commercial product - any use of the product, if the supplier had reason to believe that the person would put it to that use; or
(c) in any case - the use of the product in accordance with any instructions for the use of the product, or any inducement to use the product, given to the person by the supplier or contained in an advertisement published by or with the authority of the supplier.
133 The prefatory condition in s 117(1) - "(i)f the use of a product by a person would infringe a patent" - requires particular attention. The "use" to which it refers is given meaning and content by s 117(2), which directs attention to the circumstances posited by each of paragraphs (a) to (c). Each of these paragraphs is directed to a discrete inquiry that is to be undertaken to determine whether there is a "use of a product by a person" within the stated requirements. If so, it is that "use" by that "person" which gives content to the prefatory condition in s 117(1). Section 117(1) then proceeds by asking whether that use by that person would infringe the patent in suit. If so, s 117(1) is then meaningfully engaged with the consequence that the supply of the product, by one person to another, will itself be an infringement of the patent, unless the supplier is the patentee or a licensee of the patent.
134 The issues that fall for consideration on appeal are whether the primary judge erred in finding that s 117(1) was engaged by the application of ss 117(2)(b) and (c). Before turning to deal with those issues it is necessary to refer to another aspect of the way in which Apotex's appeal was argued.
135 Apotex put to the forefront of its appeal on this question the contention that, in the circumstances of this case, the relevant use for the purposes of s 117(1) was the use of Apo-Leflunomide to treat PsA. It contended that that use would not infringe the claim. Thus, it argued, the prefatory condition of s 117(1) could not be satisfied, with the result that there could be no infringement by it under that provision.
136 This approach misapplies s 117(1) by positing the wrong use and, as a consequence, asking the wrong question. The question is not whether the use of Apotex's leflunomide product to treat PsA would infringe the claim in suit, but whether the use of Apotex's product in one of the ways mentioned in ss 117(2)(b) and (c) would infringe.
137 Apotex accepted that the use of its leflunomide product to treat psoriasis or, to put it in the words of the claim, its use as a method of treating psoriasis, would infringe the claim. Thus if, on the facts of this case, one of the uses in ss 117(2)(b) or (c) is the use of Apo-Leflunomide to treat psoriasis, Apotex's supply of that product will infringe the patent. Attention must be directed, therefore, to the correctness of the primary judge's findings of fact regarding the application of ss 117(2)(b) and (c) in the present case.
138 In that connection, the primary judge considered, first, the application of s 117(2)(c) of the Patents Act. Fundamental to that consideration was Apotex's product information document that had been provided to the TGA. The document contained the following statement of indications:
INDICATIONS
Apo-Leflunomide is indicated for the treatment of:
• Active Rheumatoid Arthritis
• Active Psoriatic Arthritis. Apo-Leflunomide is not indicated for the treatment of psoriasis that is not associated with manifestations of arthritic disease.
The combined use of Apo-Leflunomide with other Disease Modifying anti-Rheumatic Drugs (DMARDS) has not been adequately studied (see PRECAUTIONS).
139 Given that the evidence established that:
(a) psoriasis is a diagnostic criterion of PsA;
(b) nearly every person with PsA has or will develop psoriasis; and
(c) the administration of leflunomide to a person with PsA will treat that condition and also treat psoriasis (if a person presents with psoriasis) or prevent psoriasis (if that person would have developed psoriasis),
the primary judge reasoned and found that, because the Apotex product information instructs rheumatologists to use Apo-Leflunomide for the treatment of PsA, it necessarily instructs rheumatologists to use the product to treat psoriasis, independently of the express reference to psoriasis in the document.
140 However, separately from that reasoning and finding, the primary judge found that Apotex did give instructions in the product information document to use Apo-Leflunomide for the treatment of psoriasis, by the statement: "Apo-Leflunomide is not indicated for the treatment of psoriasis that is not associated with manifestations of arthritic disease", where appearing in the passage quoted above.
141 In this connection Apotex argued before the primary judge that the use of the double negative in this statement could not be transformed into a positive instruction. Apotex advanced the same argument on appeal.
142 The primary judge rejected that argument. She found that it contradicted the ordinary meaning to be given to the statement. It was also inconsistent with the undisputed medical evidence about the relationship between PsA and psoriasis: see at [262].
143 We are not persuaded that the primary judge erred in the conclusion to which she came. We are satisfied that it was open to her Honour to find that the statement of indications contained the instruction to use Apo-Leflunomide to treat psoriasis.
144 In this connection Sanofi-Aventis, on appeal, also drew attention to a part of the Apotex product information that immediately preceded the statement of indications we have quoted. That part reported on an analysis of patients treated with leflunomide who were assessed by reference to the Psoriasis Area and Severity Index (PASI). This index is used as a measurement of the efficacy of treatment for psoriasis, not PsA. In the reported analysis, patients were assessed to reflect changes following the administration of leflunomide in the extent and severity of psoriasis lesions as judged by erythema, desquamation, and infiltration. The analysis reports that leflunomide resulted in a significant improvement in PASI scores over a 24-week study relative to placebo.
145 The primary judge did not refer to this part of the Apotex product information when arriving at her finding as to what the quoted passage instructed practitioners to do. In our view it was not necessary for her Honour to do so, although we do note that her Honour specifically referred to the PASI analysis when considering whether Apotex had reason to believe that the persons to whom it wished to supply its product (relevantly, rheumatologists) would put it to an infringing use. Be that as it may, we are satisfied that Apotex's statement of indications alone provided a sufficient basis for her Honour's finding under s 117(2)(c). The reporting in the product information of the PASI analysis provides additional matter that fortifies that finding.
146 Apotex accepted that if no error was demonstrated in relation to the primary judge's findings in relation to the application of s 117(2)(c), then s 117(1) was correctly engaged against it. It follows, therefore, that Apotex's appeal, insofar as it concerns the question of infringement based on s 117(1) of the Patents Act, cannot succeed.
147 We propose, however, to also consider the second basis on which the primary judge found s 117(1) to be engaged. At trial there was an issue as to whether Apo-Leflunomide was a staple commercial product within the meaning of s 117(2)(b). The primary judge found (at [270]) that it was not a staple commercial product. There is no appeal from that finding. The inquiry under the specific requirements of s 117(2)(b) was thereby engaged: did Apotex have reason to believe that Apo-Leflunomide would be used to treat psoriasis?
148 The primary judge reasoned (at [263]) that, given the instruction in the Apotex product information with respect to the treatment of psoriasis, Apotex had reason to believe that a rheumatologist prescribing Apo-Leflunomide to a patient would in fact put it to that use. In our view, no error is disclosed in that reasoning. Her Honour's finding was also plainly supported by the evidence.
149 In that connection, Professor Brooks, who was called by Apotex, was cross-examined on this subject. His evidence was that, as a rheumatologist treating a patient presenting with concurrent PsA and psoriasis, he would administer leflunomide with the treatment of both conditions in mind. The primary judge (at [51]) quoted various passages from the transcript of Professor Brooks's oral evidence, including the following:
Even now, however long after it is from 1993, perhaps if I take you to the date you swore your first affidavit, would still describe your knowledge of psoriasis as being a basic knowledge of psoriasis? Yes, in terms of being able to diagnose it and treat it.
…
And so it was acceptable, in fact, in 1993, for a rheumatologist to have a basic knowledge of psoriasis? Well, it depends what you define as a "basic knowledge". I would expect rheumatologists to know more than be able to spell the condition. Because they are dealing with making a diagnosis of psoriatic arthritis, they need to be able to diagnose it almost as well as a dermatologist, and they need to be able to treat it almost as well as a dermatologist.
…
… I think that, as I said, rheumatologists need to know about psoriasis probably more than most other specialties apart from dermatologists, because they are dealing with a disease that crosses those two boundaries.
…
Not the way it is written there, really. I mean, as I have just said, rheumatologists have to be able to diagnose psoriasis and know basically how to manage it, because otherwise how can they treat psoriatic arthritis?
Sorry, the diagnosis of psoriasis is effectively a key part of the diagnosis of psoriatic arthritis? Absolutely.
150 This evidence supports the findings made by the primary judge that have been quoted above, namely that:
(a) a rheumatologist treating a patient with PsA will know how to treat the patient's psoriasis as part of the treatment of PsA, either independently or in consultation with the patient's dermatologist if the patient is also under the care of a dermatologist: see [129]; and
(b) if leflunomide is administered to a patient with PsA by a rheumatologist, that administration would be expected by the rheumatologist to prevent or treat the patient's psoriasis, to some extent at least: see [130].
151 Professor Smith, who was called by Sanofi-Aventis, was also cross-examined about the use of leflunomide by rheumatologists in the treatment of psoriasis. The primary judge (at [43]) quoted various passages from the transcript of his evidence, namely:
…the question is asking me how effective is leflunomide in psoriasis, and I can't answer that because I'm not a dermatologist and I don't treat psoriasis except when it is in the situation of psoriatic arthritis, and, even then, I'm treating the psoriatic arthritis; I'm not treating the psoriasis. So I can't really honestly answer that question.
When you say, even then, you are not treating the psoriasis, you are treating the psoriatic arthritis - I think that is what you said? Yes.
You mean you are administering the, let's say, leflunomide for the purpose of treating psoriatic arthritis in that case? Correct.
The joint disease? Yes.
And if it has a benefit, as the TOPAS study suggests, in relation to the patient's dermatological disease, that's an incidental benefit? I am certainly pleased with the result for the patient, but that is not my primary aim of treating the patient.
152 This evidence reflects differences in opinion and clinical approach between Professor Brooks and Professor Smith. The fact that these differences exist does not mean, however, that the primary judge's findings as to Apotex's "reason to believe" were in error.
153 Apotex also relied upon her Honour's finding that dermatologists do not prescribe leflunomide for the treatment of psoriasis alone. That reliance, however, is really beside the point once it is accepted that rheumatologists (even if not all rheumatologists) will prescribe leflunomide to treat PsA and psoriasis in patients presenting with concurrent conditions.
154 In oral argument Apotex submitted that the primary judge's finding - that it had reason to believe that the person to whom its product would be supplied would put it to use for the treatment of psoriasis - was based on reasoning limited to the finding that administration of leflunomide to treat PsA would inevitably treat or prevent psoriasis, and not one more broadly based that involves the purpose for treatment of psoriasis as such. We do not read her Honour's findings as being so limited. Indeed, Apotex's product information - effectively stating that its intended leflunomide product was indicated for the treatment of psoriasis associated with manifestations of arthritic disease - cannot be read as an arid instruction that is unrelated to an acknowledged reality that rheumatologists, like Professor Brooks, do seek, and will seek, to treat both conditions when patients present with PsA and psoriasis concurrently.
155 It follows, in our view, that the primary judge's findings with respect to the application of s 117(2)(b) provide an independent foundation to engage the application of s 117(1) in the present case.
156 Accordingly, this ground of appeal fails.