Mylan Health Pty Ltd V Sun Pharma Anz Pty Ltd [2020] FCAFC 116
Mylan v Sun Pharma is the latest word from the Full Federal Court on the infringement of Swiss-style claims, novelty, inventive step and fair basis. Before the Full Court was three patents relating to fenofibrate, a drug used to treat cholesterol and diabetic retinopathy in patients with type 2 diabetes. The three patents related to (1) the use of fenofibrate to treat diabetic retinopathy (Treatment Patent), (2) fenofibrate compositions comprising fenofibrate in nanoparticulate form and with a surface stabiliser (Nanoparticle Patent) and (3) an immediate-release fenofibrate composition with micronized fenofibrate and a hydrophilic polymer that produced a desired dissolution profile (Dissolution Patent). All three patents were found invalid, and the Swiss-style claims not infringed, at first instance. The Full Court upheld that decision.
Swiss-Style Claims
Swiss-style claims require the use of a therapeutic substance to manufacture a pharmaceutical product (often referred to as a “medicament”) for the treatment of a condition. The Treatment Patent claimed the use of fenofibrate for the manufacture of a pharmaceutical product for treating diabetic retinopathy. Pharmaceutical products that can be used to treat multiple conditions, with some but not all conditions claimed by the patent, raise difficult questions as to the circumstances in which the exploitation of that product infringes a Swiss-style claim.
The Full Court explained that the question of infringement of a Swiss-style claim depends on whether the product is “for” the claimed therapeutic purpose and that that question must be answered by reference to the characteristics of the product (as opposed to the manufacturer’s intention). The most important characteristics are the products formulation, dosage, packaging and labelling. That said, the manufacturer’s actual intention in making the product and the reasonably foreseeable uses to which that product will be put might still be relevant (albeit not determinative). Where a product will be used “extensively” for purposes that fall outside the Swiss-style claim, the fact that it is reasonably foreseeable, or even likely, that a substantial portion of the product would also be used for the claimed therapeutic purpose is not determinative of infringement. The Full Court thus confirmed that it is easier to establish infringement of a method of treatment claim than a Swiss-style claim.
The generic product in suit was found not to infringe the Swiss-style claims of the Treatment Patent primarily because they were not indicated for diabetic retinopathy. It was not enough that the innovator product did include that indication, that the generic product was bioequivalent to the innovator product and that the labelling of the generic product contained no explicit disclaimer against its use for treating diabetic retinopathy. Although not considered by the Full Court, it is worth noting that the primary judge held that the Treatment Patent’s method of treatment claims would have been infringed (had they been found valid). The Full Court’s decision thus demonstrates that Swiss-style claims provide a patentee a narrower scope of protection than method of treatment claims.
Novelty
The Treatment Patent lacked novelty in light of a prior art protocol that included a hypothesis that administering a fibrate with a statin would reduce the rate of development or progression of diabetic retinopathy compared to administering only a statin. The Full Court considered that the publication of this hypothesis was sufficient to anticipate the Treatment Patent, even though it was expressed as a hypothesis that required testing, and the prior art disclosed no data to verify that the hypothesis might be correct. The Full Court pointed out that a patent need not include scientific proof or substantiation, and no greater requirement is imposed on a prior documentary disclosure in order for it to be anticipatory. Accordingly, a speculative statement in the prior art can anticipate a patent. As the Full Court stated, “what is required is that the prior art document discloses that which is subsequently claimed as an invention”.
Inventive Step
With respect to inventive step, the Full Court offered more clarification than transformation as to the state of the law, although it continues a recent trend of the court holding patents to a higher standard on obviousness and more readily finding a lack of inventive step.
The Full Court confirmed that an invention cannot be obvious merely because it was “worth a try” at the priority date. The person skilled in the art (PSA) must be directly led to the invention with the expectation that it might well be useful in light of the common general knowledge and any relevant prior art. However, it is not necessary that the PSA believe that there is a better than 50% chance of success. The Full Court declined the opportunity to identify the level of expectation required to satisfy the inventive step case, saying that the requisite level of expectation depends on the circumstances.
“In the context of s 7(2) of the Act, the legal standard, expressed by the word ‘obvious’, is a flexible and indeterminate standard which poses a question of fact to which there is often, perhaps usually, no single, right answer.” Thus in answering the question whether an invention is obvious, an evaluative judgment is called for and, in order to answer the question affirmatively, the Court must be persuaded that the invention, as it is claimed, is indeed obvious. As a general proposition, reasoning to such a conclusion is not assisted by a percentage-based analysis.”
As a result, the line between a sufficient expectation of success and “worth a try” remains elusive.
The Treatment Patent was held obvious in light of second prior art publication that disclosed the results of a clinical trial suggesting that a reduction of elevated serum lipid levels may help prevent vision loss associated with diabetic retinopathy. The publication did not specifically test whether the use of a lipid-lowering agent (like fenofibrate) would be useful for treating diabetic retinopathy. Further, the scientific method employed by the publication was imperfect, leading to some minor doubts as to the significance of its observations. However, the Full Court adopted a practical approach when interpreting the publication and considered that these imperfections did not raise enough doubt as to the likelihood of success to render the Treatment Patent inventive.
Similarly, in relation to the Nanoparticulate Patent, doubts expressed by witnesses as to the likelihood of the claimed formulations being useful (one witness described trying the invention as a “gamble”, and that he could not be sure that it would work) were not enough to support a finding that its claims were inventive. The Full Court was also unperturbed by the need to conduct some experimentation in order to implement the invention, characterising that work as routine optimisation and trial and error.
The Full Court’s decision suggests that it will be more difficult to establish inventiveness based on a lack of expectation of success. Instead, a patentee defending an obviousness case may be better served by providing reasons for why the PSA would not be directly led to try the invention, or that the path from the prior art to the invention would require inventive work as opposed to routine trial and error.
Fair Basis
The Dissolution Patent included a claim to a fenofibrate composition with a specified dissolution profile. The Full Court, applying well-established principles, found this claim lacked fair basis because, although the specification included references to compositions with the specified dissolution profile, those compositions also contained micronized fenofibrate. There was thus no “real and reasonably clear” description of compositions with the specified dissolution profile per se.
The Full Court’s decision is a further reminder of the importance, when claiming an invention by reference only to the results that it achieves (as opposed to the means of achieving those results), of drafting the specification carefully to ensure that it is clear that the invention disclosed in the patent includes achieving that result by any means.