Clinical trial protocols anticipate method of treatment claims, and further clarity provided on construction of Swiss-style claims

Australia’s Full Federal Court recently delivered judgment in an appeal in a significant patent case: Mylan Health Pty Ltd v Sun Pharma ANZ Pty Ltd [2020] FCAFC 116.  The case concerned three patents relevant to Mylan’s oral lipid-lowering agent, Lipidil® (fenofibrate).

 

An enlarged Full Court bench comprising 5 judges (Middleton, Jagot, Yates, Beach and Moshinsky JJ) was appointed to hear and decide Mylan’s appeal.  This was because Mylan sought to clarify the Full Court’s previous statement in Merck & Co Inc v Arrow Pharmaceuticals Ltd [2006] FCAFC 91; 154 FCR 31 that the characterisation of an alleged anticipation as a “suggestion” in relation to the invention, is “not necessarily fatal to a novelty argument”.  Mylan submitted this statement by the Full Court did not countenance “mere speculation” or “the presentation of no more than a reasoned hypothesis” as an anticipatory disclosure.  On this basis, Mylan submitted to the Full Court (unsuccessfully, as explained below) that the trial judge (Nicholas J) had erred in finding that a hypothesis stated in a prior art document relating to a clinical study deprived methods of treatment claims of novelty.

The Full Court’s decision also provided important guidance in relation to the approach taken by Australian courts in considering obviousness, the construction and infringement of ‘Swiss-style’ claims under Australian patent law and the extent to which consistory clauses alone can provide fair basis for a claim.

Method of treatment and Swiss-Style claims lack novelty in light of clinical trial protocol

The Full Court considered whether method of treatment and Swiss-style claims could be anticipated by prior art comprising a protocol for a clinical trial of the claimed method.

Mylan argued that such a protocol could not be novelty-defeating, because at most it identified a hypothesis that required testing, and could not be understood as teaching or recommending that the claimed method be put to clinical use.  The Full Court rejected that analysis and upheld the trial judge’s finding that Mylan’s method of treatment and Swiss-style claims lacked novelty.

The Full Court held that, in assessing novelty, the key question is whether the information disclosed in the prior art is sufficiently specific and complete to be equal to the invention that is later claimed.  If so, then even a protocol for a trial to test the claimed method could be novelty-defeating.  The Full Court acknowledged that, in this respect, Australia’s law on novelty differs from the law applied by UK courts in cases such as Regeneron Pharmaceuticals Inc v Genentech Inc [2012] EWHC 657 (Pat) and Hospira UK Limited v Genentech Inc [2015] EWHC 1796 (Pat), which hold that the prior art must disclose actual achievement of the relevant therapeutic effect to be novelty-defeating.

This aspect of the Full Court’s decision arguably fails to give due consideration to the proper meaning and importance of words such as “treat” and “prevent” in method of treatment and Swiss-style claims.  As Mylan contended, at the stage of disclosing the protocol for a clinical trial, it is not known whether the product or method under consideration does in fact “treat” or “prevent” the particular condition or illness of interest, and there is a significant prospect that it will later prove ineffective or unsafe.  The approach of the Full Court and the primary judge makes clear that the nature and extent of the prior-published clinical trial protocol or other document will be critical in each case.  Those case-specific factual issues will be especially important in future cases, as it would seem a harsh outcome for patentees for statements of unproven hypotheses, theories, ideas or suggestions to anticipate and invalidate (for lack of novelty, putting aside considerations of obviousness which depend on the common general knowledge and availability of prior art) claims to a method that the patentee has subsequently proven effective and safe in “treating” or “preventing” the particular condition or illness.

Obviousness of formulation and method of treatment claims

Australian Courts generally assess obviousness by asking whether, before the priority date, a skilled person presented with the same problem as the patent owner would have been “directly led to try the claimed subject matter with a reasonable expectation of success” (referred to as the “modified Cripps question”).  Historically, that test has been applied in a strict manner by Australian courts, leading a number of patents to be upheld in Australia that have been invalidated on obviousness grounds in other jurisdictions.

Recently, however, Australian courts have adopted a more flexible interpretation of the Cripps test.  This Mylan case continues that trend.  The trial judge held two of Mylan’s patents (one relating to nanoparticulate formulations of fenofibrate, the other relating to methods of preventing or treating retinal damage associated with diabetes by administering fenofibrate) invalid on obviousness grounds, and the Full Court upheld those findings.

The following aspects of the Court’s obviousness analysis are notable:

  • Mylan’s patent for a nanoparticle formulation of fenofibrate included claims which required the use of specified surface stablizers.  The trial judge did not find that the skilled person would have been directly led to select those specific stabilizers with an expectation that they would be effective. Rather, he found that the claimed stabilizers were logical to try and that routine, trial-and-error testing would have demonstrated their suitability.  The Full Court agreed this was sufficient to support an obviousness finding.
  • In relation to Mylan’s method of treatment patent, an expert gave evidence that, before the priority date, his expectation of success with the claimed method would have been less than 50%.  The trial judge held that evidence was not inconsistent with a finding of obviousness, because the Cripps test does not require a numerical assessment.  Again, the Full Court agreed with that analysis.

The test for obviousness applied by Australian courts remains more demanding upon the party seeking revocation than the approach taken by (for example) the European Patent Office or the UK courts.  However, the Mylan decision continues a trend in Australian patent cases towards a more flexible application of the obviousness test that is somewhat closer to the approach taken by the European Patent Office and UK courts.  This serves to emphasise the importance of careful preparation of the obviousness defence in close collaboration with inventors and key expert witnesses.

Defining the scope of Swiss-style claims

The claims asserted by Mylan included Swiss-style claims.  Swiss-style claims are typically drafted in the form “Use of [active ingredient] in the manufacture of a medicament for the treatment of [disease or disorder]”.  They came about from the need to satisfy particular requirements for patentability which formerly applied under the European Patent Convention.  Although these requirements do not exist in Australia, Swiss-style claims are routinely included in Australian patents as their scope is different from that of method of treatment claims, which are also permitted under Australian law.

The Full Court in this Mylan case examined the interpretation of Mylan’s Swiss-style claims, having regard to the decision of the UK Supreme Court in Generics (UK) v Warner-Lambert [2018] RPC 2, and provided guidance on determining the scope of such claims under Australian law.

One of the Swiss-style claims asserted by Mylan recites:

 “Use of fenofibrate or a derivative thereof for the manufacture of a medicament for the prevention and/or treatment of retinopathy, in particular diabetic retinopathy”.

The Full Court confirmed that the claim, if valid, conferred a monopoly in respect of the method or process of making the medicament, and that the method or process is complete upon manufacture.  The monopoly did not extend to a method of treatment – that being the province of method of treatment claims.  The Full Court also confirmed that Swiss-style claims are purpose-limited in the sense that the medicament resulting from the method or process is characterised by the therapeutic purpose for which it is manufactured, as specified in the claim.  The Full Court rejected the “outward presentation” test that was favoured by Lords Sumption and Reed in the UK Warner-Lambert case.

In the first instance decision, the primary judge said that the the crucial question concerning the infringement of a Swiss-style claim was whether the manufacturer had made or will make the medicament with the intention that it be used in the treatment of the designated condition.  On this basis, to prove infringement of a Swiss-style claim, it would not be enough to show that it was “reasonably foreseeable” that a generic product would be put to the use referred to in those claims (although foreseeability could be relevant in the overall analysis).  The trial judge held that, to prove infringement of Swiss-type claims, it would be necessary to show that the generic intended that its product be put to the use referred to in the Swiss-style claims.

The Full Court disagreed with this approach, instead finding that infringement of a Swiss-style claim is concerned with what the allegedly infringing manufacturer has done, not what it intended to do.  That is, not what a generic manufacturer intended, but what the generic product is for.  According to the Full Court, a single factual question arises when considering infringement:  as the product of the claimed method or process, is the medicament for the specified therapeutic purpose?  The question, the Full Court said, is answered having regard to “all the circumstances of the case”.

The Full Court pointed to several such “circumstances” that will be relevant in determining the therapeutic purpose of the medicament as defined by a Swiss-style claim.  First, the court noted that the physical characteristics of the medicament as it emerges as a product of the manufacturing process, including its formulation and dosage, packaging and labelling, and its patient information, will be an important consideration.  So too will evidence of the manufacturer’s actual intention in making the medicament, where such evidence is available.  Both factors are relevant considerations, but neither is determinative.

On the facts of this case (which included “skinny labelling” confining the approved indications of the generic product to indications outside the conditions within Mylan’s method of treatment claims), the Full Court held that Mylan had not proved that Sun’s fenofibrate products were “for” the second medical use covered by Mylan’s Swiss-type claims.

The Full Court also gave consideration to the reasonably foreseeable use or uses to which the medicament would be put after manufacture.  But while a reasonably foreseeable use may be relevant in deciding the therapeutic purpose of a medicament, it is also not determinative:  it might be reasonably foreseeable that a product might be put to a particular use, but it does not necessarily follow that the product, as manufactured, is for that use.

The Full Court agreed with the primary judge that mere suitability of a medicament for a claimed purpose cannot be determinative of the question of infringement of a Swiss-style claim.  The fact that the patent has been granted on the basis of a second medical use means that there are multiple uses to which the medicament could be put.  Evidence of suitability for use was therefore considered ambiguous and could not alone answer the question whether the medicament, as manufactured, is one for the specified therapeutic purpose.

Ultimately, the Full Court found that the Swiss-style claims, if valid, would not have been infringed by the manufacture of Sun’s competing product.  Of particular relevance to the Full Court’s decision was the fact that the competing product could be used in a large number of diseases other than retinopathy.

The decision validates the importance of including both Swiss-style claims and method of treatment claims when protecting a therapeutic use in Australia.  Both types of claim are permitted in Australia, and although their scope is limited to the specified therapeutic use, each will directly capture a different infringer.  In particular, Swiss-style claims provide a more direct avenue than method of treatment claims for pursuing manufacturers of competitive pharmaceutical products, rather than the medical practitioners who perform the treatment.

Consistory clauses may not provide fair basis if too broad 

Mylan’s third patent, relating to an immediate-release micronized formulation of fenofibrate, was found by both the primary judge and the Full Court to be invalid for lack of fair basis.  The Full Court endorsed the primary judge’s reasoning that the disclosure elsewhere in Mylan’s patent specification made clear that the invention was to the immediate release fenofibrate composition and a method for preparing it, whereas Mylan had advanced a construction of a consistory clause and corresponding claims to the effect that the invention extended to any composition of fenofibrate which satisfies the specified dissolution profile.  The Full Court affirmed that, as Sun Pharma had submitted, this is “a paradigm example of claims which travel beyond the matter disclosed in the specification”, amounting to invalidity for lack of fair basis.

The fair basis test considered in this case still applies to Australian patents for which examination was requested prior to 15 April 2013, when the “Raising the Bar” amendments came into effect.  The ‘fair basis’ requirement is generally considered to be a lower standard for patentees than the ‘support’ requirement that replaced it from 15 April 2013, which Australian Parliament expressly intended to align more closely with requirements under European law.  Therefore, if a consistory clause alone will not necessarily provide fair basis, that risk is likely to be even more significant for more recent patents and pending future patent applications required to meet the higher standard of support (such as an “enabling disclosure”).