The bar has been raised: Prevnar® vaccine case demonstrates the impact of Australian patent law reforms

Merck Sharp & Dohme Corporation v Wyeth LLC (No 3) [2020] FCA 1477

 

Summary

Australia’s Federal Court has delivered judgment in a dispute concerning patents covering improvements in vaccines against Streptococcus pneumoniae, a leading cause of serious infections, particularly in children.  The judgment provides the first detailed analysis by a Federal Court judge of the Raising the Bar reforms to Australian patent law concerning sufficiency and support.  The decision demonstrates the profound implications of those reforms for permissible claim breadth in Australian patents.

Key takeaways

  • Australian patent law concerning sufficiency of description and support for claims underwent significant changes in 2012 as a result of the Raising the Bar amendments to the Patents Act 1990 (Cth) (Patents Act).
  • Due to generous transitional provisions, the amended law is only now coming before Australia’s Federal Court for interpretation and application.
  • European and UK authorities provide guidance on how the amended provisions of Australia’s Patents Act are likely to be interpreted and applied. In some cases, the amendments will result in a reduction in permissible claim breadth for Australian patents.
  • As a result of the transitional arrangements, many Australian patent disputes between now and least 2033 are likely to involve both patents subject to the pre-Raising the Bar law and patents subject the post-Raising the Bar Amendments may be required to avoid the latter patents being held invalid under the new, more stringent standards of sufficiency and support.

On 14 October 2020, Justice Stephen Burley delivered the judgment of the Federal Court of Australia in Merck Sharp & Dohme Corporation v Wyeth LLC (No 3) [2020] FCA 1477.  The case concerned three patents owned by Wyeth LLC (Wyeth) relating to improvements in immunisation against infection by Streptococcus pneumoniae, a bacterium responsible for meningitis, pneumonia and other serious illnesses, especially in children.

Justice Burley’s decision provides the first detailed analysis by the Federal Court of Australia concerning amendments made in 2012 to Australian patent law on the topics of sufficiency of description and support for claims.  The decision highlights the significant implications of those amendments for patent validity and claim scope.

The technology

Streptococcus pneumoniae (also referred to as “pneumococcus”) has an outer capsule that incorporates complex sugars known as polysaccharides.  Differences in capsular polysaccharides distinguish variants of pneumococcus, called “serotypes”.  More than 90 distinct serotypes have been described.  A more limited group of virulent serotypes are responsible for most serious pneumococcal infections.

The antibody response to capsular polysaccharides is generally poor in young children.  As a result, they are particularly susceptible to pneumococcal infections, which globally account for around 1 to 2 million childhood deaths each year.

To address this problem, “polysaccharide-protein conjugate vaccines” were developed with the aim of stimulating immunity against serotypes of pneumococcus known to be responsible for a high proportion of human infections.  In such vaccines, capsular polysaccharides are joined (“conjugated”) to a carrier protein, leading to a stronger antibody response than is achievable with vaccines based on capsular polysaccharides alone.

A polysaccharide-protein conjugate vaccine against pneumococcus developed by Wyeth, known as Prevnar 7®, was in clinical use before the priority date of the Composition Patents.  That product is a “7-valent” vaccine.  It comprises capsular polysaccharides from 7 different pneumococcus serotypes, in each case conjugated to a single protein (known as “CRM197”).  Evidence led in the case indicated that, before the priority date, steps had been taken to develop 9-valent and 11-valent polysaccharide-protein conjugate vaccines against pneumococcus, but no such products had yet been licensed or launched.

The patents

Three patents were at issue in this proceeding.  Two of them, referred to by Burley J as the “Composition Patents”, were related members of the same patent family.  The more senior family member (referred to here as the “Parent Composition Patent”) was subject to the provisions of Australia’s Patents Act as they stood prior to the Raising the Bar amendments.  The more junior family member (referred to here as the “Child Composition Patent”) was subject to the post-Raising the Bar Patents Act.  The body of the specification was substantially the same in the parent and child patents.  It described multivalent immunogenic compositions (that is, vaccines) comprising 13 distinct polysaccharide-protein conjugates, thereby providing increased coverage of pneumococcal serotypes compared to the existing Prevnar 7® vaccine.

A third patent asserted by Wyeth in the proceeding, referred to by Burley J as the “Container Patent”, disclosed siliconized container means for the stabilization of polysaccharide conjugates.  The issues raised in the proceeding in relation to the Container Patent are not discussed here.

The proceedings

Merck Sharp & Dohme (MSD) sought revocation of Wyeth’s Composition Patents on a variety of grounds, including lack of novelty, lack of inventive step (i.e., obviousness), false suggestion, lack of clarity, lack of fair basis (in relation to the pre-Raising the Bar Parent patent) and lack of support (in relation to the post-Raising the Bar Child patent).

By a cross-claim, Wyeth alleged that a 15-valent pneumococcal vaccine which MSD proposed to launch and market in Australia would infringe selected claims of all three of the asserted patents.

Wyeth’s allegation that the Composition Patents would be infringed by marketing of MSD’s 15-valent vaccine in Australia gave rise to a critical issue of claim construction in the proceeding, namely, whether the claims of those patents were limited to 13-valent vaccines (as MSD contended) or extended to vaccines covering 13 or more serotypes (as Wyeth submitted).

The construction issue

Claim 1 of the Parent Composition Patent was in the following terms:

A multivalent immunogenic composition, comprising: 13 distinct polysaccharide-protein conjugates, together with a physiologically acceptable vehicle, wherein each of the conjugates comprises a capsular polysaccharide from a different serotype of Streptococcus pneumoniae conjugated to a carrier protein, and the capsular polysaccharides are prepared from serotypes 1, 3, 4, 5, 6A, 6B, 7F, 9V, 14, 18C, 19A, 19F and 23F and wherein said carrier protein is CRM197.

Insofar as is presently relevant, claim 1 of the Child Composition Patent was in similar (although not identical) terms.

The specification of each of the Composition Patents included text (standard in Australian patents) indicating that “comprising” is used in an inclusive sense (“including”) rather than an exhaustive sense (“consisting of”).  That text provided the basis for Wyeth’s submission that, because MSD’s 15-valent vaccine included the 13 serotypes identified in the claims of the Composition Patents, it fell within those claims.  On Wyeth’s construction, the presence of two additional serotypes in MSD’s 15-valent vaccine was irrelevant to infringement.

Arguing to the contrary, MSD submitted that its construction (limiting the claims to 13-valent vaccines) was the only construction consistent with the description of Wyeth’s invention in the specification taken as a whole.  A corresponding submission, based on similar (but not identical) claim language, had been accepted in related UK proceedings between MSD and Wyeth (see Merck Sharp & Dohme Limited v Wyeth LLC [2020] EWHC 2636 (Pat) at [251]-[270]).

However, on this key issue, Burley J preferred Wyeth’s construction.  In his Honour’s analysis, the inclusive definition of “comprising” was decisive.  Provided that a vaccine included each integer of Wyeth’s claims (including, relevantly, the 13 specified serotypes), it would infringe – a conclusion not altered by the presence in the infringing product of additional serotypes.

What is notable for present purposes is the very substantial breadth given to Wyeth’s claims on the construction adopted by Burley J.  On that construction, the range of valences covered by Wyeth’s claim would appear to have no upper bound.

Unsurprisingly, in view of this broad construction, a question arose as to whether the claims were fairly based on, or supported by, the disclosure contained in the body of the Composition Patent specification.  On that legal issue, the Raising the Bar amendments have brought about a profound shift in Australian law, as Burley J’s judgment demonstrates.

Raising the Bar reforms

The Raising the Bar reforms were introduced to address concerns that Australia’s patent standards were lower than those of its major trading partners, causing Australia’s innovation landscape to become cluttered with unduly broad patents.  The amendments were expressly directed at aligning key aspects of Australian patent law, including on sufficiency of disclosure and support for claims, with the standards applied by UK courts and the European Patent Office (EPO) Boards of Appeal.

Although the Raising the Bar amendments were enacted in April 2012, lengthy transitional provisions mean that many of the key reforms, including those concerning sufficiency and support, are only now coming before the courts for interpretation and application.

The law pre-Raising the Bar

Prior to the Raising the Bar reforms, the relationship between the disclosure in the body of a patent specification and the breadth of the claims was governed by the legal requirement for “fair basis”.  The leading authority on that requirement (Lockwood Security Products Pty Ltd v Doric Products Pty Ltd (2004) 217 CLR 274) established that fair basis does not turn on any inquiry into the patentee’s “technical contribution to the art”, but rather on whether each claim corresponds textually with what the patentee has described as their invention in the body of the patent specification.

The practical effect of Lockwood’s permissive interpretation of the fair basis requirement was amplified by the equally permissive interpretation of the sufficiency requirement given in the leading authority pre-Raising the Bar (Kimberly-Clark Australia Pty Ltd v Arico Trading International Pty Ltd (2001) 207 CLR 1).  That case stands as authority for the proposition that a patent specification will have adequately described the invention if it would enable a person skilled in the relevant art to produce “something” falling within each claim (referred to colloquially as the “one way rule”).

That body of law is of continuing relevance for Australian standard and innovation patents for which examination was requested before 15 April 2013.  In the present case, that “old” body of law applied to the Parent Composition Patent.

Applying those authorities, Burley J found little difficulty in concluding that, notwithstanding his Honour’s broad interpretation of the claims of the Parent Composition Patent, those claims were fairly based.  Reflecting the essentially textual nature of the pre-Raising the Bar test for fair basis, that conclusion followed from the fact that the description of the invention in the body of the Parent Composition Patent employed the same inclusive language (“comprising”) as appeared in the claims.

The law post-Raising the Bar

Following the Raising the Bar amendments, the provisions of Australia’s Patents Act dealing with sufficiency and support are in substantially the same terms as the corresponding provisions of the European Patent Convention and the United Kingdom’s Patents Act 1977.  Parliamentary records make clear that those provisions were intended to have substantially the same effect as their European and UK counterparts, and that Australia courts are expected to have regard to decisions of the EPO Boards of Appeal and of UK courts in interpreting those provisions.

Burley J reviewed a number of EPO and UK authorities, including the recent decision of the UK Supreme Court in Regeneron Pharmaceuticals Inc v Kymab Ltd [2020] UKSC 27, to interpret the post-Raising the Bar requirement that the claims be “supported by matter disclosed in the specification”.

Referring to the landmark decision of the House of Lords in Biogen Inc v Medeva Plc [1997] RPC 1, Burley J observed that the claim support obligation has come to be understood as falling “under the umbrella of the requirement that the patent specification contain an enabling disclosure”.  His Honour noted that, although the requirement for sufficient description is directed to the specification as a whole, while the requirement for support is directed specifically to the claims, both requirements serve to ensure that a person skilled in the relevant art, armed with the patentee’s specification, is enabled to perform the invention over the whole area claimed without undue burden.

Referring to the decision of the EPO Board of Appeal in Exxon/Fuel Oils (T 409/91) [1994] EPOR 149, Burley J noted that the requirement for enablement across the full claim scope has been recognised as reflecting the general legal principle that the scope of a patent monopoly, as defined by the claims, should correspond to the patentee’s technical contribution to the art, as disclosed in their specification.

Applying those authorities, Burley J concluded that the claims of the Child Composition Patent were not supported by the matter disclosed in the specification.  On the construction advanced by Wyeth and accepted by His Honour, those claims encompassed any polysaccharide-protein conjugate pneumococcal vaccine comprising 13 or more serotypes (provided the other claim integers were satisfied).  While there was no dispute that the specification of the Composition Patents would enable a skilled person to make and use a 13-valent vaccine, uncontested evidence established that the disclosure of the specification could not be extrapolated to vaccines containing other, additional serotypes.  Manufacture of polysaccharide-protein conjugate vaccines comprising more than 13 serotypes was not enabled.

In the result, the asserted claims of the Parent Composition Patent were held to be valid and infringed, while the asserted claims of the Child Composition Patent were held invalid for lack of support.

Significance of the judgment

The disparate conclusions reached in this case concerning the Parent and Child Composition Patents serve to illustrate the profound changes to Australian law brought about by the Raising the Bar reforms.

Observers in other jurisdictions may find it curious that such starkly different findings could be made on the basis of very closely similar patent specifications.  The principle upon which the Child Composition Patent was held invalid (i.e., the requirement that claim breadth correspond to the patentee’s technical contribution to the art) is said to reflect the “essential patent bargain” whereby the patent holder is granted a time-limited monopoly in return for disclosing their invention in terms sufficiently clear and complete for it to be performed by those skilled in the art.  The fact that this requirement did not apply to the Parent Composition Patent serves to illustrate the extent to which, in the pre-Raising the Bar era, Australian patent law had diverged from the law applied by its major trading partners.

Such disparate outcomes are likely to remain a feature of Australian patent disputes for some years to come.  Australian patents subject to the pre-Raising the Bar law are expected to remain in force until at least 2033.

This decision also demonstrates that the post-Raising the Bar incarnations of Australia’s written disclosure requirements in s 40 of the Patents Act 1990 (Cth) can be a much more powerful weapon in the arsenal of a party seeking to revoke an Australian patent.  Historically, the low thresholds for fair basis and sufficiency have provided relatively wide scope for Australian patentees in advancing positions on claim construction to capture alleged infringements.  This main constraint for patentees in advancing claim construction under the pre-Raising the Bar body of law has been (and will remain) potential novelty and inventive step consequences arising from constructions being so broad as to capture prior art or common general knowledge.  The onerous post-Raising the Bar support and sufficiency requirements will add an extra dimension to these construction “squeezes” and another powerful validity ground which must be fended off.

Furthermore, notwithstanding parliament’s intention that the post-Raising the Bar provisions concerning sufficiency of description and claim support be interpreted so as to have substantially the same effect as the corresponding provisions of European and UK law, lingering disparities between the law of those jurisdictions and the terms of Australia’s Patents Act mean that some independent development of Australian law on sufficiency and support appears inevitable.  Two examples may be noted.

First, under the UK’s Patents Act 1977, although both sufficiency and support are requirements for a valid patent application, only lack of sufficiency is available as a ground of revocation for granted patents.  UK courts have remedied that “logical gap” by recognising both requirements as aspects of a single unifying requirement for an enabling disclosure.  No such logical gap exists in Australia’s Patents Act, where both lack of sufficiency and lack of support are available as grounds for revocation.  Whether this difference will lead Australian courts to seek to disentangle the threads of sufficiency and support in the UK authorities remains to be seen.

Secondly, by contrast to the requirements of European and UK law, Australia’s post-Raising the Bar Patents Act continues to impose a requirement to disclose the “best method”.  European and UK authorities provide no guidance on how that requirement is to be accommodated with the law regarding sufficiency and support.  For such guidance, it may be necessary for Australian courts to look to United States authorities.  Whether they will choose to do so remains to be seen.

Given the significant commercial interests at stake, and the complexity of the legal and factual issues raised by the Prevnar® case, the likelihood of an appeal appears reasonably high.  Whether any appeal judgment casts further light on Australian patent law post-Raising the Bar is likely to depend upon whether the appeal court upholds the broad construction of Wyeth’s Composition Patent claims that was accepted by Burley J.