In a recent decision of the Federal Court of Australia[1], Wyeth’s vaccine composition patent was found invalid for lack of support where the use of “comprising” language resulted in the claims encompassing vaccines having additional polypeptide-protein conjugates beyond the 13 specified in the claims.

Together with other recent decisions, the MSD v Wyeth judgment demonstrates the more exacting standard now required for the level of disclosure in patent specifications. It also cements the shift in Australia towards alignment with UK and European requirements.

Wyeth v MSD 

The judgment in MSD v Wyeth concerned three Wyeth patents[2], two directed to vaccine compositions containing polysaccharide-protein conjugates, and the third protecting a siliconized container for stabilising such compositions. The patents protected Wyeth’s Prevnar 13® vaccine which prevents pneumonia. MSD had sought to launch its own 15-valent pneumococcal conjugate vaccine. Whilst one of the composition patents was held valid and infringed, the other two patents were found to be invalid.

At the heart of the case was the question of whether a claim to:

“A multigenic immunogenic composition, comprising polysaccharide-protein conjugates…wherein each of the conjugates comprises a capsular polysaccharide…prepared from serotypes 1,3, 4, 5, 6A, 6B, 7F, 9V, 14, 18C, 19A, 19F and 23F…”

in Australian patent no. 2013206844 was infringed by MSD’s 15-valent vaccine which contained not only the 13 capsular polysaccharides specified in the claims but also 2 others and, if so, whether the claim was consequently invalid for lack of support.

Given that an inclusive construction is typically given to the term “comprising”, it is not surprising that Burley J decided the former point in favour of the patentee and held that MSD’s vaccine infringed the claim. MSD had argued that the claim language should be limited to a composition having only the 13 serotypes specified and excluding other serotypes, on the basis that their construction was consistent with the description of the invention in the specification. The judge rejected that position, referring to definitions in the specification which defined “comprising” inclusively, and highlighting inconsistencies resulting from MSD’s interpretation, since there was a dependent claim which specified additional components of the composition.

However, when it came to assessing whether the claims were supported, the breadth of the claims became problematic for the patentee. The judge held that the technical contribution to the art lay in the identification of specific additional serotypes over those present in the prior art, by means of which a 13-valent composition could be made, but that the disclosure of the specification was not for a principle of general application going beyond that 13-valent product. There was also evidence that the selection of additional serotypes would be a complex and difficult process. Although that assisted Wyeth’s inventive step position, it created difficulties for the patentee in arguing that claims covering MSD’s 15-valent vaccine were supported, and the claims were found to be invalid.

Notably, the grandparent patent 2006235013 was upheld when assessed under the previous (more lenient) support provisions of “fair basis” – despite having similar claims.

Towards a UK/European standard for specification disclosure requirements 

The MSD v Wyeth decision is one of several highlighting a shift with respect to the level of disclosure required in patent specifications, towards UK and European requirements. This aligns with the intent behind the Raising the Bar legislative changes in 2013[3].

In reaching his decision on the support issue, Burley J referred to UK jurisprudence concerning “Biogen insufficiency”[4]. Lack of support is not a ground of revocation in the UK, however the judge drew from the position of the UK House of Lords that the claim support obligation falls under the umbrella of the requirement that a patent specification must contain an enabling disclosure. Burley J set out that, for a claim to be supported or justified across its breadth, it must correspond to the technical contribution to the art. Reference was also made to principles summarised in the recent decision of the UK Supreme Court in Regeneron v Kymab[5]: that the technical contribution to the art is not necessarily the same as inventive step, rather for a claim to a product or group of products it is the products themselves; and that the disclosure in the specification should be sufficient to make substantially all embodiments, except for de minimis exceptions.

Prior to the judgment in MSD v Wyeth, there had been several Australian patent office decisions which addressed support and/or sufficiency requirements under the post-Raising the Bar regime.

In the first decision to consider support and sufficiency post-Raising the Bar, CSR Building Products Ltd v United States Gypsum Company[6], a patent application having claims to fire resistant gypsum panels required to achieve certain properties was found to be invalid. In that case, drawing from a UK decision Schering Biotech Corp’s Application[7], the Delegate in CSR referred to a general approach for assessing support based on ascertaining the invention specified in the claims and comparing that with the invention specified in the description, with “the description having to be a base which can fairly entitle the patentee to a monopoly of the width claimed”. In MSD v Wyeth, Burley J agreed with the general approach adopted in CSR but emphasised in addition the need to ascertain the technical contribution to the art, as discussed above.

The CSR decision also considered sufficiency of disclosure and proposed the relevant question as being whether a person seeking to follow the instructions in the specification could adjust the process and materials so as to achieve with certitude the full combination of properties claimed. However, more recent Australian patent office decisions that considered sufficiency have introduced a plausibility test, like the approach taken by UK courts. For example, in the Evolva[8] and Gary B Cox v MacroGenics, Inc.[9]decisions, the Delegate set out a test for determining whether the specification provides an enabling disclosure of everything falling within the claims based on whether:

a) Is it plausible that the invention can be worked across the full scope of the claim; and

b) Can the invention be performed across the full scope of the claim without undue burden.

The move in Australian practice towards the UK and European position is also evident from the CSIRO v BASF decision earlier in 2020.[10] That case concerned the question of whether an amendment introduced added matter contravening s102(1) of the Patents Act 1990, rather than whether the claims were supported, but again emphasised the need for an Australian patent specification to contain a detailed disclosure of the invention. The amendment at issue involved the specification of one feature of an enzyme (conversion preference) in the claims without specifying another (substrate specificity), when the two features were only disclosed in combination in the original specification. The amendment was found to be an impermissible intermediate generalisation based on the original disclosure, and reference was also made to the “clear and unambiguous disclosure” test referred to by the UK courts in Bonzel v Intervention[11].

"Comprising" claims in Australia

In MSD v Wyeth,Wyeth raised concerns about the impact of a finding of lack of support in that case, on the validity of other Australian patents also having “comprising” product claims. However, Burley J dismissed the proposition that finding the present claims invalid would automatically result in all product claims using the words “comprising” lacking support. Rather, it was emphasised that validity of other claims would depend on the particular claim language used and the scope of the disclosure in the specification.

As discussed above, in this case there was evidence supporting that the selection of additional serotypes beyond the 13 specified in the claims would be a complex and difficult process. Accordingly, patents containing “comprising” claims may be more vulnerable in situations where there is a gap between the disclosure in the specification and the breadth of the claims, which cannot be not filled by the common general knowledge or the routine capabilities of the skilled addressee.

It seems likely that with respect of MSD v Wyeth, if exclusive “consisting of” terminology had been used to define the capsular polysaccharide-protein conjugate component of the composition, the claim may have survived. However, such a claim would have been of considerably less value to the patentee, encompassing Wyeth’s product but not the Merck 15-valent vaccine.

Final Comments 

The judgment in MSD v Wyeth, together with other recent decisions of the Australian authorities, highlight that the shift towards UK and European practice in respect of disclosure requirements for Australian patent specifications is purposeful.

Impact on patent drafting practice in Australia is likely to be minimal, since most Australian-originating specifications are already drafted to meet requirements of major patent offices including the USPTO and the EPO. During invalidity proceedings to Australian patent applications, we may however expect to see increased references by parties to invalidity attacks raised in respect of corresponding UK and European patents.