Merck and Pfizer pneumococcal conjugate vaccine settlement prolongs uncertainty regarding Australian product claims

Recently, Merck Sharp & Dohme (MSD) (known as Merck & Co., Inc. in the US and Canada) announced a settlement and licence agreement with Pfizer Inc. in relation to MSD’s pneumococcal conjugate vaccine (PCV) products, including VAXNEUVANCE^TM (Pneumococcal 15-valent Conjugate Vaccine).

In Australia, the Merck and Pfizer pneumococcal conjugate vaccine matter was considered by the Federal Court in Merck Sharp & Dohme Corporation v Wyeth LLC (No 3) [2020] FCA 1477  (the Merck decision). Relevantly, the Merck decision included findings in relation to the validity of claims using the term “comprises” that sent a collective shiver down the spines of Australian patent applicants and their attorneys responsible for patent prosecution.

The claims in question defined a multivalent immunogenic composition comprising polysaccharide-protein conjugates, wherein each of the conjugates comprises a capsular polysaccharide from 13 different serotypes.  The Court construed the term “comprises” in the inclusive sense, which meant that the claims were found to encompass compositions with polysaccharide-protein conjugates from the 13 serotypes, as defined in the claims, as well as other polysaccharide-protein conjugates.  This was a significant issue for MSD because their vaccine product, having polysaccharide-protein conjugates prepared from 15 different serotypes, was found to infringe the claims in question.  However, the Court also found that because the technical contribution of the specification related only to the 13 serotypes defined in the claims, it did not provide support for additional polysaccharide-protein conjugates covered by the full scope of the claims.  For this reason, the claims were found to be invalid (at [551] and [552]).

The concern for Australian patent applicants was articulated by Wyeth who stated in their submissions that finding the claims invalid for lack of support was “contrary to patent law, because every product claim using the words ‘comprising’ or ‘including’ is liable to be revoked for lack of support” (at [555]).  However, the Court rejected this view by asserting that, “Whether other claims are invalid will depend on the particular language they use, and the scope of the disclosure in the relevant specification” (at [555]).

It is hardly surprising that Australian applicants, take little comfort from the Court’s view.  Most product claims use the words, “comprising”, “comprises” or “including” and, therefore, according to the Federal Court, these claims cover products having the defined components as well as any other components, including components that are not described in the description of the specification.  This arguably supports Wyeth’s view that many granted Australian product claims could be invalidated for lack of support.

The Merck decision at first instance was appealed and heard by the Full Court of the Federal Court in May 2021.  As the appeal decision was pending when the settlement between MSD and Pfizer was announced, no Full Court decision will be issued.  This leaves many Australian applicants uncertain in relation to the strength of their product claims.  Importantly, from a practical perspective, it means that Australian patent attorneys should consider including claims directed to products that are limited to components described or enabled by the specification.

It is highly likely that this issue will be raised in future litigation and Pearce IP will keep you promptly advised of relevant outcomes.