When considering the boundaries of the monopoly associated with a patent, it is necessary to interpret the claims of the patent accurately to properly stake out the metes and bounds of the monopoly claimed.
In the recent decision in Pharmacia LLC v Juno Pharmaceuticals Pty Ltd  FCA 92, Burley, J found it necessary to consider certain terms within the claims of the corresponding patent in order to gain a proper understanding of the scope of the claims, and thus, the invention claimed.
The decision is of particular relevance as it relates to two of the most common terms used in patent claims.
By way of background, Pharmacia LLC ("Pharmacia") initiated proceedings against Juno Pharmaceuticals Pty Ltd ("Juno") in August 2019, with allegations that Juno were marketing products in Australia that infringe the claims of Australian Patent No. 2002256031 (the "Patent"), entitled: "Reconstitutable parenteral composition containing a COX-2 inhibitor". Juno denied infringement and cross-claimed, challenging the validity of certain claims of the patent.
Before being able to provide a decision on infringement and validity, his Honour, Burley J, was first required to consider the question of claim construction.
The rules of claim construction are conveniently listed here, and can be summarised as follows:
- A patent specification should be given a purposive construction rather than a purely literal one;
- The words used in a patent specification are to be given the meaning which the normal person skilled in the art would attach to them, having regard to his or her own general knowledge and to what is disclosed in the body of the specification; and
- While the claims are to be construed in the context of the specification as a whole, it is not legitimate to narrow or expand the boundaries of monopoly as fixed by the words of a claim by adding to those words glosses drawn from other parts of the specification, although terms in the claim which are unclear may be defined by reference to the body of the specification.
In other words, the primary requirement is for the patent specification to be read as a whole, in light of the common general knowledge in the art of a notional, non-inventive person skilled in the art, before the priority date of the patent.
With the above mind, Burley J turned to the patent specification, and to the opinions of the expert witnesses representing each party, for guidance with respect to understanding the meaning of the term "about", as recited in Claims 1 and 26, and the term "essentially", as recited in Claim 11.
The term "about" is a relative term, and in the context of the claims of the patent in suit, it is used to define the weight ranges of the various components of the pharmaceutical composition claimed.
For instance, claim 1 of the patent recites, in pertinent part:
"A pharmaceutical composition comprising: ". (a) at least one water-soluble therapeutic agent.in a therapeutically effective total amount constituting about 30% to about 90% by weight."
During the proceedings, Pharmacia submitted that the term "about" should be understood to allow for a 5% margin of error, so that "about 90%" in claim 1 would extend to 94.5% as its upper limit (5% of 90% being 4.5%), as supported by specific examples and disclosures in the specification.
In contrast, Juno contended in their submissions that "about" merely allows for rounding to the nearest whole number, such that "about 90%" would extend to 90.49% as its upper limit.
Burley J observed that there was no definition for "about" in the specification. As such, he was obliged to consider the evidence proffered by the expert witnesses.
In this respect, it was agreed by the formulation experts for the two parties that "about" is an imprecise term and is "mostly avoided in the natural sciences" on account of it being difficult to define from a scientific perspective.
In support of Pharmacia's position, the formulation expert for this party attempted to argue that the specification provides rationale for the broader percentage range on account of certain passages related to, for example, the percentage of residual water contained in the pharmaceutical composition being less than about 5%. However, the same passage also provided that "typically the moisture content is about 0.5% to about 1% by weight".
Burley J took this last statement as an indication that a skilled person in the art would look to the "typical" percentage range when determining the residual water content in the pharmaceutical composition rather than a percentage of less than about 5%.
Burley J was not convinced that the passages relied upon by Pharmacia provided the necessary support for the use of a 5% margin of error. Hence, in the absence of expert guidance, Burley J turned to the ordinary English meaning of the term ("near; close to"), as defined in the Macquarie Dictionary (5th edn).
Given this definition, and how it relates to the use of the term "about" in the specification, Burley J erred on the side of Juno in applying a relatively narrow construction of the term "about" 'in relation to the weight percentage ranges of the components in the composition, allowing for rounding to the nearest whole percentage, rather than allowing for a 5% margin of error.
The term "essentially", like "about" is a relative term, and in the context of the claims of the patent in suit, it is used to define the major constituents of the pharmaceutical composition claimed.
For instance, claim 11 of the patent recites, in pertinent part, that:
"The composition.consists essentially of the therapeutic agent and the buffering agent."
Again, Burley J observed that there was no definition for "essentially" in the specification. As such, he was obliged to consider the evidence proffered by the expert witnesses.
Here, the formulation experts for the two parties agreed that in the context of claim 11 "essentially" means "mostly" such that the composition of the claim contains "mostly, but not exclusively", the therapeutic agent and a buffering agent, but other things (such as water) could also be present.
Burley J found that equating "essentially" with "mostly" accords with the description of the invention, which, after stating that the buffering agent is present in an amount of about 5% to about 60% and is typically the predominant excipient ingredient, provides that in one embodiment "the reconstitutable powder composition consists essentially of the therapeutic agent and the buffering agent".
Burley J indicated that the word "essentially", like "mostly", is a relative term that by itself is of no definite meaning. However, taken in the context of the specification as a whole, it is apparent that the description of the embodiment as consisting "essentially" of the therapeutic agent and buffering agent does no more than identify a composition that contains something within the upper range of the percentages of therapeutic agent and buffering agent that are specified in claim 1.
Burley J then went on to indicate that given that claim 11 is dependent on claim 1, it is to be read such that the invention claimed in claim 11 is a subset of the composition of claim 1 (it is "the composition of any of claims 1 to 6"). Claim 1 prescribes that the total amount of excipient ingredients is to amount to no more than about 10% by weight of the composition. Accordingly, compositions of claim 11 must have at least about 90% by weight of therapeutic agent and buffer. This accords with the ordinary meaning that the composition consists "essentially" (or mostly) of therapeutic agent and buffer.
To summarise, Burley J resolved the construction issues as follows:
- The word "about", insofar as it refers to relative weight percentages in the relevant claims, means rounding up or down to the nearest whole number percentage; and
- The use of the word "essentially" in claim 11 does not extend the scope of the monopoly claimed beyond the limits of claim 1.
From this decision, it is apparent that if the words used in a claim are intended to have a particular meaning which might differ from their plain everyday meaning or are intended to import a functional requirement associated with how the invention works in practice, then it is crucial that such a meaning or function is adequately described in the specification.
If such a description is not available, then patentees run the risk of having a plain reading of the claim forced upon them.
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