23 October 2026
Patent disputes can involve extraordinarily complex technology.
Even so, sometimes the outcome turns on the meaning of a handful of words.
A recent Federal Court decision involving Pfizer and Samsung Bioepis is a useful example of just how important patent claim drafting and claim construction can be.
The case concerned technology used in the production of therapeutic proteins and a Pfizer patent relating to large-scale cell culture processes.
One of the key questions was what the patent meant by a “medium containing glutamine”.
What did “medium” actually mean?
Pfizer argued for a broader interpretation that could take account of glutamine coming from a number of sources within the production process.
The respondents argued for a narrower interpretation.
The Court concluded that “medium” referred to the formulated batch and feed media. It did not extend to glutamine coming from the inoculum, cell secretions or contaminants in the production bioreactor.
That interpretation had an immediate impact on the infringement case.
One of Samsung Bioepis' manufacturing processes contained glutamine in the relevant medium, while another did not.
On the Court's construction, the second process did not satisfy that part of the patent claim.
There were other infringement issues in the case as well, including whether a separate requirement concerning viable cell density had been established. Pfizer ultimately failed to establish infringement.
Drafting for the invention, and for the alternatives
The case illustrates a broader patent drafting challenge.
A patent specification needs to describe the invention sufficiently and define the monopoly with precision. However, the wording of the claims also needs to anticipate how competitors may develop alternative ways of achieving a similar commercial result.
A competitor does not necessarily infringe a patent simply because its technology achieves the same outcome. The question is whether what it does falls within the properly construed patent claims. Therefore, that makes the words chosen during drafting extremely important.
The other side of the equation: validity
Patent claims cannot simply be drafted as broadly as possible.
The broader the monopoly being claimed, the greater the possibility that prior art may become relevant and that issue was also prominent in the Pfizer case.
The respondents challenged the patent on a number of grounds, including lack of inventive step.
The Court found that all but one of the asserted claims lacked inventive step in light of the common general knowledge and a piece of prior art. Only Claim 2 survived.
Ultimately, Pfizer's infringement case failed and all but one of its asserted claims were found invalid for lack of inventive step.
Patent drafting is a balancing exercise
This is the difficult part of patent strategy.
On the one hand, claims need to be broad enough to provide commercially meaningful protection and capture foreseeable alternatives. Yet they also need to remain defensible against the prior art and the other requirements for patent validity.
That balance needs to be considered from the beginning.
Once a competitor has adopted an alternative process and litigation has started, the wording of the patent is largely already fixed.
IP Solved works with businesses and inventors to develop patent strategies that consider not only the invention being developed today, but also its commercial value, possible alternatives and the scope of protection that may be needed in the future.
