In high value chemical areas where competition is rife, establishing a strong priority claim and carefully crafting the subsequent priority claiming application can be crucial to protecting a commercial chemical product.
We (Jessica Smart, Andrea Coles and Kathryn Bradley) recently held a webinar with practical tips on how to draft a patent application to allow the best chance of a European patent being granted with broad coverage which is robust enough to enforce and survive EPO opposition and appeal challenges, as well as national and UPC litigation.
Key takeaways & practical tips
We highlighted the following key takeaways.
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Ensure that both the priority application as well as the subsequent priority claiming application are drafted with European requirements in mind. This will help ensure a strong priority claim and strengthen the Applicant’s position against intervening prior art.
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Amendments made during prosecution must be ‘directly and unambiguously derivable’ from the application as originally filed to satisfy the EPO’s strict added matter requirements. There are many potential pitfalls when it comes to added matter in Europe and a particularly important point when drafting is to include layering in the application to provide useful fall-back positions between the broadest and narrowest embodiments, drafted such that they can be used in combination without adding matter.
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To improve the chance of successfully arguing for inventive step in Europe, it is advisable to include as much data as possible in the application demonstrating an advantage. Having data showing a technical advantage in the application as filed can be extremely valuable during European prosecution because it can be used to establish the objective technical problem as an improvement rather than an alternative over the prior art. In particular, direct comparative data showing the benefit over relevant prior art can be very useful.
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If you expect that you may need to rely on post-filed data to demonstrate an effect, it is important to ensure that the effect is at least derivable from the originally filed application. The EPO’s Enlarged Board of Appeal noted in G 2/21 that the effect should be “encompassed by the technical teaching and embodied by the same originally disclosed invention” (more detail here).
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Parameters, i.e. measurable physical or chemical properties that are used to define an invention where using structural features would not be possible or would be too limiting, are common in high value chemical patent applications. Examples include particle size and viscosity. The EPO requires that a claim with a parameter must include a method of measuring the parameter, otherwise it may be objected to as lacking clarity. When drafting patent applications with a parameter, include a clearly defined method of measurement (such as an ASTM standard), drafted such that it can be introduced into the relevant claim. Due to the strict approach adopted by the EPO in their assessment of added subject-matter, it is often difficult to remove an offending parameter from a claim without causing further issues post-grant – see here for more detail on the ‘unclear essential parameter trap’.
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Ranges are a very common feature in chemical patents. In Europe, the disclosure of a range of values together with an included preferred narrower range also directly discloses the two possible part-ranges lying within the overall range on either side of the preferred narrower range. In the example shown below, starting from disclosures in the application as filed of ‘5 to 60’ and ’15 to 45’, the Applicant could create a new range such as ‘15 to 60’ or even ‘45 to 60’. When drafting, provide different ranges, including preferred ranges to allow combinations of ranges.
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‘Relative terms’ are words that don't have fixed meanings, but instead depend on what they're being compared to, and include words like 'thin,' 'high,' 'wide,' and 'strong'. Specific definitions of such terms should be provided in the application as filed. If a relative term is used by the applicant as the only feature to distinguish the subject-matter of a claim from the prior art, the use of this term is usually objected to for lacking clarity. For example, a “high-temperature” reaction step may have a different meaning in different contexts, so including a specific numerical range and/or value is important.
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A further pitfall to avoid when drafting for Europe is a lack of clarity due to a claim relating to a ‘result to be achieved’. This means that the claim defines the invention by the desired outcome rather than the technical features that achieve that outcome. Generally, such a claim is not allowed at the EPO. In order to avoid this, include technical details that achieve the outcome in your application. For example, if your invention is an odour-absorbing substrate where a porous microstructure is responsible for this effect, your product claim should include details of this porous microstructure.
If you have any questions or if you would like to discuss any of the topics covered in the webinar in more detail, please feel free to reach out to our speakers, Jessica Smart, Andrea Coles and Kathryn Bradley.