In the recent Board of Appeal decision T 0070/23, GSK argued that its “immunogenic composition” product claim should be interpreted as limited by its efficacy as a vaccine, particularly in view of a description definition of the term. However, the Board of Appeal found both that product claims should not be interpreted as comprising therapeutic effects and that the description definitions do not override clear claim language. Whilst decided before G1/24, the decision is entirely aligned with recent interpretations of G1/24 by Boards of Appeal (Evolve Insights).
Legal background: Claim construction
The assessment of inventive step under Article 56 EPC is highly dependent on the objective technical problem, which is itself derived from the technical effect of the features distinguishing the invention from the closest prior art. It is therefore no surprise that patentees, when faced with a sticky inventive step objection, may argue for a claim construction that imports a technical effect from the description, such as therapeutic efficacy.
However, the case law of the Boards of Appeal has long warned against using the description to read limitations into a claim that has a clear technical meaning, especially with respect to product claims. As confirmed by the recent interpretations of the landmark EBA decision G1/24 on claim interpretation, the description cannot be used to give a different meaning to features in a claim, which themselves impart a clear, credible technical teaching to the skilled reader (Evolve Insights). Additionally, if a therapeutic effect is intended to be a limiting feature of the claim, the established approach is to use the purpose-limited product claim format under Article 54(5) EPC (although notably, this is the completely opposite to the UK approach to claim construction of medical use claims (Evolve Insights)).
Case background
The case in T 0070/23 related to EP 2903638 (GSK). The patent concerned immunogenic compositions derived from the capsular saccharides of Streptococcus agalactiae, also known as ‘group B streptococcus’, or ‘GBS’. The patent was opposed by Pfizer. Claim 1 of the main request was directed to “an immunogenic composition” comprising a cocktail of five different capsular saccharides from different GBS serotypes (Ia, Ib, II, III, and V) conjugated to a carrier protein. The claim specified “an immunogenic composition” but there was no dispute that the claim was a product claim, not a second medical use claim (r. 3).
Claim versus description
The main issue on appeal was inventive step, with the entire case hinging on the construction of the term “immunogenic composition”. GSK argued that the term “immunogenic” was a functional feature. GSK additionally submitted that, when read in conjunction with the description, the term implied efficacy as a vaccine.
The description included the following boilerplate paragraph:
“Immunogenic compositions used as vaccines comprise an immunologically effective amount of antigen(s), as well as any other components, as needed. By ‘immunologically effective amount’, it is meant that the administration of that amount to an individual, either in a single dose or as part of a series, is effective for treatment or prevention. Commonly, the desired result is the production of an antigen (e.g., pathogen)-specific immune response that is capable of or contributes to protecting the subject against the pathogen. This amount varies depending upon the health and physical condition of the individual to be treated, age, the taxonomic group of individual to be treated (e.g. non-human primate, primate, etc.), the capacity of the individual’s immune system to synthesise antibodies, the degree of protection desired, the formulation of the vaccine, the treating doctor’s assessment of the medical situation, and other relevant factors. It is expected that the amount will fall in a relatively broad range that can be determined through routine trials.“
According to GSK, the only technically sensible way of reading the claim in view of this description definition was to regard each constituent of the composition as having a protective/prophylactic effect.
Pfizer, on the other hand, submitted that given the claimed subject-matter was a product per se, it should not be defined or limited by its therapeutic efficacy. Pfizer further argued that it was established case law that the description should not be taken into account when construing claims that are clear on their own.
The Board of Appeal agreed with Pfizer. Citing T 932/99 and T 1018/02, the Board of Appeal found that the claim was not drafted as a purpose-limited product claim under Article 54(5) EPC, meaning that a therapeutic purpose or effect was not a feature of the claim. Additionally, for the Board of Appeal, the claim should further not be read as including the functional features set out in the description. The Board of Appeal further noted that, even if the description was considered, the cited paragraph only provided a general explanation of immunogenic compositions used as vaccines and not a definition of all compositions falling within the scope of the claim (presumably therefore, GSK would also have had issues trying to use this paragraph as basis for a more defined functional definition of the composition’s effect).
The Board of Appeal therefore interpreted “immunogenic composition” as used in the claims as a composition suitable for raising an immune response to at least one of the immunogens contained in it, wherein the level of protection against a specific disease should not be considered a feature of the claim (r. 11).
An obvious alternative
In view of the Board of Appeal’s claim construction, the technical effect for inventive step analysis was formulated simply as a composition that remained immunogenic. The objective technical problem was considered to be the mere provision of a further alternative immunogenic composition. The question then became whether the skilled person, starting from the prior art, would have arrived at the claimed composition to solve this problem. The Board of Appeal found that they would have in view of a direct suggestion in the prior art document that clearly presented the skilled reader with two arbitrary alternatives. The claimed composition was therefore found to lack an inventive step, and the patent was revoked.
GSK tried to rescue the patent with an auxiliary request that defined the composition as “a vaccine”, however this was not admitted for being late filed. The Board of Appeal considered that this amendment would not have overcome the issue as, even with the new wording, “a protective immune response against all of GBS serotypes present in the vaccine” would still not be considered a feature of the claim.
Relevance to G1/24
This case was decided before the decision in G1/24 was issued (Evolve Insight). However, interestingly, given what it considered the established case law on functional description definitions, the Board of Appeal did not find that its decision depended on any nuances that might have arisen from G 1/24. Whilst G 1/24 found that the description must always be “consulted”, this is not being interpreted by Boards of Appeal as giving patentees a free pass to use the description to rewrite the claims (Evolve Insight).
The Board of Appeal in the present case, whilst deciding before the G 1/24 decision was issued, was thus entirely in line with how G1/24 has been interpreted. However, like the cases to apply G1/24, this case related to the relevance of a potentially narrowing definition in the description. We await to see how the Boards of Appeal will respond to use of potentially broadening description definitions, such as in the referring case to G1/24, oral proceedings for which are scheduled for the end of this year (EP3076804).
Analysis
The decision in T 0070/23 is a clear reminder of the fundamental principle of patent law, emphasised recently in G1/24, that the claims define the scope of protection. This decision is also reminiscent of T 1924/20, in which the Board of Appeal similarly refused to import functional features from the description into the claims (Evolve Insight). It is common for claimed inventions in the pharmaceutical field to include a functional definition in the preamble of the claim, e.g. “a therapeutic composition”. T 0070/23 implies that these types of limitations in a product claim may be considered fundamentally meaningless by the EPO, whilst also potentially leading to difficulties of enforcement. T 0070/23 is also another reminder of the general pointlessness of boilerplate language, at least in EPO proceedings. The advice remains: the best way to limit a claim is in the claims, not the description (Evolve Insight).
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Further Evolve Insights
- Construing the claims to include technical effects mentioned in the description (T 1924/20)
- UK divergence from the EPO on plausibility (Sandoz v BMS), Part 1: Is the “plausibility” test the same for both sufficiency and inventive step?
- Beware of boilerplate: Practical lessons for patent drafting from G1/24 (Claim interpretation)
- First interpretation of G 1/24 (the description must always be consulted) (T 1561/23)
- G 1/24 in the spotlight: Description definitions do not override clear claim language (T 1999/23)
