Amending a functional therapeutic claim without added matter
Swiss pharmaceutical company VaudRx files EP application EP 24 xxx on 8 February 2024, claiming priority from Swiss application CH 00112/23 filed 6 February 2023. Claim 1 reads: 'A method of treating migraine in a human comprising administering compound X at a dose of 5 mg/kg, wherein the dose is optimized in real time based on a biomarker.' The priority application discloses compound X, migraine treatment, and a dose of 5 mg/kg, but says only that the dose 'may be adjusted in response to biomarker levels'. The words 'optimized' and 'real time' do not appear. The examples show adjustment between 3 and 7 mg/kg based on biomarker Z. The EPO issues a communication raising added matter under Art. 123(2) EPC and clarity/support under Art. 84 EPC, and notes that the claim is directed to a method of treatment. VaudRx wants to keep the 5 mg/kg dosage and the biomarker-based adjustment in the claim.
1. How should claim 1 be amended to overcome the added-matter objection while preserving priority?
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The objection is well founded. 'Optimized in real time' is a functional characterization that is not disclosed in the priority application. 'Adjusted in response to biomarker levels' is disclosed; 'optimized' implies a selection of the best dose, and 'real time' implies immediate measurement and feedback, neither of which is literally or implicitly present. Under Art. 123(2) EPC, the amendment must be directly and unambiguously derivable from the original disclosure.
A defensible amendment is: 'A method of treating migraine in a human comprising administering compound X at a dose of 5 mg/kg, wherein the dose is adjusted within the range of 3 to 7 mg/kg in response to a measured level of biomarker Z.' This uses the disclosed range and biomarker, removes 'optimized' and 'real time', and keeps the 5 mg/kg dose. If the priority application discloses the 3 to 7 mg/kg range and biomarker Z, the amended feature has priority. If those features appear only in the EP application and not in the priority application, priority is lost for the amended subject-matter, and the applicant must check for intervening prior art.
The applicant should not simply replace 'optimized' with 'adjusted' while leaving 'real time' in the claim. 'Real time' remains unsupported and would invite a second added-matter objection. The amendment should be accompanied by a basis statement citing the priority application page and line for each feature.
2. Is the claim allowable as a method of treatment at the EPO, and how should the claim category be changed?
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No. Under Art. 53(c) EPC, methods for treatment of the human or animal body by surgery or therapy and diagnostic methods practised on the human or animal body are not patentable. A claim beginning 'A method of treating migraine in a human comprising administering...' is a therapeutic method and falls within the exclusion, even if the active agent and dosage are novel.
The applicant should switch to a purpose-limited product claim or a Swiss-type claim. For EPC practice, 'Compound X for use in the treatment of migraine, wherein...' is allowable, and the dosage and biomarker adjustment can be limiting features if they are disclosed and supported. Alternatively, 'Use of compound X in the manufacture of a medicament for the treatment of migraine, wherein...' is a Swiss-type claim. The latter is useful for jurisdictions that do not allow method-of-treatment claims.
The choice affects infringement and evidence. A 'for use' claim is infringed by a product packaged and labelled for that use; a Swiss-type claim is infringed by manufacture of a medicament for that use. VaudRx should align the claim category with its commercial product and with the national phase in Switzerland, where therapeutic methods are also excluded.
3. What support and clarity problems remain after the amendment, and how should VaudRx respond to the Art. 84 objection?
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Even after removing 'optimized' and 'real time', the claim contains a functional limitation: the dose is adjusted in response to a measured biomarker level. Art. 84 EPC requires clarity and support. The claim must make clear how the biomarker is measured and what adjustment is made; otherwise it covers any adjustment, including arbitrary changes, and may be unsupported across its breadth.
The applicant should limit the claim to the disclosed embodiment: biomarker Z, a measured level, and an adjustment within 3 to 7 mg/kg, optionally with a specified direction of adjustment if disclosed. If the specification provides only one example, the claim should not extend to all biomarkers or all adjustment algorithms. The description can be amended to explain the relationship between the measured level and the dose, but no new matter may be added.
A practical response is to file a marked-up claim set and a detailed basis explanation, not merely an attorney's argument. If the EPO maintains the objection, fall back to a dependent claim combining 5 mg/kg with biomarker Z. That preserves the commercial core while reducing the risk of an undue-burden objection.