Redrafting US medical treatment claims having the typical wording “A method of treating disease Y in a patient, said method comprising administering compound X to said patient” into EPO allowable medical use claim format as per the wording “Compound X fur use in the treatment of disease Y in a patient” is not a big deal and daily business when US style applications are filed in Europe.

Such a redrafted claim provides protection for the treatment of the specific disease Y, similar to the original US claim, but does not cover further diseases for which compound X could similarly be used as a medicament. To cover the latter, the EPO’s so-called “first medical use” claim format having the wording “Compound X for use as a medicament” is the right choice and allowable if there is support under Art. 123(2) EPC for such claim wording in the original filed application. Said support under Art. 123(2) EPC could be a single and sufficient sentence in the description such as “Compound X can be used as a medicament, including but not limited for the treatment of disease Y”. Importantly, unlike in the US, support and disclosure under Art. 83 EPC, corresponding to the US enablement requirement, is not an issue at the EPO for said broad first medical use claim, even if there is only data for treating a single specific disease Y. 

However, the recent decision T 0419/16 of February 3, 2022 shows that what is all very well in theory does not work in practice if supporting wording of the first medical use claim is missing in the original US style application the European patent application has been based on. As noted in said decision with regard to art. 123(2) EPC: “In the absence of literal basis for a first medical use claim in the application as filed, adding claims in this claim category resulted in added subject-matter, even if it might have been possible to draft such a claim at the time of filing.”

So while a first medical use claim may not have a chance in the US, it can be granted in Europe and should therefore be included in the European claim set, which in practice means that to overcome the hurdle of Art. 123(2) EPC, support, e.g. as per the sentence “Compound X can be used as a medicament, including but not limited for the treatment of disease Y”, must be included in the originally filed (e.g. US) application.