Executive Summary

As a result of decision T0107/09, issued by an EPO Technical Board of Appeal on 12 July 2012, practitioners outside Europe and especially in the US should be careful to ensure that biological samples are deposited on or before the priority date. In this case, the deposit was made in between the US priority filing and the subsequent EP filing. Although that was allowable under US practice, the EPO ruled that under the EPC the deposit was made too late for the invention to be sufficiently disclosed in the priority application. The US priority date was therefore lost, bringing an intervening publication into play. As a result, the EP patent was found to be invalid for lack of inventive step.

Although biological deposits are used less frequently these days, this decision represents a potential divergence between US and EP practice regarding when a biological deposit needs to be made. To be safe, US practitioners are therefore advised to file any deposits before the relevant priority application.


European patent No. EP0555880 relates to, among other things, soluble ligands to the CD40 counter receptor (CD40R) molecule, the monoclonal antibody MR1 and a hybridoma producing MR1. Claim 1 of the granted patent referred to the hybridoma, and a sample of the hybridoma was deposited with the ATCC under accession number HB 11048. Of particular importance to this decision was the fact that the biological sample was deposited after the US filing date but before the EP filing date.

It should be noted that, in view of the publication date of the European patent, the provisions of the EPC 1973 apply and any specific provisions mentioned herein refer to those under the EPC 1973.

Reasons for the decision

The Board held that the patent in question could not claim priority from US application No. 20050127046 because the assessment of the disclosure content of the earlier application should be made in accordance with the EPC and its case law. In particular, Article 87(1) EPC states that the right to priority can only be enjoyed if the earlier and the later applications disclose the same invention. Elaborating on this, the case law establishes that subject-matter is disclosed only if a person skilled in the art can derive it directly and unambiguously from the earlier application as a whole. Furthermore, a disclosure must be “enabling” for it to be detrimental to novelty. Thus, Article 87(1) EPC requires that the earlier disclosure allows a person skilled in the art to carry out the invention.

It was held that the antibody MR1 is indispensable for the skilled person to be able to work the present invention. However, the hybridoma that produced this antibody was not available to the public at the date of filing the US application. The Board held that the ’written’ disclosure in the US application was, therefore, not sufficient for a skilled person to carry out the invention and that a biological deposit of the hybridoma was necessary in order for the invention to be sufficiently disclosed.

There are no explicit provisions in the EPC as to when a biological deposit has to be made in relation to an earlier application in order to ensure that a right of priority may arise from it. On the other hand, the Enlarged Board of Appeal has previously held that the requirement of sufficiency of disclosure in relation to an earlier application from which priority is claimed must be complied with at the filing date of the earlier application. Thus, if a deposit of biological material is required in order to fulfil the sufficiency requirement, this deposit must be made no later than the filing date of the earlier application, i.e. the priority date.

The appellants had argued that the US application fulfilled the requirements of US patent law for establishing a filing date, which, in particular, does not require that the biological sample be deposited at the latest by the filing date of the application. Therefore, the US application should be considered a regular national filing under Article 87(1) EPC and, consequently, the European application should be entitled to priority under Article 87(2) EPC. However, the Board held that Article 87(1) EPC provides only that it is the date of filing the earlier application which is established under national law. It cannot be inferred from Article 87 EPC that the standards of national law are to be applied in relation to other requirements of a potential priority application. Thus, the assessment of whether the earlier and the later applications disclose the same invention is carried out in accordance with the EPC.

Summary of the decision

The Board concluded that the failure to deposit the hybridoma cell line producing the antibody MR1 at the latest by the filing date of the US application meant that the US application did not disclose the invention in a manner sufficient for a person skilled in the art to carry out the invention. Thus, the US application and the European patent do not disclose the same invention. Consequently, the requirements under Article 87(1) EPC for claiming priority were not met. Claim 1 of the European patent cannot, therefore, enjoy priority from the US application and this means that the date for determining the state of the prior art pursuant to Article 54(2) EPC is the filing date of the European application. As a result, document D3 was considered to be prior art in accordance with Article 54(2) EPC and the Board went on to find that the European patent lacked inventive step in view of D3.


This decision highlights that, in order for a European application referencing a biological sample to be able to claim priority from an earlier filed foreign application, the biological sample must have been deposited before the filing date of the earlier application. It is therefore crucial that patent attorneys bear in mind the need to comply with these differing requirements.