On 6 November 2020, the Technical Board of Appeal (TBA) issued a written decision in case T 844/18, which concerned whether or not the Broad Institute’s patent (EP 2 771 468) relating to CRISPR gene editing technology could validly claim priority from several US provisional applications. In summary, the TBA confirmed that the applicable rules governing the entitlement to priority remain unchanged. As a result, the priority had not been validly claimed and the patent in question was revoked for lack of novelty due to intervening prior art. The outcome does not come as a surprise, since the TBA made known its decision following the oral hearing which took place in January 2020 (see our summary in the Patent & Pharma update from February 2020).

Under Article 87(1) EPC, any person who has duly filed an application for a patent or their successor in title shall enjoy a right of priority during a period of twelve months from the date of filing of the first application (emphasis added). Article 87(1) EPC corresponds to Article 4A of the Paris Convention for the Protection of Industrial Property.

The disputed issue, as summarised by the TBA, was as follows: “A and B are applicants for the priority application. A alone is the applicant of the subsequent application. Is this priority claim valid even without any assignment of priority right from B to A? The appellants say that the answer is ‘yes’ and the respondents that the answer is ‘no’.” The TBA sided with the respondents and in doing so decided the following points:

  • EPO are empowered and obliged to assess the validity of a priority right claim;
  • “Any person” under Article 87(1) EPC refers to all persons listed as applicants for the priority application, such that all persons listed as applicants for the priority application, or their successors in title, must be listed as applicants for the subsequent application (reaffirming the so-called “all applicants” approach); and
  • It is the Paris Convention and not national law which determines who “any person” is.

The TBA reiterated that Article 87(1) EPC has been consistently interpreted by the EPO since the inception of the European patent system and the practice is based on a reasonable interpretation of the legal provisions in question. The TBA also emphasised that the bar for overturning a long-established case law and practice should be a high one because of the disruptive effects a change may have.

A policy reason put forward in support of the appellant’s position was that a mistake in the formality of correctly naming the applicants should not lead to the revocation of the patent (echoing the remarks of Birss J in Accord Healthcare v Research Corporation Technologies [2017] EWHC 2711 (Ch)). The TBA responded that the present case is an example of a deliberate choice of the appellants rather than a mistaken omission and, also, that a formal requirement cannot be merely disregarded or ignored even if the consequence of its non-compliance can be a revocation of a patent. The TBA also noted the different context in which the remarks were made in the English High Court case (which dealt with a distinction between legal and equitable title).

The consequences of non-compliance with rules pertaining to claiming priority are significant and may result in invalidating an otherwise valid patent. With that in mind, considerable thought should be given to naming applicants on the priority application and the effect of any subsequent assignments of priority rights during the priority year to minimise future challenges to priority entitlement.

Monika Klajn

Monika Klajn
Senior Associate, London
+44 20 7466 7604

Alex Freelove

Alex Freelove
Senior Associate, London
+44 20 7466 7452

Jonathan Turnbull

Jonathan Turnbull
Partner, London
+44 20 7466 2174