Last week the hearing for appeal proceeding (T 844/18) relating to European Patent 2771468 B1, regarding the gene-editing technology CRISPR-Cas9, held by The Broad Institute, Inc., Harvard University and MIT, took place at the European Patent Office (EPO) in Munich.

The patent was granted in early 2015, but was revoked by the Opposition Division in an intense opposition proceeding owing to a lack of novelty over intervening prior art, which became relevant due to a loss of priority right: this arose because the priority applications named a different set of applicants from those named when EP 2771468 was filed.

The patent application from which EP 2771468 was ultimately granted was filed as a PCT application (WO2013US74819) claiming priority from 12 U.S. provisional applications. Four of the provisional applications named a Luciano Marraffini as co-applicant but he was not identified as an applicant in the PCT application. A formal assignment of Dr Marraffini’s priority rights to Rockefeller University was effected, but after the PCT application had been filed.

As well established currently under the European Patent Convention (EPC) and under the usual interpretation of Art. 87(1) EPC, the PCT-application and hence the EP-application was not entitled to priority because the succession of title had occurred after the filing of the PCT application.

Topics of debate

It was thus exactly this long-standing interpretation that was put under scrutiny during the appeal proceeding. In the grounds of appeal (which were 97 pages long) the patentee raised three major questions for discussion during the oral proceedings, namely:

  1. Is the EPO entitled to asses priority rights?
  2. Is the current interpretation of the “any person who duly filed” according to Art. 87(1) EPC flawed? Should it be interpreted as “anyone of the person who duly filed” enjoys the right to priority?
  3. Should the phrase “any person who duly filed or his successor in title” be interpreted according to the national law in which the priority document was filed?

Point 2 in particular, as might be imagined, raised many eyebrows, as it implied that 137 years of existing practice under the Paris Convention and more than 40 years under the European Patent convention (EPC) was mistaken. Further, that practice is currently followed in most PCT states, with the exceptions of some states like US, China and Brazil.

In the Patentee’s view, however, Question 1 should have been answered with a No, and Questions 2 and 3 with a Yes. The Opponents were clearly and strongly of the contrary view.

Timeline of Proceeding

The Appeal proceedings started on a Monday and was set for five days. The Board of Appeal was composed by three technical members and two legal members.

On day one, the participants discussed the literal interpretation of the term “any person”. On the second day, the interpretation of the term “any person” was discussed in light of its context and purpose in Art. 87(1) EPC.

In the morning of the third day, the Appeal Board gave as a preliminary non-binding opinion that at least question number 2 might have to be referred to the Enlarge Board of Appeal (EBoA) as it appeared to concern a fundamental question of law. This was energetically attacked by the Opponents who saw no reason to refer the decision to the EBoA, arguing that the Board of Appeal was in the position to make a decision. The Opponents also argued that, apart from this case, there was no decision by other Boards of Appeal that diverged from the usual interpretation of “any person” (which might have been reason for referral to the EBoA).

Day three, Wednesday, continued with a discussion regarding the entitlement of the EPO to assess priority (Point 1). On day four Point 3 was discussed.

After a long break on Thursday afternoon, the Board of Appeal concluded that it could make a decision without referral to the EBoA. It upheld the decision of the Opposition Division to revoke the patent and announced that it rejected all three arguments of the Patentee.

Board’s decision

The Board concluded that:

  1. Indeed, the EPO is entitled to assess whether a party has a right to priority.
  2. The meaning of “any person who duly filed” in Art. 87(1) EPC has to be interpreted as it is currently interpreted, namely, that all of the applicants named in the priority application(s) or their successor in title have to be named in the subsequent application that claims that priority. The right of priority is a common right shared by all applicants, which cannot be singularly divided for the purpose of claiming priority.
  3. National Law does not need to be considered when assessing priority rights. The EPO has all the necessary means (the PCT, the EPC and case law) to make such an assessment.

The further contention by the Patentee—that these questions should be referred to the EBoA (briefly discussed on the Wednesday morning)—was dismissed by the Board of Appeal, which considered itself capable of deciding. It is thus possible that the Patentee may file a petition for review, if it considers that its right to be heard regarding a possible referral has not been respected—and hence perceives a procedural violation in this matter by the EPO.

However, the decision as it was made stands, even though we must await the written decision for it to be entirely official.


The assessment of priority rights remains unchanged from current practice and both European and non-European practitioners should continue to take special care that the applicants named in the priority document(s) coincide with the applicants named in the priority claiming document, or that a transfer of priority right has been effected before the filing of the subsequent application.

Personally, I learned a great deal from attending these proceedings—both in seeing how a single article can be discussed for 4 days and with what ease some of the best practitioners around manage to discuss complex legal matters. I am also relieved, because it appears this won’t become an issue during my EQE examinations.

This story, however, is not over! The Patentee lost a battle, but still has many more patent applications in its portfolio.


Riccardo Bellingacci