UPC follows EPO’s ‘rebuttable presumption’ of priority right

In 2023, the EPO’s Enlarged Board of Appeal issued the G1/22 and G2/22 decisions which decided that there is a ‘rebuttable presumption’ that the applicant has the right to claim priority. This means that even if the priority application has different applicants and no facts have been provided in support the priority claim, the EPO will presume the priority claim is valid, unless this presumption is rebutted by the opponent. The EPO’s Enlarged Board of Appeal indicated that this would require the opponent to provide specific facts that support serious doubts as to the subsequent applicant's entitlement to priority. Consequently, the burden of proof at the EPO now lies with the opponent to disprove the applicant’s entitlement to the priority claim.

The Paris Central Division followed the European Patent Office (EPO)’s decision that there is a ‘rebuttable presumption’ of the patent proprietor’s right to claim priority in the recent first instance decision issued on the Meril v Edwards Lifesciences revocation and counter-claim for revocation cases (UPC_CFI_255/2023 and UPC_CFI_15/2023).

The applicant named on Edwards’ patent differed from that of the patent’s earliest priority application. One attack on the patent was that it lacked entitlement to the earliest priority claim as a consequence. Although the rights in the patent were expressly assigned, the assignment in question did not separately assign the right to claim priority. The right to claim priority is, however, recognised as a separate right, which was argued as not having been assigned in the assignment. 

When analysing the question of whether the right to claim priority has been assigned alongside the other rights in the patent, the Panel stated that assignments of patent applications “usually fail to distinguish between the two rights”. The Panel cited the G1/22 and G2/22 decisions and applied the ‘rebuttable presumption’ standard, finding that because of the evidence of transfer presented by the defendant, and the lack of specific evidence provided by the claimant to suggest that the original applicants intended to retain the priority rights instead of transferring them with the rights to the title of the patent, or that the priority rights had been assigned to another party presented by the claimants, the presumption of validity was not rebutted. 

Ultimately, the priority claim was however found to be invalid on substantive grounds due to the Panel finding the claimed subject matter not directly and unambiguously derivable from the earliest priority document, meaning that the UPC Panel implicitly adopted another EPO case law principle enshrined in the famous Enlarged Board of Appeal decision G2/98. 

Whilst UPC Judges are not bound by EPO case law, this decision is another example where Judges have drawn on established EPO principles when deciding on issues before them.  Nevertheless, it will be interesting to see if in future cases UPC judges will ultimately determine questions of substantive national/UPC law when it comes to issues of assignment of priority rights – ultimately the Enlarged Board held in the G1/22 and G2/22 decisions that that the EPO was not well equipped to deal with such issues and it was down to national courts to decide such questions – but it appears that in this case, the UPC judges did not pick up that particular gauntlet.