Although not unique to life sciences, priority entitlement has proved to be a key issue in a number of significant life science cases at the European Patent Office (EPO). For example, in 2019, EPO Opposition Divisions revoked the Broad Institute’s CRISPR patents EP2764103, EP2784162 and EP2896697 after finding that none of these patents was entitled to priority.

This finding arose because the applicants named on the priority application were different to those named on the subsequent European patent application. The patentee could not prove that the right to claim priority had been validly transferred, so the applicants named on the European patent application were not considered to be the “successors in title” to the applicant(s) named on the priority application. This meant that entitlement to priority was lost without considering the actual contents of the priority and European applications, and resulted in a finding of lack of novelty over a reference that would not otherwise have been prior art.

In G1/22 and G2/22, the Enlarged Board of the EPO (EBA) considered the requirements for claiming and transferring priority rights in Europe. They took an (uncharacteristically) pragmatic view which has changed EP practice. Instead of placing the onus on the applicant/patentee to prove that priority rights had been validly transferred to them, the EBA ruled that the legal requirements for transferring the right to claim priority were minimal and there was a rebuttable presumption that priority was validly claimed. This presumption requires the challenger to prove that priority rights have not been transferred to the applicant/patentee and makes it much harder to challenge the validity of a priority claim.  

As a result, we are likely to see fewer attacks on the formalities of priority claims in opposition and appeal proceedings at the EPO. This change in approach is illustrated by the Board of Appeal decisions on the Broad Institute CRISPR patents revoked by the Opposition Division. In all three cases (T2689/19, T2360/19, and T2689/19), the Board of Appeal overturned the Opposition Division’s findings and ruled that priority entitlement was valid in accordance with the principles of G1/22 and G2/22.

The use of post published evidence to show that an invention achieves a technical effect has also come under recent scrutiny at the EPO. Demonstrating that an invention achieves a technical effect is often important in EPO proceedings to establish that the invention involves inventive step. Many previous EPO decisions have ruled that the original patent application needed to make a technical effect “plausible” or “not implausible” in some way before post-published evidence could be taken into account.

In G2/21, the EBA decided that at least for the purposes of inventive step, an applicant or patentee was allowed to file additional experimental data to show a technical effect if a skilled person would derive the technical effect as being encompassed by the technical teaching of the originally filed application. This removes the need to consider any form of “plausibility” or “implausibility” test when deciding whether to admit post-published evidence to show an inventive step. 

However, the EBA themselves noted the “abstractness” of the new test and the details of how the test will be implemented in practice by the EPO remain to be established. The EBA’s reasoning was limited to inventive step and the new test does not apply to post published evidence for the purposes of sufficient disclosure. This is particularly significant in the life sciences, where evidence of a technical effect that is relevant to a therapeutic application is generally required in order for second medical use claims to meet the requirements of sufficient disclosure. It will remain challenging to use post-published evidence at the EPO in these circumstances.

The opening of the Unitary Patent Court (UPC) in June 2023 was a significant landmark in the development of European patent law. The approach of the UPC to different patentability issues is now being slowly revealed by the issuance of more and more UPC decisions. A key decision for life sciences was the Sanofi vs Amgen Decision of July 2024 (459505/2023 UPC_1/2023). This was part of a long running global patent battle between the parties and was the first decision on patent validity by a UPC Central Division. 

The case concerned anti-PCSK9 antibodies, which are used in the clinic for the treatment of cholesterol-related disorders. The approach taken by the UPC in assessing the key issue of inventive step was a matter of great interest to practitioners and in particular, whether or not UPC used the same “problem and solution” analysis as the EPO. In fact, the UPC did not use the problem and solution approach and employed an approach more reminiscent of the German courts to find the claims non-inventive. Instead of starting the analysis by identifying the closest prior art document, the UPC simply identified “a realistic starting point”, without worrying about whether or not it was the closest. The UPC then identified an “underlying problem” addressed by the invention from the patent description. 

Again this is different to the classical EPO problem and solution approach, which requires the objective technical problem to be distilled from the effects arising from differences between the invention and the closest prior art document. The UPC then assessed whether the solution disclosed in the patent to the “underlying problem” was obvious from the “realistic starting point” and decided that it was. Opposition proceedings are ongoing at the EPO, and it will be interesting to see if the EPO reach the same conclusion on inventive step using their approach. 

It will also be interesting to see if other parts of the UPC, and in particular, the UPC Court of Appeal adopt the same approach as the UPC Central Division. In this decision, the UPC also ruled that the claims in a patent should be interpreted with aid of description in accordance with Art 69 EPC and its protocol. This issue is very alive at the EPO and is currently the subject of a referral to the EBA (G1/24). It remains to be seen whether the EPO will take the same approach as the UPC.

As well as the role of the description in interpreting claims (G1/24), the next year is likely to see a further EBA decision on the prior art effect of products that cannot be analysed or reproduced (G1/23). Both of these upcoming EBA decisions will impact on patent practice in the life sciences. We can also expect more UPC decisions that provide more detailed information about how the UPC is intending to assess patentability issues. 

Away from the UPC and EPO, the European Union is currently working to reform its supplementary protection certificate (SPC) regime and establish a new unitary SPC to run alongside the unity patent. A reformed SPC regime would be of great interest to the pharmaceutical and life sciences sector. European patent law in the life sciences therefore remains dynamic and we will continue to report on future legal developments relevant to the life sciences.

Nick Sutcliffe is a partner, patent attorney and litigator specialising in life sciences at Mewburn Ellis in Cambridge, UK.