UPC Weekly brings you timely, thoughtful and joined-up insight into the evolving landscape of patent litigation at the Unified Patent Court.
2026 Week 29
This is what a Court of Appeal is for – dealing with a genuine uncertainty in how to apply the law and a real inconsistency between decisions of different first instance divisions of the UPC. The wrinkle at hand is how the UPC should deal with the validity of the dependent claims of the granted patent, where the main claims are invalid. The guidance provided this week by the UPC Court of Appeal (CoA) pretty much fully addresses all of this and sets out a playbook for the patentee defending the patent against invalidity attacks at the UPC.
The case at issue is yet another one between Fujifilm and Kodak relating to lithographic printing. In this dispute, Fujifilm sued Kodak for infringement in Germany and UK based on EP 3476616 with the now-familiar arguments for long arm jurisdiction.
Mannheim LD – patent is invalid
In Fujifilm v. Kodak (UPC LD Mannheim, 2 April 2025), the LD decided that the patent as granted was invalid for lack of inventive step. This applied directly to the German designation of the patent and so the patent was revoked there. Based on the principles of long arm jurisdiction, the patent was later held to be invalid between the parties in respect of the UK.
Fujifilm defended against the invalidity attack by filing three auxiliary requests (ARs). AR1 and AR2 added some features to claim 1 and AR3 dealt with an added matter attack against dependent claim 6 but this AR was not invoked. Fujifilm also set out reasoning as to why various dependent claims as granted were valid over the counterclaim for revocation.
Fujifilm argued that the court should consider the validity of the dependent claims as granted, irrespective of whether specific auxiliary requests are filed to amend the claims in this way. This is based on Article 65 UPCA, which says that the court may revoke a patent “either entirely or partly”. Also, if the grounds for revocation affect the patent only in part, the patent shall be limited by a corresponding amendment of the claims and revoked in part.
The LD’s position was that this was all well and good, but the mechanism for partial revocation of the patent must be that the patentee should amend the claims to what is valid. The process for doing this is set out in R. 30 RoP, which allows the patentee to file amendments to the claims as granted as a main request or as ARs.
For anyone familiar with EPO opposition procedure, this is exactly as you would expect. The EPO wants to be presented with a set of amended claims that is wholly valid in order to decide to maintain the patent in amended form.
Central limitation request filed at the EPO
After the decision of the Mannheim LD that the patent was revoked for Germany, Fujifilm filed a request for central limitation of the patent at the EPO based on Article 105a EPC. The amendments filed were to add the features of dependent claims 2, 6 and 7 to claim 1.
When the EPO receives such a request for limitation, it must examine the amendments, but only for clarity, added matter or broadening of the claim scope. The EPO will not examine issues of substantive patentability. However, the EPO is not allowed to process a request for central limitation if there are pending EPO opposition proceedings.
In this case, unsurprisingly, third party observations were filed at the EPO, objecting that the request for limitation should be deemed inadmissible in view of the decision of the UPC to revoke the patent. Further objections were included, relating to the clarity of the amended claims.
The EPO decided that they could proceed with the limitation request because UPC proceedings are not EPO opposition proceedings. The pendency of a UPC counterclaim for revocation would not stop the EPO from allowing a central limitation of the patent. The amendments were allowed and the decision to limit the patent took effect in November 2025 – see the EP 3476616 B3 publication. The effect of a central limitation of the patent at the EPO is that the amendments to the claims have retroactive effect back to the date of grant of the patent.
CoA – amended patent is valid and infringed
In the meantime, Fujifilm appealed at the UPC, with their statement of grounds of appeal being filed in August 2025 (before the EPO formally allowed the central limitation). The appeal was based on the patent as limited at the EPO, not based on the claims decided on by the LD.
In Fujifilm v. Kodak (UPC CoA, 13 July 2026), the CoA decided that the claims as limited were admissible, valid and infringed in Germany. The UK infringement part was dismissed for lack of substantiation of infringing acts (similarly to the outcome of a separate case in the same area of technology, see UPC Weekly 2026 w24).
Defending the dependent claims as granted
The CoA decided that it is fine for the patentee to defend the dependent claims as granted, without necessarily having to formalise this with auxiliary requests. They acknowledged that this is different to the approach of the EPO in opposition proceedings.
The CoA’s reasoning is based on Article 65 UPCA directing that a patent should not be revoked in its entirety if it is only partially invalid. However, this is not a free-for-all applying to all possible permutations of claim dependencies. The patentee must substantiate which dependent claims are valid and in which combinations. Also, the number of positions adopted must be reasonable in number (as for the number of ARs allowed, although this is a bit of a moveable feast depending on the case).
Of course, one way to retreat to the scope of a dependent claim is to file an AR. But the CoA explained that this is not essential. There is a distinction between making amendments to the claims, in the form of an AR, which would require an explanation from the patentee as to why the amendment satisfies Articles 84 and 123 EPC. Such explanations would not be needed for mere combinations of claims as granted, because the clarity of these claims is not in play after grant.
So, how should a patentee defend against invalidity attacks? Defending the independent claims of the patent as granted is fine and not changed. But where there are fallback positions that are merely pre-existing dependent claims, these can be identified in the defence to revocation and substantiated, without filing ARs. And, in addition, ARs can be filed that introduce new amendments. This opens up a new framework for the patentee to defend the patent, but does not lessen the burden of getting these positions established and argued – the UPC’s front loading approach applies here too.
A further point not fully bottomed out is whether the patentee can bounce between the dependent claims as granted and ARs, in terms of the ordering of the requests. In principle, any order seems allowable, so long as it is clear. So, the patentee could defend the independent claims as granted, then AR1 with an amendment to claim 1 from the description, then dependent claim 2 as granted, and so on.
Patent back from the dead?
The use of the EPO’s central limitation procedure here is interesting. Kodak asked the CoA to disregard the amendments made to the patent at the EPO. But a limitation made to the patent in this way has retroactive effect and the CoA acknowledged that they have no discretion to ignore it.
Another point, not mentioned here by the CoA, is that the central limitation of the patent also applies to the UK part of the patent, neatly avoiding difficult discussions about which claims in the UK the CoA is considering for validity.
In this case, the CoA left open the question of whether, in different circumstances, using EPO central limitation in parallel to UPC proceedings would be “contrary to due process”. For example, what if the patentee had amended the patent at the EPO in a manner not foreshadowed at all in the first instance UPC proceedings?
If things have gone very wrong from the patentee’s perspective at first instance, and in case getting in new amendments to the claims may face admissibility issues at the CoA, then using EPO central limitation may be an approach worth considering.
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