UPC vs. EPO Oppositions: Lessons from Recent UPC Case Law

A European Patent Office (EPO) opposition is often the first line of defense for a party seeking to invalidate a European patent. Oppositions must be filed within nine months of the patent’s grant, and they offer a centralized way to revoke or limit the patent in all designated states. With the Unified Patent Court (UPC) now providing a parallel central revocation mechanism (with no deadline) for UPC member states, it was inevitable that some patents would face both an EPO opposition and a UPC revocation/infringement action at the same time. The interplay between these proceedings has quickly become a critical issue, raising questions of stays, inconsistent outcomes, and tactical timing. Case law from 2024–2025 illustrates how the UPC and parties are managing double-tracked disputes.

UPC’s ‘No Stay’ Presumption

The UPC Agreement (Art. 33(1)(b)) and Rules of Procedure (Rule 295(a)) permit the court to stay proceedings if the patent is also involved in an EPO opposition (including on appeal) and a decision “may be expected to be given rapidly” in that other proceeding. In practice, the UPC has set a high bar for what counts as “rapid.”

In Carrier Corp. v. Vicot (UPC CoA 22/2024, May 28, 2024), the appellant sought to pause a UPC revocation action because they had accelerated a parallel EPO opposition on the same patent. The UPC’s Court of Appeal refused, upholding the first-instance decision not to stay. The Court emphasized as a general principle that it will not stay a UPC case merely because an opposition is pending. The mere existence of a parallel EPO proceeding “is not sufficient to allow an exception” to the UPC’s mandate to adjudicate.

In the court’s view, concurrent UPC and EPO decisions on the same patent are “not irreconcilable”; if they diverge, the EPO’s later ruling will simply prevail to the extent it affects the patent’s status. This stance reflects the UPC’s confidence that it can proceed without undermining legal certainty: a European patent might be revoked by the UPC in UPC countries, yet survive in others, or vice versa, but ultimately the EPO’s final say (especially if it revokes the patent Europe-wide) will prevail and can be taken into account in enforcement. In short, the UPC signalled that it won’t wait for the slower EPO process except in clear-cut situations.

First Instance EPO Decisions

Later in 2024, the UPC Court of Appeal refined the application of Rule 295(a) in Meril Life Sciences v. Edwards Lifesciences (UPC CoA 551/2024, Nov. 21, 2024). In that case, Edwards had sued for infringement of a Unitary Patent, and Meril countered with both a UPC revocation counterclaim and an EPO opposition (filed in parallel). Meril asked the UPC’s Nordic-Baltic regional division to stay the infringement case until the EPO’s Opposition Division decided validity.

The local division refused, reasoning that a final EPO decision (after appeals) could not be obtained quickly. On appeal, the UPC’s higher court found this was too strict. Crucially, by the time of the appeal hearing, the EPO had indeed accelerated the opposition (after being notified of the UPC case) and scheduled an oral hearing for January 17, 2025, meaning a first-instance EPO decision was imminent (the UPC trial was also set for mid-January 2025).

The Court of Appeal held that the lower court erred by focusing solely on the speed of a final EPO outcome. Rule 295(a) does not require that the entire EPO appeal process will conclude rapidly. It is enough that the Opposition Division’s decision can be expected soon. In effect, the Court of Appeal signalled that if an EPO first-instance ruling is around the corner (here just two months away), a stay may be justified to avoid the UPC potentially rendering a decision just days before the EPO does. Importantly, the appellate panel also clarified that while new facts/evidence cannot be introduced on appeal, new legal arguments based on the existing record are allowed. This allowed Meril to argue on appeal why the stay criteria were met.

So, where do things stand? The general rule is still no stay for EPO opposition, but the UPC will flex that rule if an EPO decision is truly imminent. Parties can leverage this by actively seeking acceleration at the EPO. In Carrier, the party did request EPO acceleration, but apparently the timing still wasn’t fast enough. In Meril, even without a party request, the EPO expedited the opposition upon learning of the UPC case, demonstrating a new coordination mechanism. As of 2024, the EPO will automatically accelerate opposition proceedings if informed of parallel court actions in the UPC or national courts. In Meril’s case, the EPO’s fast-track (oral proceedings set within 10 months of filing the opposition) created the circumstances that met the UPC’s “rapid decision” threshold. This shows a high degree of interplay – the EPO and UPC both adjusting procedures to handle parallel litigation efficiently.

Coordinating Outcomes vs. Conflicting Outcomes

One potential benefit of parallel proceedings is the opportunity for consistency, a patentee seeing the way the wind blows at the EPO might adjust its case in the UPC, or vice versa. Indeed, the UPC encourages patentees to submit aligned claim amendments if an EPO opposition leads to a narrowed claim set, in order to harmonize outcomes. This was illustrated in two 2024 UPC revocation actions concerning e-cigarette technology, both filed by NJOY (Netherlands) against patents owned by competitors:

In the Juul Labs case (UPC 312/2023, Feb. 28, 2025, concerning EP 3504989), an EPO Opposition Division had already decided (at first instance) to maintain the patent in amended form. Because that EPO decision came early enough during the UPC proceedings, the defendant (patent owner) was able to introduce an auxiliary claim request matching the EPO-maintained claims into the UPC case. The UPC panel ultimately found the granted claims invalid (added matter) but upheld the patent on the exact same amended claims that the EPO had allowed. In other words, the UPC and EPO reached a convergent result. Notably, the EPO’s Boards of Appeal later went further and revoked the patent entirely for added matter). This case demonstrated that parallel proceedings can, if timed well, result in consistent claim scope across jurisdictions.

In the VMR Products case (UPC_CFI_310/2023, Jan. 22, 2025, concerning EP 3613453), an EPO Opposition Division also maintained the patent with a narrowing amendment, but the timing was less ideal. The EPO’s decision came after the defendant had filed its initial case papers in the UPC, and only shortly before the UPC’s interim conference. The UPC judges invited the patent owner to submit a new auxiliary request to reflect the EPO’s allowed claims and gave both parties a chance to comment on admitting this late amendment. The claimant (NJOY) objected to the new claim set as belated. Ultimately, the UPC refused to accept the late-filed amended claims into the case, noting that the patent proprietor could have pursued alignment earlier and that the proposed claims likely wouldn’t cure the UPC panel’s concerns on inventive step anyway. The UPC went on to find the patent partially valid in a different form. It upheld certain dependent claims individually as new independent claims combined with claim 1, while ruling claim 1 (as granted) obvious. In effect, the UPC allowed a differently scoped claim set compared to the EPO. The two first-instance decisions resulted in the patent having “a different scope… in UPC countries” versus non-UPC countries. If those outcomes hold through appeals, it raises a novel situation: what is the enforceable claim scope in UPC countries when the UPC and EPO have approved two non-identical sets of claims? There is no precedent yet on this question. One view is that once the EPO’s decision is final (after any appeal), the official patent claims will be those sanctioned by the EPO, potentially mooting the UPC’s differing determination. The UPC panel in VMR did note that even if they had admitted the EPO’s amendment, it would not have changed their finding on lack of inventive step, suggesting the UPC was comfortable diverging.

This highlights a strategic consideration for patentees to avoid a tangle, one might proactively align claim strategies in both venues as early as possible (even anticipating likely EPO amendments in the UPC case). Meanwhile, accused infringers can take advantage of any inconsistency by arguing, for example, that a UPC revocation decision on different claims should limit enforcement until the dust settles.

Key Takeaways from UPC – EPO Parallel Cases

So far, UPC judges have demonstrated respect for EPO proceedings (e.g., by allowing alignment when timely and considering stays when truly imminent decisions loom) but have been unafraid to decide validity independently on the record before them. Indeed, the UPC is not legally bound by an EPO opposition outcome, especially if the timing misaligns.

A European patent could thus be upheld in one forum and struck down in another, at least temporarily. In the long run, a final EPO appeal decision (which has effect in all EPC states) will govern what claims, if any, survive.

Parties must therefore weigh the pros and cons of running fights on two fronts. There is no prohibition on doing so. One can simultaneously pursue an EPO opposition and a UPC central revocation. In some instances, different entities took the two routes (e.g., a competitor filed the opposition while another party filed the UPC case). However, a single party might also double up efforts if circumstances warrant – for example, if new prior art emerges after the nine-month opposition window, a party who missed the window can file a UPC revocation action at any time, or if an opposition is ongoing but the challenger wants a faster or broader (UPC-only) attack, they might not want to rely on the EPO alone. The UPC and EPO proceedings each have distinct advantages, which often leads parties to use both in parallel to maximize their chances.

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