UPC Narrows Stay Requests as EPO Oppositions Move Faster

On 17 February 2026, the UPC Court of Appeal in bioMérieux v Labrador Diagnostics refused to stay a revocation appeal because of parallel EPO opposition proceedings, and also refused to extend the deadline for the statement of grounds while waiting for the EPO oral hearing. The signal is straightforward: the mere fact that the same European patent is being contested before both the UPC and the EPO does not automatically trigger a “wait for Munich” logic. A stay remains discretionary, and the court is looking at the concrete balance of interests rather than at parallel opposition as a standalone fact.

This matters well beyond the revocation appeal itself. For parties preparing infringement claims, validity defences or even a preliminary injunction during the overlap period, the procedural calendar is being reset. The UPC is showing little appetite to yield its timetable to the EPO, while the EPO has made its own acceleration practice in parallel court cases far more operational in public guidance. The dual-track system is still there, but the room for passive waiting is shrinking.

This order sharpens an existing no-easy-stay line

If this order is read simply as “the UPC refused a stay”, the more useful point is missed. The UPC had already signalled caution about pausing cases because of parallel opposition proceedings, but the Court of Appeal has now made the threshold feel more concrete. The existence of an EPO opposition is not enough by itself. Even the prospect of a relatively near EPO development will not automatically persuade the court to stop. What counts is whether a stay is actually justified in light of procedural efficiency, case progress, party interests and the tools already available inside the UPC framework.

That reduces a zone of strategic ambiguity. Many parties would naturally think that, if an EPO oral hearing is approaching, the UPC might simply hold the file for a short period and wait for the result. That route has not disappeared, but it now looks noticeably narrower. The court appears more interested in whether the case can continue sensibly, whether parties can still comment later on EPO developments, and whether there is a genuine present need to stop rather than a tactical preference to do so.

The real change is in PI timing and evidence front-loading

The order does not set out a new substantive test for preliminary injunctions, but its procedural message matters directly for PI strategy. If the Court of Appeal is unwilling even to extend a deadline for grounds while awaiting an imminent EPO event, that tells parties something important: the UPC does not want core litigation choices postponed simply because opposition proceedings may soon become more informative. A patentee thinking about a PI can no longer rely too heavily on the hope that a coming EPO development will later stabilise the validity narrative. It becomes more important to put validity resilience, urgency and commercial harm on the record early.

The same pressure applies to defendants. Anyone hoping to use EPO momentum to slow down interim relief or the main UPC timetable will need more than the statement that an opposition is pending. The more realistic approach is to front-load the material that could actually shape the UPC’s view: the strongest novelty or inventive-step attacks, the clearest technical reasons why the patent may be unstable, and the best explanation of why those issues should matter now rather than at some later stage. Dual-track litigation no longer looks like a natural excuse for deferring part of the persuasion exercise to the EPO phase.

The EPO is no longer a passive background track

The other side of the equation matters just as much. The EPO has made clear that, once it is informed of parallel infringement or revocation proceedings before the UPC or a national court, opposition handling can move onto an accelerated track. That is not an abstract policy slogan. Reply periods can be shortened, summonses to oral proceedings can issue faster, existing hearing dates may be brought forward where possible, and written decisions and minutes are expected more quickly. The 2026 guidance continues to make that mechanism more explicit, which means court pressure at the UPC level is now being transmitted more directly into the opposition workflow.

The practical result is easy to underestimate. Some parties still think of EPO opposition as the slower forum in which technical validity points can be developed more gradually. That may no longer be safe once UPC proceedings are live. For patentees, auxiliary requests, technical explanations and fallback positions need to be prepared earlier. For opponents, the strongest prior art and invalidity theories also need to be organised sooner. On paper there are still two tracks. In practice, both sides are being pushed into a denser and earlier preparation cycle.

What businesses and advisers should change now

First, stop treating the UPC and the EPO as a neat fast-slow pair that can comfortably wait on each other. The relationship now looks more like a linked dual-clock system: the UPC is reluctant to pause, and the EPO may accelerate once it learns that court proceedings are underway. Internal case planning built around “fight in Luxembourg now, build the opposition later” or “thicken the opposition first and try to slow the UPC meanwhile” is becoming much more fragile.

Second, PI work, main-action pleadings and opposition materials should be built from a shared evidence core and prioritised earlier. Which prior art is really decisive, which expert or experimental material best supports stability, and which points belong first in the UPC rather than later at the EPO are questions that now have to be answered sooner. Third, business teams need to understand that procedural delay is no longer easy time to buy. The real source of leverage is not waiting. It is having the evidence, technical judgment and commercial risk narrative organised before the clocks on both tracks start moving at once.