Compliance with this principle is not optional. The consequences of inadequate preparation are severe: late-filed evidence, new grounds of invalidity, and supplementary arguments may all be excluded from proceedings, regardless of their potential merit. The Court has demonstrated a consistent willingness to exercise its discretion to disregard submissions that could and should have been filed earlier, leaving parties without recourse to arguments they had hoped to deploy.

This edition of UPChronicle examines the front-loaded principle in detail: its foundations, the specific pleading requirements it imposes, and the difficulties that arise when parties attempt to introduce evidence or arguments at later stages.

What is the front-loaded principle? 

The UPC’s procedural system is expressly designed to be “front-loaded” meaning parties must set out their full case as early as possible. This foundational principle is enshrined in Paragraph 7 of the Preamble to the RoP, which states that parties “shall cooperate with the Court and set out their full case as early as possible in the proceedings”.

The proceedings are designed so that a final oral hearing on infringement and validity at first instance can normally take place within one year. 

Rule 13(1) RoP, which sets out the mandatory contents of the Statement of Claim is an indication of the UPC’s intention to conduct “front-loaded” litigation where all the information necessary for the defendant’s assessment of the allegations shall be included in the pleadings. The rationale behind these provisions is first to ensure that the defendant is aware of the factual elements and grounds upon which the claim against it is based, as well as the evidence available to the claimant, thereby enabling them to prepare an adequate defence. And second, to expedite the proceedings. As the Central Division in Paris has explained, these objectives “would be undermined if the claimant were permitted to gradually introduce new factual circumstances, new legal arguments, or new evidence into the proceedings” (Meril v Edwards).

The Court of Appeal confirmed that the front-loaded nature of UPC proceedings, including the possibility to disregard late-filed arguments and evidence, also applies to proceedings for provisional measures, “albeit that the short time periods for filing a response, reply or rejoinder may allow for a more lenient approach.” (Angelalign v Align).

The consequences of this approach have been recognised to extend to cost allocations: because UPC proceedings are front-loaded “most of the expenses for Defendants is to prepare the Statement of Defence and (possible) Counterclaim for Revocation” meaning that significant costs are incurred at the very outset of proceedings (CooperSurgical).

Pleading requirements

What does the front-loading principle mean for specific pleadings?

Statement of Claim

The RoP set out a comprehensive and mandatory list of information that the Statement of Claim must contain under Rule 13(1). This includes:

• The names and addresses of the parties and their representatives.
• Details of the patent concerned, including any prior or pending proceedings.
• An indication of the division which should hear the action with an explanation of competence.
• An indication of the facts relied on, including specific instances of alleged infringement with date and place, and the patent claims alleged to be infringed.
• The evidence relied on, where available, and an indication of any further evidence to be offered.
• The reasons why the facts relied on constitute infringement, including arguments of law and, where appropriate, an explanation of the proposed claim interpretation.
• A list of documents referred to, including witness statements, together with copies.

Statement of Defence

The Statement of Defence must be lodged within three months of service of the Statement of Claim (Rule 23 RoP). It must contain: an indication of the facts relied on (including any challenge to the claimant’s facts); the evidence relied on; the reasons why the action should fail (including arguments of law and any challenge to the claimant’s proposed claim interpretation); and, where applicable, a Counterclaim for Revocation.

Revocation Actions and Counterclaims

The Statement for Revocation (or Counterclaim for Revocation) must similarly contain an indication of the grounds for revocation supported by arguments of law, the facts relied on, and the evidence relied on (Rules 44 and 25 RoP, Meril v Edwards, and Messerle v Sabert). As the Court has emphasised, the party “is obliged to submit its arguments, facts and attachments in its Counterclaim of Revocation. Submitting evidence for prior state of the art (or for prior use) at a later time requires a reasonable justification regarding to the timeliness” (Messerle).

Reply and Rejoinder

The Reply and Rejoinder are further constrained in scope. The Rejoinder “shall be limited to a response to the matters raised in the Reply” (Rule 52 RoP). This limitation is central to the front-loaded system: parties cannot use later pleadings to introduce entirely new lines of argument or grounds of invalidity that should have been raised at the outset.

Difficulties with late-filed evidence and arguments

New grounds of invalidity

Case law has firmly established that new grounds of invalidity cannot be introduced after the first written submission. The Central Division has held, consistently with UPC-wide case law, that “new grounds of invalidity of the attacked patent cannot be introduced after lodging the first written submission of the written procedure” (Meril v Edwards). This is because the initial Statement for Revocation defines the subject matter of the dispute, and introducing new lines of attack constitutes “an amendment of the case” falling within Rule 263 RoP. For example, in Meril v Edwards, a new added-matter argument raised only in the Reply was excluded because it should have been filed with the Statement for Revocation pursuant to Rule 44.

Adding new infringement claims

Adding new infringement claims after serving the Statement of Claim is procedurally difficult. In Ona v Google, Ona sought to introduce indirect infringement claims later in the proceedings. The request was rejected by the judge-rapporteur and then by the full panel. Ona argued that direct infringement had already been raised and concerned the same Google devices, but the amendments were rejected because of the front-loaded procedure and the need to allow the defendant to respond properly. The UPC also noted that Ona failed to justify the late filing, especially since Google had highlighted in its Statement of Defence that no indirect infringement claim had been made.

Late-filed evidence and documents

New evidence submitted with later pleadings faces scrutiny. The Court will admit new documents only where they are “considered capable of supporting the main facts already timely alleged and disputed by the defendant” and are responsive to the opposing party’s arguments.

In Meril v Edwards, expert opinions and academic papers filed with the Reply were admitted because they were “intended to contrast and react to the arguments raised by defendant in its defence to revocation”. Conversely, in Messerle v Sabert, new prior art evidence filed in a Reply was disregarded because it “does not further develop the point in dispute… but opens up a new point, namely a new novelty attack”. The Court considered it “possible and reasonable that the Defendant could have submitted the arguments, facts and attachments in its counterclaim of revocation” within the applicable deadline.

Subsequent patent amendments (auxiliary requests)

Rule 30.2 RoP provides that any subsequent request to amend the patent (beyond the initial Application to Amend) may only be admitted with the Court’s permission and on an exceptional basis (Fisher & Paykel v Flexicare). This has been described as a “strict preclusion rule”: “the patentee shall introduce all the amendments with the application to amend the patent. Only in exceptional circumstances shall a subsequent amendment be allowed” (Fisher & Paykel v Flexicare).

In Fisher & Paykel v Flexicare, subsequent auxiliary requests (2A to 13A) were rejected. The defendant argued they were responsive to new clarity objections, but the Court held that the defendant “should have and could have foreseen the claimant’s clarity objection”. The Court stressed that even where the other party and the Court might have enough time to consider subsequent amendments before an oral hearing, that alone is “not sufficient reason for allowing subsequent amendments”.

Amendments to claims under Rule 263 RoP

Where a party seeks to change its claim or amend its case, Rule 263 RoP requires the party to demonstrate that: the amendment could not have been made with reasonable diligence at an earlier stage; and the amendment will not unreasonably hinder the other party in conducting its action. In Canon v Katun, an amendment extending the scope was permitted because the relevant case law (Kaldewei v Bette) had not yet been issued when the Statement of Claim was filed, and the defendants had had the opportunity to respond in their Rejoinder.

Admitted exceptions: responsive arguments

Not all late submissions are rejected. The Court of Appeal has established that “while the parties are required to set out their case as early as possible in the proceedings, nevertheless specific new arguments may be admitted into the proceedings in consideration of specific circumstances of the case” (Meril v Edwards). A “generous standard” is to be applied when assessing whether an argument is newly introduced or merely a reaction to previously filed arguments (Meril v Edwards). Arguments in a Rejoinder that respond to matters raised in the Reply are permissible under Rule 52 RoP. Likewise, the principle of fairness may require that a claimant in revocation proceedings be allowed to introduce new facts and evidence in response to the Statement of Defence—including evidence to prove a point already made on common general knowledge or to rebut evidence brought forward by the defendant (VMR v NJOY).

Further Written Pleadings

The judge-rapporteur may, on a reasoned request, allow the exchange of further written pleadings under Rule 36 RoP.

However, this power is exercised cautiously: in Sanofi-Aventis v Amgen, the judge-rapporteur allowed a short additional pleading addressing new points raised in expert declarations accompanying the Rejoinder, but only because the submission was limited to a small number of new points and was relatively short. Attempts to introduce entirely new infringing products or new substantive arguments through a Rule 9 RoP application have been refused, particularly where the defendant would not have had sufficient opportunity to respond.

For appeals, the Court of Appeal confirmed that further exchanges are permitted only where “required by the principles of due process, such as in particular the principles of fairness, equity and efficiency and the right to be heard” (Hurom v NUC Electronics).

Conclusion

In summary, the UPC system places a premium on thorough preparation before proceedings are initiated. Parties must present their complete case from the very first pleading. Whilst the Court retains discretion to admit responsive material and accommodate genuinely unforeseen developments, the overarching expectation is that each party’s case is essentially complete by the close of the written procedure, and late filings that could have been made earlier with reasonable diligence will very frequently be excluded.