T 0217/23 - The duty of the proprietor in opposition proceedings

Key points

• The proprietor, as respondent, files auxiliary requests in appeal. The Board finds the proprietor's main request (claims held allowable by the OD) to be not allowable. 
•  "At issue is whether a patent proprietor may wait for the preliminary opinion of the opposition division to react to the objections raised in the notice of opposition and whether, where the preliminary opinion is positive, no auxiliary claim requests with fallback positions need to be filed, unless the opposition division changes its opinion at oral proceedings."
• "In inter partes proceedings, each party has to be given equal opportunity to present its case and a fair chance to respond to new matter raised by the other party or parties, or by the opposition division. The opposition division and the parties have to observe the principle of good faith (T 669/90, OJ EPO 1992, 739, points 2.3 and 2.4; T 201/92, point 3.5). To expedite the proceedings and implement the principle of fairness towards the other party or parties, each party must submit all facts, evidence, arguments and requests for amendments relevant for its case as early and completely as possible, and not in a piecemeal manner (T 326/87, OJ EPO 1992, 522, points 2.1.1 and 2.1.2; T 430/89, point 5.3; T 951/91, OJ EPO 1995, 202, points 5.2 and 5.3). This case law developed mainly in the context of Article 114(2) EPC pertaining to facts and evidence. 
• Nevertheless, in view of the principles set out above, the rationale of this case law also applies to a patent proprietor's observations and amendments (Rule 79(1) EPC), which should not only include all facts and evidence relied on to defend the patent (T 502/98, point 1.5) but also requests for amendment of the patent considered necessary to address the main objections raised by the opponent in case these should be found to prejudice the maintenance of the patent (see e.g. T 582/08, point 8.5)."
• "Patent proprietors do not have a privileged position in opposition proceedings allowing them to address objections raised by opponents by way of requests for amendment only when presented with the preliminary or final opinion of the opposition division in the summons or during oral proceedings."
• "This would be unfair to the opponents as they would be confronted at a very late stage with a change in the object of the proceedings that they could not reasonably have foreseen and for which they could not prepare. To expect a patent proprietor to address in its observations to a notice of opposition the objections raised by the opponents also by filing suitable fallback positions does not place an undue burden on the patent proprietor. "
• A proper response to an opposition does not require permutations of sets of amended claims that address each objection individually or in any combination as this would leave it to the opposition division to identify any patentable subject-matter from such a plethora of claim sets and unduly burden the proceedings.
• It seems common practice in appeal proceedings.
• "Presented with an opponent's complete case at the outset of the opposition proceedings, a patent proprietor, knowing its commercial interests, should be able to define a reasonable number of fallback positions that address the main issues in its observations to the opposition. Although the persuasiveness of objections by opponents cannot be predicted with absolute certainty, the duty to file requests for amendment cannot solely depend on the opinion by the opposition division as this would imply a shift of the patent proprietor's responsibility for making its case to the opposition division and would compromise the opposition division's duty to equal treatment of the parties. "
• "Of course, there are complex cases in which numerous objections are raised which cannot be fully addressed by a reasonable number of requests for amendments and which might even require the patent proprietor to adopt non-convergent strategies of defence to safeguard its commercial interests in a patent. Nevertheless, also in these cases, the main lines of defence should emerge from the patent proprietor's observations to an opposition which also must include any request for amendment to give the opponent a proper opportunity to reply to new matter and to avoid ping-pong submissions immediately before or during oral proceedings before the opposition division."
• Requiring the submission of all facts, evidence, arguments and requests for amendments relevant for the patent proprietor's case as early and completely as possible does not preclude further submissions, including the filing of additional requests for amendment in the course of opposition proceedings if there are good reasons, for example, responding to new evidence, addressing new objections or dealing with unforeseen challenges relating to gaps in the chain of evidence or argument which emerge during the course of the proceedings.
• So far, the Board could be setting a framework for the OD to decide on the admissibility of auxiliary requests filed after the proprietors' first reply to the opposition, in particular on the admissibility of auxiliary requests filed by the Rule 116 date.
• However, the Board provides the above reasons as part of the reasoning to hold auxiliary requests inadmissible that were filed by the respondent with the reply to the appeal. In particular, the OD had decided to maintain the patent in amended form, and in the ARs the claims are narrowed compared to the claims held allowable by the OD. [edit 08.10.2025]
• Hence, the OD would not have even considered the auxiliary requests at issue and whether they were filed or not would not make a difference for the judicial review of the OD's decision, it seems. In other words, had the ARs been filed already before the OD (timely), they would have been carry-over requests that had not been considered in the written decision of the OD, but then would have been admissible under Art. 12(4) RPBA.

EPO 

The link to the decision can be found after the jump.

https://www.epo.org/en/boards-of-appeal/decisions/t230217eu1