T 0518/22 - Disclaimers and partial priority

Key points

• Partial priority and undisclosed disclaimers: are you ready?
• To jump to the conclusion: "Document D2 is thus prior art under Article 54(2) EPC for the subject-matter of claim 1 not enjoying priority, i.e. in relation to the "consisting" and "comprising" embodiments concerning SEQ ID NOs: 5 to 8, and prior art under Article 54(3) EPC for the subject-matter of claim 1 enjoying priority, i.e. in relation to the "consisting" and "comprising" embodiments concerning SEQ ID NO: 4."
•   The "comprising" embodiment in relation to SEQ ID NOs: 5 to 8 of claim 1 encompasses Type-A DNA polymerase mutants that are structurally identical to Taq mutants disclosed in document D2. Appellant I has not argued to the contrary. The fact that the patent does not call these polymerases Taq mutants but gives them a different name does not change the fact that these mutants are structurally identical."
• "Since the undisclosed disclaimer added to claim 1 in auxiliary request 2 (point 17 above) thus removes embodiments of document D2 which belong to the state of the art pursuant to Article 54(2) EPC and are not an accidental disclosure, such amendment is not allowable under Article 123(2) EPC. Auxiliary request 2 comprises therefore added subject-matter (G 1/03, Headnote 2.1 and G 1/16, OJ 2018, 70, Headnote)."
  
  
• On Article 13(2) RPBA: " As regards the validity of the patent's priority claim based on P the following is noted. In reply to the communication under Article 15(1) RPBA indicating the board's preliminary opinion that priority was not valid for the subject-matter of claim 1 of auxiliary request 2, appellant I has submitted for the first time the argument that embodiments of claim 1 in reference to SEQ ID NO: 4 were entitled to claim a partial priority from P. "
•  Since appellant I introduced the issue of partial priority of certain embodiments of claim 1 in response to the board's communication shortly before the oral proceedings, appellant II could not have submitted their counterarguments on this issue earlier than at the oral proceedings. The board found merit in appellant I's arguments on partial priority of claim 1 and considered it a legitimate reaction to the board's preliminary opinion. For reasons of equity, the board therefore admitted into the proceedings the new lines of arguments on partial priority of both appellants. The same applied to appellant II's new line of argument under lack of novelty over document D2 in relation thereto."
  
  
• On pre-emptively filed auxiliary requests and the need for substantiation.
• "Appellant II [The opponent] requested that auxiliary request 3 not be admitted into the proceedings, arguing in essence that appellant I did not provide any reasons in their SGA under Article 12(3) and (4) RPBA as to why this auxiliary request (filed as auxiliary request 5 with the SGA) overcame any of the objections raised. In similar circumstances these provisions had led the Boards to decide not to admit auxiliary requests, for example, in case T 559/20."
• "The board agrees with appellant I that the purpose of the amendment by deletion of all reference sequences except for SEQ ID NO: 4 in claims 1 and 9 of auxiliary request 3 was straightforward, as it was clear that it was made to establish novelty and to overcome the finding of added subject-matter. In these circumstances and differently from the situation present in the case law cited by appellant II, the level of substantiation provided in the SGA, as well as in the further submission of 14 December 2022, is considered appropriate. Further, as this amendment is occasioned by objections raised in the proceedings, it complies with the requirements of Rule 80 EPC." 
• "Furthermore the opposition division held that the patent in suit could be maintained in amended form on a request ranking higher than present auxiliary request 3 (section III above). Since appellant I was thus not negatively affected as regards auxiliary request 3, also for this reason the situation in the present case differs fundamentally from that underlying T 559/20, wherein the set of claims in suit had been the object of the appealed decision (T 559/20, Reasons 3.2). Hence, contrary to appellant II's arguments, decision T 559/20 cannot therefore support their case either."
• I think AR-3 was then filed pre-emptively with the Statement of grounds. I wonder whether the proprietor should have substantiated them in their reply to the statement of grounds of the opponent, which attacked the set of claims held allowable by the OD? Or does the pre-emptive filing liberate the proprietor from that obligation? Althoug in the present case, the amendment could have been self-evident.
• There is also some interesting reasoning on the credibility (formerly plausibility) of second medical use claims under G 2/21.
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EPO 

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

https://www.epo.org/en/boards-of-appeal/decisions/t220518eu1