Overview of notification and time-limit calculation rules before and after 1 November 2023

Today, amended Rules 126(2)/127(2)/131(2) EPC entered into force, abandoning the 10-day legal fiction for deemed notification as applicable for time limits triggered by a notification, and replacing it by the date of dispatch and a compensation for late receipt (similar as in PCT Rule 80.6).

See:

• OJ 2022, A101 Decision of the Administrative Council of 13 October 2022 amending Rules 46, 49, 50, 57, 65, 82, 126, 127 and 131 of the Implementing Regulations to the European Patent Convention (CA/D 10/22), article 1.10-12, art 2 second sentence and art 3 second sentence
• OJ 2022, A114 Notice from the European Patent Office dated 25 November 2022 concerning legal changes to support digital transformation in the patent grant procedure, section IV.
• OJ 2023, A29 Notice from the European Patent Office dated 6 March 2023 concerning amended Rules 126, 127 and 131 EPC

OJ 2023, A29 provides:

 II. Fiction of notification on the date of the document

Amended Rules 126(2) and 127(2) EPC introduce a new notification fiction, according to which postal and electronic notification are deemed to occur on the date of the document. As a result, the current notification fiction by which a document is deemed to be delivered to the addressee on the tenth day following its handover to the postal services or on the tenth day following its transmission by means of electronic communication ("ten-day rule") will be abandoned from 1 November 2023.

According to established EPO practice, the date of the document is the date on which it is handed over to a postal service provider in the case of postal notification or the date of its electronic transmission to the Mailbox in the case of electronic notification. To ensure this, the EPO post-dates its documents to allow them to be processed internally and issued on the date they bear. The EPO also has a reliable system for tracking documents dispatched using postal services or transmitted electronically via the Mailbox.

In the case of postal notification under Rule 126(2) EPC, the relevant date for the purpose of applying the notification fiction is the date printed on a document, e.g. a communication from the EPO, and not any other date possibly stamped on the envelope carrying that document by a postal service provider. To reflect this, the word "letter" has been replaced with the word "document" in the first sentence of amended Rule 126(2) EPC.

As is the case today, electronic notification under Rule 127(2) EPC will not occur before the date of the document. Accordingly, even if the addressee can access the document via the Mailbox before this date, the decisive date for the purpose of the notification fiction under Rule 127(2) EPC is the date of the document.

 [...] 

IV. Calculation of periods in proceedings before the EPO

The notification fiction provided for in Rules 126(2) and 127(2) EPC is relevant in the context of time-limit calculation under Rule 131(2) EPC. Since these provisions are intrinsically linked, some clarification has been provided in Rule 131(2) EPC to take better account of the revised notification fiction.

Under amended Rule 131(2) EPC, in the case of notification, it is the deemed receipt of the document notified that will constitute the relevant event for the purpose of time-limit calculation. As a result, periods triggered by notification will start running from the deemed receipt of a document, i.e. the date of the document under Rules 126(2) and 127(2) EPC.

As the EPO will continue to apply a notification fiction, as is the case today, it will be relieved from establishing the actual date of receipt of each document for the purpose of Rule 131(2) EPC, apart from in exceptional cases of dispute.

V. Entry into force and transitional provision

The amendments to Rules 126(2), 127(2) and 131(2) EPC will enter into force on 1 November 2023. They will apply to documents notified by postal services or electronic means on or after this date. Since the issuing of a document is the event triggering the notification process, the decisive date for determining whether the revised notification and time-limit calculation rules apply to a specific document notified is the date of that document. Examples 2 and 3 of OJ 2023, A29 illustrate the application of this transitional provision.

Annexes

A) Amended Rules 126(2), 127(2) and 131(2) EPC as in force as of 1/11/2023

Amended Rule 126(2) EPC as in force as of 1/11/2023:

(2) Where notification is effected in accordance with paragraph 1, the document shall be deemed to be delivered to the addressee on the date it bears, unless it has failed to reach the addressee. In the event of any dispute concerning the delivery of the document, it shall be incumbent on the European Patent Office to establish that the document has reached its destination and to establish the date on which the document was delivered to the addressee. If the European Patent Office establishes that the document was delivered to the addressee more than seven days after the date it bears, a period for which the deemed receipt of that document is the relevant event under Rule 131, paragraph 2, shall expire later by the number of days by which the seven days were exceeded.

Amended Rule 127(2) EPC as in force as of 1/11/2023:

(2) Where notification is effected by means of electronic communication, the electronic document shall be deemed to be delivered to the addressee on the date it bears, unless it has failed to reach its destination. In the event of any dispute concerning the delivery of the electronic document, it shall be incumbent on the European Patent Office to establish that the document has reached its destination and to establish the date on which it reached its destination. If the European Patent Office establishes that the electronic document has reached its destination more than seven days after the date it bears, a period for which the deemed receipt of that document is the relevant event under Rule 131, paragraph 2, shall expire later by the number of days by which the seven days were exceeded.

Amended Rule 131(2) EPC as in force as of 1/11/2023:

(2) Computation shall start on the day following the day on which the relevant event occurred, the event being either a procedural step or the expiry of another period. Where the procedural step is a notification, the relevant event shall be the deemed receipt of the document notified, unless otherwise provided.

B) Rules 126(2), 127(2) and 131(2) EPC as in force until and on 31/10/2023

For documents send before today, the previous versions of the rules continue to apply:

Rule 126(2) EPC as in force until and on 31/10/2023:

(2) Where notification is effected in accordance with paragraph 1, the letter shall be deemed to be delivered to the addressee on the tenth day following its handover to the postal service provider, unless it has failed to reach the addressee or has reached him at a later date; in the event of any dispute, it shall be incumbent on the European Patent Office to establish that the letter has reached its destination or to establish the date on which the letter was delivered to the addressee, as the case may be.

Rule 127(2) EPC as in force until and on 31/10/2023:

(2) Where notification is effected by means of electronic communication, the electronic document shall be deemed to be delivered to the addressee on the tenth day following its transmission, unless it has failed to reach its destination or has reached its destination at a later date; in the event of any dispute, it shall be incumbent on the European Patent Office to establish that the electronic document has reached its destination or to establish the date on which it reached its destination, as the case may be. 

Rule 131(2) EPC as in force until and on 31/10/2023:

(2) Computation shall start on the day following the day on which the relevant event occurred, the event being either a procedural step or the expiry of another period. Where the procedural step is a notification, the relevant event shall be the receipt of the document notified, unless otherwise provided. 

"I. The European Patent Office is competent to assess whether a party is entitled to claim priority under Article 87(1) EPC. There is a rebuttable presumption under the autonomous law of the EPC that the applicant claiming priority in accordance with Article 88(1) EPC and the corresponding Implementing Regulations is entitled to claim priority." 
"II. The rebuttable presumption also applies in situations where the European patent application derives from a PCT application and/or where the priority applicant(s) are not identical with the subsequent applicant(s). In a situation where a PCT application is jointly filed by parties A and B, (i) designating party A for one or more designated States and party B for one or more other designated States, and (ii) claiming priority from an earlier patent application designating party A as the applicant, the joint filing implies an agreement between parties A and B allowing party B to rely on the priority, unless there are substantial factual indications to the contrary."

Summary of Facts and Submissions

5. Articles 87 to 89 EPC form Chapter II (titled "Priority") of Part III of the EPC. They provide a complete, self-contained code of rules of law on the subject of claiming priority for the purpose of filing a European patent application (G 1/15, OJ EPO 2017, A82, Reasons, point 5.2.3; J 15/80, OJ EPO 1981, 213, Headnote I). Since the EPC constitutes, according to its preamble, a special agreement within the meaning of Article 19 of the Paris Convention for the Protection of Industrial Property ("Paris Convention"), the EPC provisions on priority are intended not to contravene the basic principles concerning priority of the Paris Convention (see G 3/93, OJ EPO 1995, 18, Reasons, point 4; G 2/98, OJ EPO 2001, 413, Reasons, point 3).

26. Article 87 as well as Articles 88(2), (3) and (4) EPC pertain to the material conditions under which priority rights may be derived from an earlier application. Article 88(1) EPC concerns the procedural requirements to be met by an applicant desiring to take advantage of the priority of an earlier application, namely the filing of a declaration of priority and other documents with the EPO. These procedural requirements are further specified in the Implementing Regulations (Rules 52 to 54 EPC). Article 89 EPC prescribes the effect of a priority right, i.e. that the priority date shall count as the date of filing of the European patent application for the purposes of the delimitation of the prior art under Articles 54(2) and (3) EPC. In other words, the priority right allows the exclusion of everything that has become prior art between the priority date and the filing date (often referred to as "intermediate prior art") for the assessment of patentability.

27. Article 87(1) EPC provides that "[a]ny person who has duly filed, in or for (a) any State party to the Paris Convention for the Protection of Industrial Property or (b) any Member of the World Trade Organisation, an application for a patent, a utility model or a utility certificate, or his successor in title, shall enjoy, for the purpose of filing a European patent application in respect of the same invention, a right of priority during a period of twelve months from the date of filing of the first application" (emphasis added). Article 87(1) was amended in the context of EPC 2000, inter alia, by the introduction of the reference to applications filed in a Member of the World Trade Organisation in order to align the provision with the TRIPS Agreement (bullet point (b) in Article 87(1) EPC, see OJ EPO Special Edition 4/2007, p. 88).

28. The "same invention" criterion of Article 87(1) EPC (often referred to as "substantive priority" or "substantive validity of the priority") is regularly an issue in examination and opposition proceedings, and it was underlying two referrals to the Enlarged Board: G 2/98 (OJ EPO 2001, 413) and G 1/15 (OJ EPO 2017, A82). The present referral concerns the question whether the applicant of the later application is entitled to claim the priority of the earlier application, in particular as a successor of the applicant of the priority application (often referred to as "formal priority" or formal validity of the priority; for the terminology see e.g. the comments of the President of the EPO of 8 July 2022, footnote 1).

29. Hereafter, to maintain consistency with the referring decision and existing case law (e.g. T 844/18), the application from which priority is claimed ("first application" in Article 87(1) EPC, "previous application" in Article 88(1) EPC) shall be referred to as the "priority application". Any application claiming priority from a priority application shall be referred to as a "subsequent application". Accordingly, the respective applicant shall be the "subsequent applicant" and the applicant of the priority application the "priority applicant".

30. Article 4A(1) Paris Convention provides: "Any person who has duly filed an application for a patent, or for the registration of a utility model, or of an industrial design, or of a trademark, in one of the countries of the Union, or his successor in title, shall enjoy, for the purpose of filing in the other countries, a right of priority during the periods hereinafter fixed." (emphasis added) The extension of the priority entitlement to the successor in title (i.e. the second underlined passage in the quote above) was introduced at the Washington Conference in 1911 (Bodenhausen, Paris Convention for the Protection of Industrial Property, Geneva 1968, p. 37). With respect to the definition of the parties entitled to claim priority from an earlier patent application ("any person who has duly filed an application (...) or his successor in title"), the provisions of Article 4A(1) Paris Convention and of Article 87(1) EPC are identical.

Interpretation and scope of the referred questions

Question I

31. Question I ("Does the EPC confer jurisdiction on the EPO to determine whether a party validly claims to be a successor in title as referred to in Article 87(1)(b) EPC?") refers to Article 87(1)(b) EPC only, where reference is made to priority filings in or for Members of the World Trade Organisation. Article 87(1)(a) EPC refers to priority filings in or for States party to the Paris Convention. The "successor in title" passage in Article 87(1) EPC is not specific to one of the groups of states referred to in Article 87(1)(a) and (b) EPC. These groups overlap to a large extent, and the legal issues are the same for both groups. Moreover, question II refers to "claiming priority rights under Article 87(1) EPC". It is therefore assumed that the reference to sub-paragraph (b) of Article 87(1) EPC in question I is of no relevance.

32. The wording of question I with respect to the jurisdiction of the EPO is clear in that it addresses the competence of the EPO (i.e. of the examining and opposition divisions and also the boards of appeal) to assess the entitlement to claim priority of the party filing the subsequent application.

33. There may be uncertainties about the entitlement to claim priority under Article 87(1) EPC also in cases where not the succession in title but the identity of the person having filed the priority application is in dispute. In T 844/18, concerning a situation where four inventors were applicants of the priority application and only three of them filed the subsequent European application and claimed priority, the board took the position that succession in title was not an issue in this case (see Reasons, point 21). In the Reasons (point 9 and 23) of T 844/18, reference is made to the jurisdiction to examine "who is entitled to the right of priority" (Reasons, points 9 and 23). The discussion of the EPO's jurisdiction in T 844/18 consequently encompasses the determination of both the person who filed the priority application and its successor in title. Similar to the facts underlying T 844/18, a legal entity consisting of a plurality of persons or entities (such as a partnership) may be the applicant of a priority application, and the same entity with a changed composition or membership may claim priority from this application. In such situations, it may be difficult to distinguish between the determination of the personal identity between the two applicant entities and the assessment of a succession in title.

34. To cover all situations where the right of an applicant to claim priority is relevant in proceedings before the EPO, question I is rephrased as follows: "Is the EPO competent to assess whether a party is entitled to claim priority under Article 87(1) EPC?". As explained in the communication of the Enlarged Board of 21 March 2023, question I refers to the EPO's competence to assess the entitlement to claim priority for the subsequent application and it encompasses all situations where the applicant claiming priority for its subsequent application is not clearly identical with the applicant of the priority application.

35. As has long been pointed out in the discussions on entitlement to priority, the issue of entitlement not only arises with respect to a patent or patent application examined or opposed to in proceedings before the EPO. The issue equally arises with respect to prior art, namely patent documents forming prior art under Article 54(3) EPC and relying on a priority date prior to the effective date of the European patent application or European patent under consideration (see e.g. T 493/06, Reasons, points 1 to 11; T 382/07, Reasons, point 9). Question I is understood to cover both cases; the objection that an applicant was not entitled to claim priority can equally be raised by an opponent (if the priority issue concerns the opposed patent) or by a patent proprietor (if the priority issue concerns a prior art document).

Question II

36. Question II is understood to concern proceedings before any instance or department of the EPO where the situation described in question II occurs. According to the referring decision, the question needs to be answered only "[i]f question I is answered in the affirmative".

37. The question covers a special situation occurring where a party, typically the inventor(s), files a US priority application (also in the form of a provisional application) which is then used as priority application for a later PCT application designating one party (typically still the inventor(s)) for the US only and another party (typically the employer of the inventor(s)) for regional European patent protection. Before the "America Invents Act" (AIA) of 2011 entered into force, only the inventor(s) could be applicants in a US patent application (see e.g. Druschel/Kommer, Die formelle Priorität europäischer Patente, GRUR 2022, 353). The priority application underlying the present referral (filed in 2004) had to be filed by the inventors under the then applying laws.

38. As implied by the referring decision (see Reasons, point 43), the wording of question II is addressing the facts underlying the referral and the "PCT joint applicants approach" (see above point 11) in a general way but it is not to be understood as being further limited to specific factual circumstances (e.g. to a number of parties).

39. As pointed out in the referring decision (Reasons, point 18), confusion should be avoided between the "PCT joint applicants approach" mentioned above and the "all applicants approach" used, for example, in decision T 844/18 (Facts and Submissions, point VIII). In this case, four inventors were applicants of the priority application and only three of them filed the subsequent PCT application (encompassing the European application) and claimed priority. The priority claim failed to meet the requirement that all applicants of the priority application must also be applicants of the subsequent PCT application for which the priority is claimed.

40. The referring decision critically summarises various possible legal bases for the "PCT joint applicants approach" (Reasons, points 28 to 39). However, the referring board did not limit its question II to the viability of the "PCT joint applicants approach", thereby leaving open the possibility that question II could be answered in the affirmative with another reasoning (for example, by acknowledging that the joint filing of a PCT application is sufficient proof for the validity of the priority claim).

41. As far as the reference to Article 4 of the Paris Convention at the end of question II is concerned, it is understood that this refers to compliance with all provisions of Article 4 Paris Convention except for the entitlement to priority as addressed in Article 4A(1) Paris Convention (see above point 30).

42. The referring decision addresses the conflict of laws rules applicable to the transfer of priority rights, noting that a separate question was not necessary "because it is inherently contained in the questions posed and it will be addressed in the considerations of the EBA, as needed" (Reasons, point 37).

Admissibility of the referral

Requirements for admissibility

43. According to Article 112(1)(a) EPC, "[i]n order to ensure uniform application of the law, or if a point of law of fundamental importance arises", a board of appeal "shall, during proceedings on a case and either of its own motion or following a request from a party to the appeal, refer any question to the Enlarged Board of Appeal if it considers that a decision is required for the above purposes."

44. The Enlarged Board must examine the above admissibility requirements with respect to each referred question individually (G 1/19, OJ EPO 2021, A77, Reasons, point 56, with further references).

Question I - Jurisdiction of the EPO

45. Since the Enlarged Board takes the position that question II should be admitted (see below points 49 ff), question I should also be admitted for the sole reason that the questions are interlinked insofar as an affirmative answer to question I is a precondition for approaching question II. However, question I in itself already fulfils the requirement of Article 112(1) EPC that an answer is required to ensure uniform application of the law or because a point of law of fundamental importance arises.

46. The issue of entitlement to priority arises with every patent application for which priority from an earlier application is claimed or which is confronted with prior art patent documents claiming priority. Where priority entitlement is disputed in any proceedings, the EPO instance addressing the issue must (at least implicitly) decide on question I. The question - or an affirmative answer thereto - thus can be viewed as fundamental for any investigation of priority entitlement under Article 87(1) EPC. The discussion concerning question I in the present referral proceedings shows that fundamental questions of law are touched upon, such as the extent of the EPO's jurisdiction for questions of civil law or the right of a third party to challenge entitlement to priority rights to which the third party cannot claim any entitlement.

47. It has been argued in certain amicus curiae briefs (Vossius & Partner and Grund IP Group) that question I should not be admitted because there was no conflicting case law on the issue of the EPO's jurisdiction. However, diverging decisions are not a requirement for the admissibility of a referral if a board is referring a question to the Enlarged Board (Article 112(1)(a) EPC). Regardless of whether or not any decisions are in direct conflict with e.g. T 844/18, the EPO's jurisdiction concerning the entitlement to the priority right has been questioned by boards of appeal in several cases (see the referring decision, Reasons, point 26), and the issue is arising in various other cases before different boards. The condition that an answer of the EPO is required to ensure uniform application of the law is therefore met.

48. The Enlarged Board is satisfied that both of the alternative conditions of Article 112(1)(a) EPC are met (point of law of fundamental importance and necessity to ensure uniform application of the law). The condition that an answer to question 1 is needed for the referring board to decide is met because an answer is needed to question II (above point 45). For these reasons, referred question I is admissible.

Question II - Validity of the priority in the specific case

49. Question II mirrors the facts underlying the referring decision (see above point 38). An answer to question II is therefore required for the referring board to decide in the two pending appeal cases.

50. As described above (point 37), question II concerns a specific situation related to US law where only inventor(s) could file a patent application. This requirement has ceased to exist. However, apart from the two cases underlying this referral, there are still a significant number of cases pending where the application was filed while only inventors could apply for a US patent (see e.g. case T 419/16, where an interlocutory decision was taken on 3 February 2022 to stay the appeal proceedings until a decision is issued in the present referral). Moreover, inventors still act as applicants for the US only in cases where the PCT application is filed both for the US and for protection in Europe under the EPC.

51. While the question refers to a specific situation, the answer would not necessarily be limited to the viability of the "PCT joint applicants approach" and it may cover other situations where the applicant's entitlement to the priority right is challenged. However, even if the answer covered only the situations described in question II, the question is considered to touch a point of law of fundamental importance in the terms of Article 112(1) EPC.

52. The Enlarged Board is not aware of any case law challenging the viability of the "PCT joint applicants approach". However, it is noted that the possible legal bases for this concept have been questioned even in the referring decision (Reasons, points 28 to 33). The fact that there are different legal bases proposed for the "PCT joint applicants" approach already shows that there is no uniform approach to this concept. Moreover, decisions of national courts (see Reasons of the referring decision, points 40 and 41) and various amicus curiae briefs base their positions supporting an applicant's right to priority on other arguments than the "PCT joint applicants approach" (see above point 24). In view of future case law, it is desirable that not only the answer to question II is uniform but also the basic reasoning behind such answer.

53. Since an answer to question II is necessary for the referring board to decide the pending appeal cases and at least the criterion of "a point of law of fundamental importance" under Article 112(1)(a) is met, question II is admissible.

The "right of priority" and its assignment under Article 87 EPC

Purpose of priority rights

54. The basic purpose of the right of priority is to safeguard, for a limited period, the interests of patent applicants in their endeavour to obtain international protection for their inventions, thereby alleviating the negative consequences of the principle of territoriality in patent law (T 15/01, OJ EPO 2006, 153, Reasons, point 32, with references to the relevant literature). The priority provisions contained in the Paris Convention should not be regarded as a body of exception clauses which should be interpreted strictly (see in this respect T 998/99, OJ EPO 2005, 229, Reasons, point 3.1; see also T 1201/14, Reasons, point 3.2.1.3). To the contrary, the Rules of the Paris Convention and the self-contained priority system of the EPC should be construed in a manner which ensures that the above-mentioned general purpose is fulfilled as far as possible (T 15/01, Reasons, point 34, confirmed in T 5/05, Reasons, point 4.4; see also Straus, The Right to Priority in Article 4A(1) of the Paris Convention and Article 87(1) of the European Patent Convention, JIPLP 2019, 687, 688/689).

55. For the person filing a patent application in a state addressed in Article 87(1) EPC, the priority system means that it has the option to file a bundle of subsequent applications for the same invention in a freely selected group of other territories where each of the later (national or regional) applications may benefit from the priority date of the first application. The priority period of twelve months on the one hand allows for an evaluation by the applicant as to where patent protection should be sought. On the other hand, the clear limitation of the period provides legal certainty to third parties who ought to know the geographical limitations of the patent protection they may be confronted with.

56. The effect of the priority right (namely, the exclusion of intermediate prior art; see above point 26) often concerns publications originating from the priority applicant or persons connected with it. The priority right thus also protects an applicant from its own intermediate prior art and allows it to publish the content of the priority application before the subsequent applications are filed. This aspect is of particular relevance in a patent system like the European patent system that generally does not provide grace periods prior to filing a patent application during which publications of the applicant are non-prejudicial.

57. Only the subsequent application (for which priority is claimed) and the respective applicant may benefit from the priority right. For the priority application, the priority right derived therefrom is irrelevant since for the priority application there is no period between the priority date and the application date (and, consequently, no intermediate prior art).

EPO case law under Article 87 EPC

Jurisdiction of the EPO

58. In most of the cases where the boards had to assess whether the applicant of a subsequent application was entitled to claim priority under Article 87(1) EPC, the boards tacitly assumed that they had jurisdiction for such assessment. In T 844/18, where this jurisdiction was challenged, the board affirmed its jurisdiction, primarily because it saw no reason why it should concern itself with three of the requirements for priority under Article 87(1) EPC (where? / what? / when?) but not with the first requirement (who?) (see Reasons, points 11 to 14). The board also did not see a possibility for applying Article 60(3) EPC (i.e. the presumption that the applicant is entitled to exercise the right to a European patent) by analogy to the right to claim priority under Article 87(1) EPC (Reasons, point 15). These views in T 844/18 were confirmed in T 2431/17, see Reasons, point 1.5.2).

59. However, deviating positions have been discussed within the boards of appeal, as shown in the non-binding preliminary view of the board in the communication of 14 June 2017 in case T 239/16. (The priority issue was not relevant for the final decision.) There is more widespread scepticism concerning the EPO's jurisdiction for determining entitlement to priority. This has also been demonstrated by the positions taken in the amicus curiae briefs and by the different positions taken by the two opponents in the inter partes case underlying this referral (see above point 22).

60. From the case law quoted by the different stakeholders, the conclusion could be drawn that before T 62/05 and T 788/05, the entitlement to priority was not regularly questioned, which would mean that the EPO's jurisdiction in this respect was not an issue in most cases. Earlier decisions quoted in this context (most notably T 1008/96) appear to be isolated cases. Another early decision, J 11/95 is even quoted as a counterexample since it held that the EPO had no jurisdiction to decide claims to the right to national patent applications or priority rights derived therefrom (Reasons, point 4). In an amicus curiae brief (efpia) it was noted that attacks on formal priority started to become routine in EPO oppositions from about 2010, and it was speculated that such objections became popular after practitioners became alerted through some decisions of national courts in the United Kingdom and because they offered a simple way to invalidate patents whenever there was intervening prior art. In response to a question in the Enlarged Board's communication of 21 March 2023, respondent I provided, in its letter of 5 May 2023, statistical evidence supporting the assertion that there has been a "dramatic increase in frequency" of priority entitlement challenges from 2015 onwards.

61. Considering the rarity of priority entitlement challenges during the first decades of the EPO, it can be concluded that the boards' case law is substantially uniform (at least during the past 10 or 15 years) insofar as the EPO is viewed to have jurisdiction to decide who is entitled to claim priority. When it comes to how the EPO should decide disputes on entitlement to priority, the case law is diverging or has not developed much in many aspects.

Application of national law to assess succession under Article 87(1)EPC

62. According to consistent case law, national law is applicable to the succession in title addressed in Article 87(1) EPC (see e.g. T 1201/14, Reasons, point 3.1.2, with further references). The EPC contains no conflict of laws rules for the determination of the applicable national laws except for the provision in Article 60(1) EPC that for employee inventions the right to a European patent shall be determined in accordance with the law of the State in which the employee is mainly employed or in accordance with the law of the State in which the employer has the place of business to which the employee is attached. This rule is addressed to the national courts of the Contracting States assessing disputes concerning the right to a European patent as addressed in Article 61(1) EPC. The EPC does not contain, in particular, any conflict of laws rules applicable to the transfer of rights from an applicant other than the inventor(s) to the successor(s) of such applicant (see e.g. T 205/14, Reasons, point 3.6.5; T 725/14, Reasons, point 4.3; T 1201/14, Reasons, point 3.1.2).

63. Conflict of laws rules concerning the succession under Article 87(1) EPC could refer to a range of different national laws. In T 1201/14 the following possibilities were listed (Reasons, point 3.1.2):

a) the law of the country where the first application was filed ("lex originis");

b) the law of the country where the subsequent application was filed ("lex loci protectionis");

c) the law of the country which is agreed upon in the relevant contract ("lex loci contractus");

d) the law of the country where at least one of the parties to the transfer has its residence ("lex domicilii").

64. Any one of these options is related to specific issues which may imply further uncertainties. For example, the freedom to choose the applicable law of a contract (e.g. an employment contract) may be limited and choice of law rules tied to the territory of the priority application or of the subsequent application (options a) and b) listed above) are difficult to apply where a patent territory does not coincide with the territory in which the relevant law applies (in the territory of US patents federal law and state laws apply, the territory of a European patent encompasses a multitude of jurisdictions with different laws). In sum, the private international law aspects of Article 87(1) EPC can be described as complex (see Moufang, in Schulte (ed.), Patentgesetz mit EPÜ, 11th ed., Hürth 2022, § 41 N 28).

65. So far, no clear preference has been expressed for any choice of law rule in the EPO case law (see Maibaum, Die rechtsgeschäftliche Übertragung des Prioritätsrechts bei europäischen Patenten, Hürth 2021, p. 24-30). In several cases before the boards of appeal, the succession under Article 87(1) EPC was assessed under different national laws for the same set of facts with the same result, and, as a consequence, the board did not have to decide which law was applicable. For example, in T 577/11, the board found that none of the appellant's lines of argument, which were based on the applicability of Italian and Dutch law, led to a finding favourable for the applicant (Reasons, point 6.3). In T 1201/14 (see Reasons, point 3.2), the appellant relied on four lines of arguments to support its entitlement to priority: a (retroactive) nunc pro tunc assignment under US law, an implicit transfer by virtue of a general policy under German law, a "direct transfer" under US law and an implicit transfer by virtue of a general policy under Taiwanese law. Since none of these lines of arguments was both admitted and accepted by the board, there was no reason to determine the applicable national law (Reasons, point 3.3).

66. In cases where the applicable national law is determined, national provisions are regularly applied by the boards of appeal. For example, the board in T 205/14, found that Israeli law was applicable and, relying on opinions of experts in that law, that Israeli law on service inventions did not provide for formal requirements to be fulfilled in the context of the transfer of the rights related to service inventions (Reasons, point 3.7). Parties are regularly requested to file evidence (such as a legal opinion from an independent law expert) concerning the effects of the applicable national laws (see already J 19/87, Facts and Submissions, point VIII).

67. For the referring board, it was "far from clear" that the legal requirement for the transfer of priority rights by agreement should be assessed under national law, as the EPC does not contain any conflict of laws rules (referring decision, Reasons, point 37). The referring board drew the conclusion from earlier case law that the EPC did not seem to impose any formal requirements for the transfer of priority rights by agreement. Consequently, it envisaged - at least for the situation addressed in question II - that an implicit agreement could be sufficient to bring about the transfer of the priority right for the EPC territory (Reasons, point 38).

Autonomous considerations discussed while assessing succession under Article 87(1) EPC

68. It has been deduced from the wording of Article 87(1) EPC (without reference to national law) that the transfer of the right of priority has to have been concluded before the filing of the subsequent European patent application (T 1201/14, Reasons, point 3.1.1.1; T 577/11, Reasons, point 6.5, Catchword 3; T 1946/21, Reasons, point 2.3). The requirement that the right of priority has to be transferred before the filing of the subsequent application can be described as a requirement based on autonomous substantive law under the EPC.

69. Another autonomous rule has been discussed in view of Article 72 EPC, although with different outcomes. In T 62/05, the board required an equally high standard of proof for the transfer of priority rights as the one required for the assignment of a European patent application, i.e. that the assignment of priority rights had to be in writing and had to be signed by or on behalf of the parties to the transaction (Reasons, point 3.9). In T 205/14, on the other hand, the application of Article 72 EPC to the transfer of a right of priority was rejected (Reasons, point 3.6; see also T 517/14, Reasons, point 2.7.1).

National case law under Article 87 EPC

70. If questions of entitlement to claim priority under Article 87(1) EPC arise in national proceedings, the court seised needs to address all issues concerning the applicant's identity or succession, including the determination and application of foreign laws. However, in proceedings before national courts, conflict of laws issues and the related application of foreign law tend to cause less concern than in proceedings before the EPO. On the one hand, national courts can rely on their applicable conflict of laws rules and the respective case law. On the other hand, the domestic (substantive) laws of the national court are often applicable, either because the applicable conflict of laws rules refer to it or because conflict of laws issues are not relevant in cases not having connections to more than one jurisdiction.

71. If the facts of a case involve one or more jurisdictions other than the court's own jurisdiction, the court's set of conflict of laws rules is applied by first qualifying the legal relationship at issue in view of the individual conflict of laws rule that may be applicable. Specific statutory conflict of laws rules for the transfer of priority rights do generally not exist in national legislations on private international law. German courts have found, for example, that the validity of the transfer of a right to claim priority is subject to the laws of the state of the priority application (lex originis) while the obligations between the assignor and the assignee are subject to the laws applicable to the contractual relationship between these parties (lex contractus) (see the summary in German Federal Court of Justice X ZR 14/17 - Drahtloses Kommunikationsnetz, point 68).

72. The referring decision (in Reasons, point 40) cited another decision of the German Federal Court of Justice (Bundesgerichtshof, BGH) where the German conflict of laws rules, including the Rome I Regulation (see below point 80) pointed to the applicability of German law, which did not require any particular formalities for the transfer of priority rights. In view of the relationship between the parties to the transfer and a research and development agreement concluded between them, the German Federal Court of Justice accepted that there was an implicit agreement ("konkludente Einigung") between the parties, which was sufficient to acknowledge priority for the European patent (BGH, X ZR 49/12 - Fahrzeugscheibe, points 12 to 18).

73. In a decision of the High Court of Justice of England and Wales (Accord v RCT [2017] EWHC 2711 (Ch)), entitlement to priority was critical because it could not be shown that the applicant's entitlement to priority had been secured by the date of the subsequent application (point 66). Reference was made to earlier case law which "accepted a significant softening to what otherwise might have been the rigour of the rule that the title must be secured by the time the international application is made, by accepting an analysis based on common law principles distinguishing the equitable and legal title to property". If such distinction could be made, it was sufficient for the applicant to hold "the equitable or beneficial title to the priority right" at the date of the application (point 67).

Transfer of different rights to the subsequent applicant claiming priority

74. The figure below shows in a simplified manner how an inventor (or their employer or other legal successor) may obtain international patent protection, using the priority system established under the Paris Convention.

75. The inventor may apply for a patent in every territory or may transfer the right to obtain a patent to separate applicants for the different territories. Inventors often assign the right to the patents in all territories to a single applicant who then files a priority application. Within the priority period, the priority applicant or other applicants may file patent applications in other territories which benefit from the application date of the priority application (i.e. the priority date).

76. The dashed and the dotted lines represent the right to file a patent (evolving into the title to the patent application after filing in the respective territory). Applicant B may obtain the right to file a patent for territory 2 from the priority applicant who acquired the rights for all territories from the inventor. Applicant B may also acquire the right to file a patent for territory 2 directly from the inventor. Within international groups of companies, the inventor's employer company may acquire the rights for all territories and then vest its subsidiaries in the different territories with the patent rights for the respective territories. These possibilities reflect the fact that the title to a patent application is a property right that is established and may be transferred for each territory in accordance with the laws of the respective territory.

77. The priority right (straight lines) may be obtained only as a consequence of the filing of the priority application (see below points 83 ff). The priority applicant needs to provide any subsequent applicant with the documents required in the respective territory for claiming priority. The priority right remains relevant for the subsequent application and any patent based thereon but it is not relevant for the priority application.

78. If the priority applicant (Applicant A) transfers the title to the subsequent application to the subsequent applicant (Applicant B), this transfer is normally realised together with the transfer of the priority right (encircled arrows). In the agreements discussed in priority entitlement cases, no distinction is usually made between the two transfers (see below points 93 ff). Also in the existing EPO case law under Article 87(1) EPC (see above points 58 ff), it is not always clear whether the transfer at issue encompasses only the priority right or also the title to the subsequent European application. However, the fact that different parties are potentially involved in the transfer of the different rights already shows that a clear distinction should be made between the title to the subsequent application and the priority right, i.e. the right to attribute the date of the priority application to this application. As will be shown in the following paragraphs, only the transfer of the priority right (straight line) is relevant for the proceedings before the EPO for the purposes of Article 87(1) EPC.

Competence and applicable law for the transfer of the different rights invoked by the subsequent applicant

Title to the subsequent application

79. In proceedings before the EPO, the applicant shall be deemed to be entitled to exercise the right to the European patent (Article 60(3) EPC). The EPO has no power to decide a dispute as to whether a particular applicant is legally entitled to apply for and be granted a European patent in respect of the subject-matter of a particular application. The determination of questions of entitlement to the right to the grant of a European patent prior to grant is governed by the "Protocol on Jurisdiction and the Recognition of Decisions in respect of the Right to the grant of a European patent" (the "Protocol on Recognition"), which is an integral part of the EPC (G 3/92, OJ EPO 1994, 607, Reasons, point 3). The Protocol on Recognition governs the jurisdiction of the national courts of the Contracting States for disputes on entitlement to European patent applications. After grant, the national courts are competent to decide on disputes on the title to the European patent for each of the designated Contracting States. During disputes on the right to the grant of a European patent, the proceedings for grant before the EPO are regularly stayed in accordance with the provisions of Rule 14 EPC.

80. Disputes on the title to a European patent application or patent are resolved by the national courts by first determining the applicable law, applying their conflict of laws rules. These rules form part of the respective legislation on private international law but there are attempts to harmonise conflict of laws rules. For example, EU Regulation 593/2008 of 17 June 2008 on the law applicable to contractual obligations (Rome I Regulation) provides uniform conflict of laws rules for contractual obligations in civil and commercial matters.

81. Article 60(3) EPC applies to the applicant of any European patent application, regardless of whether it is a priority or first application or a subsequent application. In the case depicted in the figure above (point 74), assuming that the subsequent application is a European patent application, the national courts would be competent to decide on the title to this European patent application in accordance with the Protocol on Recognition.

82. As far as the title to the priority application is concerned, Article 60(3) EPC is not directly applicable, unless the priority application is a European application. If the title to the subsequent European patent application has been acquired from the priority applicant, national courts may have to assess under the applicable national laws who was entitled to the priority application in order to establish the chain of transfers leading to the subsequent applicant.

Right to claim the priority date for the subsequent application

83. According to decision T 205/14 (Reasons, point 3.3), the right to priority, that is, the right to claim priority for a European patent application from the filing date of an eligible "first application" or "previous application" originates in the applicant of the first application. The prevailing literature also assumes that the first application, not only a subsequent application, establishes the priority right under the Paris Convention (see Wieczorek, Die Unionspriorität im Patentrecht, Köln etc. 1975, p. 21, with further references). The filing of a first application may be seen as the creation of a bundle of potential priority rights that come into existence and may be examined only when they are invoked in a subsequent application.

84. For the subsequent application, priority rights are governed exclusively by Articles 87 to 89 EPC (see above point 25). It may be discussed whether the priority right with the priority applicant is established under Article 87(1) EPC or under the Paris Convention. In any case, no national laws are involved when a priority right is created or claimed for a subsequent application. This is a significant difference to the title to a European patent application or patent, which depends upon national laws (for example, employment law or property law).

85. Since the creation, the existence and the effects of the priority right are governed only by the EPC (and by the Paris Convention through its relationship with the EPC), priority rights are autonomous rights under the EPC and should be assessed only in the context of the EPC, regardless of any national laws.

86. Consequently, the entitlement to claim priority (and any related assignments of priority rights) should also be assessed under the autonomous law of the EPC. There are decisions that have approached the transfer of priority rights under autonomous rules (see above point 68 for the requirement that the priority right is assigned before the filing of the subsequent application and point 69 for the requirement of a written agreement). The Enlarged Board endorses the assessment of priority entitlement under the autonomous law of the EPC but not necessarily all rules discussed in this context in the existing case law. The autonomous requirements for the valid transfer of priority rights should not be stricter than national rules applicable to the transfer of priority rights or other property rights. As the referring board noted, the EPC does not impose any formal requirements for the transfer of the priority right by agreement (referring decision, Reasons, point 38).

87. A decision of the Court of Appeal of the Hague in the case Biogen/Genentech v Celltrion of 30 July 2019 quoted in the referring decision (Reasons, point 36) applied the EPC as the lex loci protectionis for the assessment of the validity of a priority claim. From the perspective of the EPC, the legislation of the EPC and related international treaties, such as the Paris Convention and the PCT, is autonomous.

88. It has often been discussed whether Article 60(3) EPC could be applied by analogy to the "right of priority" addressed in Article 87(1) EPC. Such application by analogy would result in a legal fiction (for the purposes of the proceedings before the EPO) that the subsequent applicant is deemed to be entitled to exercise the "right of priority" if the formal requirements are fulfilled. The main argument supporting such application by analogy was that the difficulties related to an assessment of the title to the application by the EPO (applicability of national laws, lack of conflict of laws rules etc.) would apply equally to the assessment of entitlement to priority. This argument in favour of an application of Article 60(3) EPC by analogy is of course not pertinent if entitlement to priority is assessed exclusively under the autonomous law of the EPC.

89. It is undisputed that Article 60(3) EPC is not directly applicable to disputes about the transfer of the "right of priority". In a codified system that has adopted the principles set forth in Articles 31 and 32 of the Vienna Convention on the Law of Treaties, a judge can establish rules going beyond the literal meaning of a legal provision (whether by analogy or otherwise) only if there is a lacuna in the law, in particular where situations arise for which the legislator has omitted to provide (see G 1/97, OJ EPO 2000, 322, Reasons, point 3(b)). If the legislator did not want to include a provision for certain situations, there is no lacuna to fill (see G 2/04, OJ EPO 2005, 549, Reasons, point 2.1.2; see also Schachenmann, Die Methoden der Rechtsfindung der Grobetaen Beschwerdekammer, GRUR Int. 2008, 702, section IV). As has been shown by many contributors to the discussions in the present referral, the drafters of the EPC did consider that disputes about the entitlement to priority could arise (e.g. by discussing whether subsequent applicants should be obliged to file specific evidence of their right to claim priority). The Enlarged Board thus concludes that the drafters intentionally left open the question of the EPO's competence to decide on the priority entitlement. Consequently, there is no lacuna in this respect that could be filled by an application by analogy of Article 60(3) EPC.

90. Another argument invoked by many stakeholders against the EPO's competence to assess entitlement to priority is the separation of powers between national courts and the EPO enshrined in Article 60(3) EPC, which avoids the need for the EPO to apply national laws (see e.g. Bremi, A New Approach to Priority Entitlement: Time for Another Resolving EPO Decision, GRUR Int. 2018, 128, 130). Such separation of powers can be respected even when the EPO is competent to assess priority entitlement if a clear distinction is made between, on the one hand, the priority right and its transfer as a matter governed by the autonomous law of the EPC and assessed by the EPO, and, on the other hand, the title to the subsequent application and its transfer, which is governed by national laws and assessed by national courts.

91. Furthermore, acknowledging the EPO's competence to assess priority entitlement respects the argument that the EPO, in view of Article 87(1) EPC, has to assess all aspects of the right of priority and that no distinction should be made between the "where", "what" and "when" requirements on the one hand and the "who" requirement on the other hand (T 844/18, Reasons, points 12 to 20). If all four requirements relevant under Article 87(1) EPC are assessed by the EPO, the EPO is competent for all aspects that may be relevant to determine the prior art, enabling it to assess all aspects of patentability. In contrast, national courts would remain competent to assess entitlement to the patent application or patent without getting involved in any questions related to patentability.

92. Even if the "who" requirement underlying Article 87(1) EPC is related to entitlement issues, it is clearly a criterion relevant for the validity of the patent based on the subsequent application since it is relevant for the delimitation of the prior art. Entitlement may be relevant in other contexts of prior art determination, e.g. where it is disputed whether certain information or use of items was made available to the public in the terms of Article 54(2) EPC. If the EPO can assess all aspects of the determination of prior art, the EPO's finding on patentability is based on a comprehensive assessment. If the EPO was barred from assessing priority entitlement, situations could arise in which the EPO has evidence potentially affecting the patentability of an invention but cannot use such evidence in its decision on patentability. Disputes on the entitlement to the patent, on the other hand, do not affect the EPO's findings on the patentability of the invention and the evidence and assessments underlying such findings, such as the EPO's determination of the relevant prior art.

National and autonomous considerations on the succession under Article 87(1) EPC

Priority entitlement and contractual succession assessed under national laws / by national courts

93. Agreements under which the subsequent applicant acquires the title to the subsequent application and the right of priority usually fail to distinguish between the two rights. For example, most employment agreements under which inventors who filed the priority application assign their rights to a subsequent applicant describe the object of the assignment in a very generic way (e.g. "any and all rights related to the invention in any jurisdiction". The agreement quoted in T 1201/14 (Reasons, point 3.2.1.1) refers to "the entire right, title and interest throughout the world in and to the invention" and adds "including ... the right to claim priority based on the filing date of the [priority application]". Such clause could be read as distinguishing between the title to the subsequent European application ("title ... throughout the world") and the right to claim priority based on the earlier US application. However, such specific references to the priority right are rare, particularly in employment agreements which are often the basis for the transfer of the right to the patents and of the respective priority rights.

94. In a decision of 2018, the German Federal Court of Justice (Bundesgerichtshof, BGH, case X ZR 14/17 - Drahtloses Kommunikationsnetz) analysed the differing views on the nature of the priority right in different Contracting States of the EPO: German literature and jurisprudence, on the one hand, consider the priority right to be an independent property right that may be assigned from the applicant of the priority application to a third party as its successor in title. In the English jurisprudence, on the other hand, the person having the rights to the invention is considered to be the "successor in title" for the purposes of the priority right (point 62). The German Federal Court of Justice concluded, however, that both views led to the same result in cases where, after the filing of the priority application, the title to the invention is transferred from the applicant of the priority application to the applicant of the subsequent application since the transfer agreement for the subsequent application regularly has to be interpreted in a way that it tacitly encompasses the right to claim priority for the subsequent application (point 63).

95. In the treaty of Bodenhausen on the Paris Convention (above point 30, see p. 37) and in an amicus curiae brief (IP Federation), reference was made to a French decision of 1962 (TGI Valence of 16 February 1962, Ann. 1963, 313-328). This decision found that the priority right is not an independent right which can be assigned on its own but a right that can only be assigned simultaneously with the right for the assignee to file a patent application in another country. In one of the English decisions referred to in "Drahtloses Kommunikationsnetz", the court held that the "successor in title" in Article 4A(1) Paris Convention must mean successor in title to the invention (High Court of Justice of England and Wales, Edwards v Cook [2009] EWHC 1304 (Pat), point 93). The High Court of Justice of England and Wales later held that "[u]sually the right to claim priority goes with the right to the invention" (High Court of Justice of England and Wales (Accord v RCT [2017] EWHC 2711 (Ch), point 75).

96. Also national statutes implementing Article 4(1) Paris Convention appear to be based on the assumption that the acquisition of the title to the subsequent application automatically entitles the respective applicant to claim priority (see Article 18(2) Swiss Patent Act: "The right of priority may be claimed by the first applicant or the person who has acquired the right belonging to the first applicant to file a patent application in Switzerland for the same invention."). Other Contracting States of the EPC have not adapted their national laws to the 1911 amendment of the Paris Convention (above point 30); the "successor in title" is still missing from e.g. § 41 of the German Patent Act and Article 9 of the Dutch Patent Act).

97. Thus, it may be concluded that within Europe there are differing views on the relevance of the "right of priority" addressed in Article 87(1) EPC as a property right separate from the title to the subsequent application for which the priority is claimed. There is a widespread view that the priority right is a mere ancillary right to the right to the subsequent patent application or patent which automatically follows any transfer of the title to the patent application or patent or, depending on the jurisdiction, that the title to the subsequent application automatically implies priority entitlement. These views however do not consider the possibility that the title to the subsequent application has not been acquired from the priority applicant (see above the figure in point 74). They also do not sufficiently reflect the fact that the priority applicant does not just transfer a right but needs also to provide active support to the subsequent applicant wishing to benefit from this right.

98. Such disregard for the priority right or its interpretation as a mere ancillary right to the right to the subsequent application may however partly explain why the priority right is rarely addressed in agreements on the transfer of the patent right. If a priority right is tacitly transferred together with the right to the corresponding patent or patent application, it may be assumed that the same conditions and formal requirements apply to the transfer of both rights. If a transfer of a priority right is not considered necessary in view of the priority entitlement, there cannot be any formal requirements for such transfer. In any case, the Enlarged Board is not aware of national statutes or case law setting higher formal requirements for the transfer of the priority right than for the transfer of the right to the patent application.

Consequences for the autonomous assessment of transfers of priority rights

99. In most jurisdictions, rights to obtain a patent can be transferred without any written agreement or other formalities (e.g. from an employee inventor to the employer who wishes to obtain patent protection in multiple territories). The right to priority automatically follows the title to the subsequent patent application in many jurisdictions and may thus also be transferred informally. If national laws establish low or no formal requirements for the transfer of priority rights, the autonomous law of the EPC should not establish higher formal requirements than those established under national laws that may be relevant in the context of a European application. To the contrary, the EPO should adapt itself to the lowest standards established under national laws and accept informal or tacit transfers of priority rights under almost any circumstances.

100. For example, the autonomous law of the EPC should not require that the assignment of priority rights has to be in writing and/or has to be signed by or on behalf of the parties to the transaction (see above point 69 for the diverging case law on this issue) since this would establish a high threshold in view of the national laws. Even the requirement that the transfer of the right of priority needs to be concluded before the filing of the subsequent European patent application (above point 68) is questionable in the Enlarged Board's view. If there are jurisdictions that allow an ex post ("nunc pro tunc") transfer of priority rights (see the extensive discussion of such transfers under US law in T 1201/14), the EPO should not apply higher standards. The "rigour of the rule" that the transfer must be completed before the filing of the subsequent application underwent a "significant softening" also in a 2017 decision of the High Court of Justice of England and Wales (see above point 73). However, the allowability of a retroactive transfer of priority rights may have limited practical relevance if priority entitlement is presumed to exist on the date on which priority is claimed for the subsequent European application (see below point 109).

Rebuttable presumption of entitlement to claim priority

101. Low standards for a valid transfer of priority rights not only serve the purpose of harmonisation with national laws that could be applicable instead of the autonomous law of the EPC. They serve the purpose of priority rights, namely to facilitate international patent protection, by reducing the risk that the inventors' (or their legal successors') interest in obtaining patent protection in multiple jurisdictions is jeopardised by formal requirements they may inadvertently fail to meet.

102. Any party transferring the right to a subsequent application wishes, under normal circumstances, that the subsequent applicant may benefit from the priority right. The Enlarged Board agrees with respondent I in that it is difficult to imagine a realistic scenario in which a party would transfer their rights to the invention but intentionally withhold the relevant priority right (see p. 8 of respondent I's letter of 5 May 2023). This applies also in cases where the title to the subsequent application is not transferred from the priority applicant (see the figure in point 74). The title to the priority application and the title to the subsequent application originate from the same inventor who normally desires that the priority is valid for all subsequent applications. In this context, it must be assumed that the priority applicant who has not acquired the right to the subsequent application accepts or at least tolerates the use of the priority by the subsequent applicant.

103. The content of the priority application is, in general, not published or otherwise made accessible to third parties before the expiry of the twelve-month time limit for filing subsequent applications. A copy of the priority application must be filed with the EPO within sixteen months after the filing of the priority application under Rule 53(1) EPC while the publication of the priority application normally occurs eighteen months after its filing date. Moreover, the applicant of the subsequent European application must provide documentation that cannot normally be obtained without the cooperation of the priority applicant. In particular, a copy of the priority application certified as correct by the authority where the priority application was filed, must be filed with the EPO (Rule 53(1) EPC, see also Article 4D(1) Paris Convention).

104. These formal requirements for claiming priority in accordance with Article 88(1) EPC can only be met by the subsequent applicant if the priority applicant provides the necessary support completely and in time. The fulfilment of these requirements can thus be seen as strong factual evidence of the priority applicant's approval of the subsequent applicant's entitlement to priority.

105. The Enlarged Board comes to the conclusion that entitlement to priority should in principle be presumed to exist to the benefit of the subsequent applicant of the European patent application if the applicant claims priority in accordance with Article 88(1) EPC and the corresponding Implementing Regulations. This conclusion is reached taking into account (i) that the priority applicant or its legal predecessor must under normal circumstances be presumed to accept the subsequent applicant's reliance on the priority right, (ii) the lack of formal requirements for the transfer of priority rights and (iii) the necessary cooperation of the priority applicant with the subsequent applicant in order to allow the latter to rely on the priority right.

106. The presumption also applies if the title to the subsequent application has not been acquired from the priority applicant but from a third party having the right to the invention in the respective territory (for example, from the inventor, see above the figure in point 74). Also in this situation, the priority applicant must provide the necessary support under Article 88(1) EPC, and the common predecessor with respect to the title to the two applications must be deemed to consent to the subsequent applicant's reliance on the priority right like any priority applicant assigning the title to the subsequent application.

107. The considerations leading to the presumption of priority entitlement apply to any case in which the subsequent applicant is not identical with the priority applicant but receives the support of the priority applicant required under Article 88(1) EPC. It does not matter whether the subsequent European application stems from a PCT application. It is also not relevant whether and to which extent the members of a plurality of co-applicants for the priority application overlap with the group of co-applicants for the subsequent application.

108. The presumption should be rebuttable since in rare exceptional cases the priority applicant may have legitimate reasons not to allow the subsequent applicant to rely on the priority. Such circumstances could, for example, be related to bad faith behaviour on the side of the subsequent applicant or to the outcome of other proceedings such as litigation before national courts about the title to the subsequent application.

109. Priority entitlement is not relevant before the priority is claimed by the subsequent applicant in accordance with Rule 52 EPC, normally at the filing date of the subsequent application or otherwise within sixteen months from the filing date of the priority application. Consequently, the presumption of entitlement exists on the date on which the priority is claimed and the rebuttal of the presumption must also relate to this date. Later developments cannot affect the rebuttable presumption.

110. The rebuttable presumption involves the reversal of the burden of proof, i.e. the party challenging the subsequent applicant's entitlement to priority has to prove that this entitlement is missing. If there is a strong presumption, the hurdle for rebutting it is higher than in the case of a weak presumption (see T 63/06, Reasons, point 3.2 for the rebuttal of the presumption of sufficiency of disclosure). The presumption that the subsequent applicant is entitled to the priority right is a strong presumption under normal circumstances since the other priority requirements (which establish the basis for the presumption of priority entitlement) can usually only be fulfilled with the consent and even cooperation of the priority applicant (see above points 104 ff). The party challenging the entitlement to priority can thus not just raise speculative doubts but must demonstrate that specific facts support serious doubts about the subsequent applicant's entitlement to priority.

111. Like the priority entitlement in general (see above points 85 f), the presumption of its existence and the rebuttal of this presumption is subject to the autonomous law of the EPC only. Consequently, there is no room for the application of national laws on legal presumptions and their rebuttal.

Specific arguments forwarded during the referral proceedings in the context of question I

Legal certainty and uniform legal situation in the designated Contracting States

112. The Enlarged Board has come to the conclusion that the EPO is competent to assess priority entitlement and that a rebuttable presumption in favour of the applicant's entitlement to priority is justified in view of the purpose of the priority rights, the lack of formal requirements for the transfer of priority rights and the presumed common interest of the priority applicant and the subsequent applicant (who have to cooperate when the priority is invoked).

113. In the context of priority entitlement, the requirement of legal certainty would be best served if third parties could easily, based on publicly available data, assess whether the subsequent applicant is the successor in title addressed in Article 87(1) EPC. This assessment is difficult for third parties already because the relevant documents are normally non-public and in the possession of the applicant or patent proprietor only. The rebuttable presumption of priority entitlement serves the purpose of legal certainty insofar as the applicant or patent proprietor as well as third parties can or should rely on the subsequent applicant's entitlement to priority unless specific facts support serious doubts about such entitlement.

114. The requirements of legal certainty and fairness in the individual case may conflict, and it may be argued that the presumption of a priority entitlement that is unjustified in a specific case disadvantages third parties, i.e. potential opponents. In this context it should be considered that even if a "wrong applicant" claims priority for its subsequent application, this does not necessarily mean that the priority right cannot be relied on. In national proceedings concerning the title to the subsequent application or the priority application, the priority entitlement issue can be resolved, for example if the outcome of such national proceedings is that the priority applicant and the subsequent applicant are found to be identical. In this context, it may be noted that the EPC explicitly foresees the ex tunc assignment of priority rights, at least in the context of disputes on the right to the patent before national courts: if a person other than the original applicant is found to be entitled to the grant of the European patent, this person may choose to file a new European patent application in respect of the same invention under Article 61(1)(b) EPC. To such new applications, Article 76(1) EPC "shall apply mutatis mutandis" according to Article 61(2) EPC. Under Article 76(1) EPC, "[t]he divisional application shall be deemed to have been filed on the date of filing of the earlier application and shall enjoy any right of priority". This means that the new application filed by the rightful applicant under Article 61(1)(b) EPC is deemed to have been filed on the date of filing of the earlier application and to have the benefit of any right of priority (G 3/92, OJ EPO 1994, 607, Reasons, point 5.4). In view of legal certainty, it should thus be considered that there is always a party who is entitled to claim priority - even if this party must be determined in national proceedings. Consequently, third parties can never fully rely on the invalidity of a priority and on the potential invalidity of a patent which may result from such lack of priority entitlement.

115. The EPO's competence to assess priority entitlement does of course not imply that national courts are bound by the EPO's assessments. In national proceedings concerning the validity of a European patent, relevant priority rights can be assessed taking into account all aspects, i.e. not only in view of the "same invention" criterion but also with respect to priority entitlement. A uniform legal situation in all designated Contracting States can therefore never be guaranteed. However, challenges to priority entitlement before national courts are subject to national restrictions (such as rules affecting the right of third parties to challenge entitlement to priority) - regardless of how the EPO assesses priority entitlement.

Interest of third parties to challenge entitlement to priority

116. Unlike disputes on the title to the patent application, in which normally only the applicant and other parties claiming rights to the invention are involved, challenges to the entitlement to claim priority are usually instituted by third parties, in particular by opponents. It has been argued that in a situation where the priority applicant and the subsequent applicant are in "perfect all-time agreement" on the transfer of the priority right, it was absurd that the priority could be declared invalid and a patent be revoked as a consequence (Bremi, A New Approach to Priority Entitlement: Time for Another Resolving EPO Decision, GRUR Int. 2018, 128, 131). The question whether there can be a public interest in allowing a third party to invalidate patents based on legal flaws related to the entitlement to priority arises both in proceedings before national courts and in proceedings before the EPO. In a decision of the High Court of Justice of England and Wales (Accord v RCT [2017] EWHC 2711 (Ch)), it was held that there was "no obvious public interest in striking down patents on this ground, unlike all the other grounds of invalidity" (point 77).

117. It is a matter of national law whether national courts should acknowledge a legitimate interest of a third party to obtain a decision on who is entitled to claim priority under Article 87(1) EPC. In the EPC however, there are no restrictions on who can file an opposition. If the EPO is competent to assess all aspects of priority (above point 91) together with all patentability requirements ex officio in examination proceedings or on the request of an opponent, the EPO cannot refuse to assess a priority entitlement objection based on who raised the objection. The rebuttable presumption concerning priority entitlement however substantially limits the possibility of third parties, including opponents, to successfully challenge priority entitlement.

Entitlement to priority in the context of PCT applications

The "PCT joint applicants approach"

118. The PCT joint applicants approach implies that in a PCT application where parties A and B are applicants for different designated States, both applicants may rely on the priority right derived from a priority application filed by only one of the applicants, without the need for any transfer of priority rights (above point 11). Even if the "joint applicants approach" is acknowledged for regular European patent applications (see above point 10, T 1933/12), the use of this approach for a PCT application with different applicants for different designated territories is questionable and has been questioned in the referring decision (see Reasons, points 30 to 33).

119. Under Article 118 EPC - a provision regularly quoted in support of the "joint applicants approach" -, different applicants for different designated Contracting States shall be regarded as joint applicants or proprietors for the purposes of the proceedings before the EPO, and the patent shall be uniform for all designated States. Exceptions from the uniformity of the European patent are foreseen in Article 118 EPC and may be justified, for example, by prior rights based on national patent applications (Article 139(2) EPC).

120. The PCT does not contain a provision like Article 118 EPC, which would impose a common procedural role throughout the grant proceedings to a plurality of applicants and prescribe the uniformity of the patent for different designated territories. A PCT application, after being accorded an international filing date, has the effect of a regular national application in each designated State (Article 11(3) PCT) which is prosecuted by the respective applicant for each designated State. The examination is carried out by the patent offices of each designated territory according to its own rules. The PCT does not exclude that different priority rights exist for different designated territories, be it for material reasons (e.g. the "same invention" criterion may be interpreted differently and is dependent on the subject-matter claimed before the respective patent office), be it for formal reasons (e.g. the applicant for one territory may not be entitled to a priority right while another applicant for another territory is entitled to claim priority stemming from the same priority application).

121. However, a general decision on the viability of the PCT joint applicants approach is not needed. The concept of an implied agreement (below points 122 ff) should allow an assessment leading to the same result as the PCT joint applicants approach in most cases.

The concept of an implied agreement

122. Where no formal requirements for the transfer of priority rights exist, priority rights can be transferred under an informal or implicit agreement (see the German case referred to above in point 72, where an implicit agreement was found to be sufficient to acknowledge priority entitlement). In the situation addressed in question II, the priority applicant (party A) actively presents itself together with the other subsequent applicant (party B) as an applicant to the office where the subsequent application is filed. Together they claim priority from the priority application of party A to the benefit of both parties. Even if the subsequent PCT application may be filed by a joint representative, the priority applicant should know about the details of this application and the related proceedings, including the claiming of priority that also benefits its co-applicant.

123. The Enlarged Board concurs with the referring board in that in the circumstances described in question II, the mutual filing demonstrates - absent indications to the contrary - the existence of an implicit agreement between party A and party B, conferring party B the right to benefit from the priority for the EPC territory (referring decision, Reasons, point 38).

124. The joint filing of the PCT application cannot in every case establish final proof of the existence of an implied agreement. However, under normal circumstances it can be assumed that the priority applicant and co-applicant for the subsequent application (party A) agrees that the subsequent application should take the full benefit of the priority for all applicants. Party A or its predecessors (including the inventor) normally have a common interest with party B in the validity of the priority for all territories encompassed by the subsequent PCT application.

125. The Enlarged Board concludes that, in the absence of clear indications to the contrary, the joint filing of the subsequent PCT application sufficiently proves that the parties entered into an implied agreement allowing party B to rely on the priority right established by the filing of the priority application by party A. Since the considerations leading to this conclusion not only apply in the context of PCT applications, the concept and the conditions for an implied agreement equally apply to co-applicants directly filing a subsequent European application if at least one of the co-applicants was an applicant for the priority application.

126. To put into question the implied agreement, evidence would be needed that an agreement on the use of the priority right has not been reached or is fundamentally flawed. For example, party B could act in bad faith to the detriment of party A who may then not be fully informed about the subsequent PCT application. A dispute between the parties at the relevant filing date was mentioned in an amicus curiae brief (efpia) as a further example (point 3.2). Factual indications putting into question the implied agreement have to be of a substantial nature and have to be presented by the party questioning the implied agreement. The implied agreement is to be assessed under the autonomous law of the EPC, which does not foresee any formal requirements for the transfer of priority rights (above point 86). Assessing the existence of an implied agreement under the autonomous law of the EPC is consistent with the approach chosen for the rebuttable presumption for the priority entitlement (above point 86) and appropriate in view of the object of the implied agreement, which is governed by the EPC and the Paris Convention only.

127. Transfers of private rights and underlying agreements are normally subject to national civil laws, but there are instances where the EPC regulates aspects of national civil laws in order to establish uniform standards (see e.g. Article 72 EPC on the form of the assignment of a European patent application or the development of an autonomous concept of universal succession in T 2357/12). In this context, it is justified in the Enlarged Board's view to consider the agreement implied by the joint filing of a subsequent application to be an agreement governed only by the autonomous law of the EPC.

128. An agreement (regardless of its form) can only be held against parties who were involved in the facts establishing the agreement. Co-applicants for the priority application who were not involved in the subsequent application may not be deemed to have consented to the reliance on the priority right by the other co-applicants for the priority application (a situation underlying e.g. T 844/18). The subsequent applicant(s) may however still be entitled to claim priority since the rebuttable presumption of entitlement does not depend on whether the involved applicants acted as co-applicants at any stage.

Implications for the referred questions

Question 1 - Competence of the EPO to assess priority entitlement

129. The subsequent applicant wishing to file a European patent application should not only hold the title to that European application (i.e. the right to the European patent) but also the priority right if such right is claimed for the European application. In the context of the EPC and the proceedings before the EPO, a strict distinction should be made between the two rights. The title to the subsequent application, on the one hand, is subject to national property laws. Its transfer is governed by national laws (to be determined in accordance with national conflict of laws rules) and assessed by national courts in view of Article 60(3) EPC (above points 79 ff). The right to claim the priority date for the subsequent European application, on the other hand, has been shown to be a right created under the autonomous law of the EPC and the Paris Convention, the transfer of which should also be assessed under the autonomous law of the EPC (above points 83 ff).

130. The exclusive application of the autonomous law of the EPC to the transfer of priority rights removes the need for conflict of laws rules and the application of national laws, thereby eliminating two main reasons invoked against the EPO's competence to assess whether a party is entitled to claim priority under Article 87(1) EPC. After evaluating various arguments supporting and denying this competence of the EPO (above points 83 ff, 93 ff), the Enlarged Board concludes that the EPO is competent to assess priority entitlement.

131. In view of the interests of the parties involved, the lack of formal requirements for the transfer of priority rights and the necessary cooperation between the priority applicant and the subsequent applicant in the context of the procedural requirements under Article 88(1) EPC, the Enlarged Board concludes that the entitlement to priority should be presumed to exist. This presumption should be rebuttable to take into account rare exceptional cases in which the claiming of the priority by the subsequent applicant appears to be unjustified (above points 101 ff).

132. If the requirements under Article 88(1) EPC are not fulfilled, the subsequent applicant is barred from claiming priority for this reason alone. The fulfilment of these procedural requirements is not covered by the rebuttable presumption. This is reflected in the order where compliance with Article 88(1) EPC and the corresponding Implementing Regulations is set as a condition for the rebuttable presumption of priority entitlement. The referral is not addressing any aspect of how these procedural requirements are addressed by the EPO.

133. Like the nature and the effects of the priority right and the entitlement to priority, the rebuttable presumption in favour of the priority entitlement is subject to the autonomous law of the EPC. It cannot be excluded, however, that in the context of the rebuttal of the presumption national laws need to be considered as well. For example, the existence of legal entities being parties in transfers of priority rights may be relevant and may need an assessment under national laws.

Question 2 - Priority entitlement in the situation addressed in question II

134. Question II addresses a specific situation in which the EPO has to assess priority entitlement (given the positive answer to question I). The question concerns a group of cases where an applicant other than the priority applicant wishes to rely on the priority right for a subsequent application jointly filed by both applicants. The considerations leading to the rebuttable presumption of priority entitlement apply regardless of whether the subsequent application is a PCT application and in any case where the priority applicant (as an individual or a group) is not identical with the subsequent applicant(s) (above points 101 ff, 107). The rebuttable presumption that the subsequent applicant is entitled to rely on the priority right derived from the priority application therefore fully applies to the situation addressed in question II.

135. For the situation addressed in question II, it has been proposed to extend the acknowledged "joint applicants approach" to a "PCT joint applicants approach" which has been questioned in the referring decision and by the Enlarged Board (above points 118 ff). As an alternative reasoning for a positive answer to question II, the concept of an implied agreement has been proposed not only by the referring board but also in certain amicus curiae briefs. The Enlarged Board concurs with the referring board in that in the circumstances described in question II, the mutual filing demonstrates - absent indications to the contrary - the existence of an implicit agreement between party A and party B, conferring party B the right to benefit from the priority for the EPC territory (referring decision, Reasons, point 38).

136. The Enlarged Board leaves open the validity of the "PCT joint applicants approach" but endorses the concept of an implied agreement. It therefore concludes that, in the absence of substantial factual indications to the contrary, the joint filing of the subsequent PCT application sufficiently proves that the parties entered into an implied or informal agreement allowing party B to rely on the priority right established by the filing of the priority application by party A.

137. An agreement cannot be implied if not all of a plurality of priority applicants are applicants or co-applicants for the subsequent application (the situation underlying e.g. T 844/18, above point 128). However, the rebuttable presumption of priority entitlement can be applied also in situations where one of the priority applicants is not involved in the filing of the subsequent application. In specific contexts, a priority applicant missing from the subsequent application may have reasons to claim the title to the subsequent application (in proceedings before national courts) or may possess evidence to rebut the presumption of priority entitlement in proceedings before the EPO.

138. The interpretation of a joint filing as sufficient proof for an implied agreement on the joint use of the priority right in the context of a joint PCT application may apply independently from the rebuttable presumption addressed in connection with referred question I. An implied agreement in the situation addressed in question II can however reinforce the presumption of entitlement to priority stipulated in view of referred question I.

Order

For these reasons, it is decided that the questions of law referred to the Enlarged Board of Appeal are answered as follows:

I. The European Patent Office is competent to assess whether a party is entitled to claim priority under Article 87(1) EPC.

There is a rebuttable presumption under the autonomous law of the EPC that the applicant claiming priority in accordance with Article 88(1) EPC and the corresponding Implementing Regulations is entitled to claim priority.

II. The rebuttable presumption also applies in situations where the European patent application derives from a PCT application and/or where the priority applicant(s) are not identical with the subsequent applicant(s).

In a situation where a PCT application is jointly filed by parties A and B, (i) designating party A for one or more designated States and party B for one or more other designated States, and (ii) claiming priority from an earlier patent application designating party A as the applicant, the joint filing implies an agreement between parties A and B allowing party B to rely on the priority, unless there are substantial factual indications to the contrary.

This decision G 0001/22 (Competence of the European Patent Office to assess whether a party is entitled to claim priority under Article 87(1) EPC (Entitlement to priority)) dd10-10-2023 (pdf) has European Case Law Identifier: ECLI:EP:BA:2023:G000122.20231010. The file wrapper can be found here. Figure taken from reason 74 of the decision.

 T 0438/19 of 27-06-2023 referred the following questions to the Enlarged Board of Appeal for decision:

1. Is a product put on the market before the date of filing of a European patent application to be excluded from the state of the art within the meaning of Article 54(2) EPC for the sole reason that its composition or internal structure could not be analysed and reproduced without undue burden by the skilled person before that date?

2. If the answer to question 1 is no, is technical information about said product which was made available to the public before the filing date (e.g. by publication of technical brochure, non-patent or patent literature) state of the art within the meaning of Article 54(2) EPC, irrespective of whether the composition or internal structure of the product could be analysed and reproduced without undue burden by the skilled person before that date?

3. If the answer to question 1 is yes or the answer to question 2 is no, which criteria are to be applied in order to determine whether or not the composition or internal structure of the product could be analysed and reproduced without undue burden within the meaning of opinion G 1/92? In particular, is it required that the composition and internal structure of the product be fully analysable and identically reproducible?

In the present opposition appeal case, the Board issued a summons to oral proceedings in Haar. The appellant (patent proprietor) requested that the oral proceedings be held by videoconference. No reasons were given for this request. The Board then issued a communication containing its provisional opinion. The parties were also informed that if the Board found it appropriate to do so, the oral proceedings might be held by videoconference. The parties were also asked to inform the Board if they wished to invoke any reasons against holding the oral proceedings by videoconference, for the case that the Board decided to use that format. The appellant repeated its request for oral proceedings by videoconference and stated that it knew of no reason why the oral proceedings could not be held by videoconference. The respondent invoked no reasons against holding oral proceedings by videoconference, but requested that the Board inform the parties as soon as possible if it decided to hold the oral proceedings by videoconference. Oral proceedings took place on the 25 April 2023 in person at the premises of the EPO in Haar. The Board argued that: 1. although the order of G 1/21 refers to an emergency situation, it follows from the ratio decidendi of this decision that in-person oral proceedings can only be denied under very limited conditions, even in a situation of general emergency such as a pandemic; 2. due to the fact that videoconferences, at least with current technology, can only provide a suboptimal form of communication, parties have a right to the optimum format for oral proceedings, i.e. in-person oral proceedings, that can only be denied under very limited conditions; and 3. e contrario it also follows from the reasons underlying the Enlarged Board's decision, that parties cannot force Boards to conduct videoconferences instead of in-person oral proceedings.

Today, the Boards of Appeal have published the News message shown below (no changes made, except emphasis added):

Press Communiqué of 23 March 2023 on decision G 2/21 of the Enlarged Board of Appeal

10 days

A news message on the epi website indicates that the Administrative Council of the EPOrg decided to amen to Rule 126(2) EPC relating to the date on which a document sent by the EPO is deemed to be delivered. Currently, a documnt is deemed delivered 10 days after the date on the document. This will changer per 1 November 2023: as of that date, the date on which the document is deemed to be delivered is the date on the document, similarly to PCT Rule 80.6, second part (with with some differences, in particular the EPO keeping the burden of proving the date of delivery in the event of dispute, whereas under PCT that burden is with the applicant). 

I heard that, surprisingly, only one delegation voted against the change. Even though the entry into force of the amended Rule is about a year away, changing such a well-established rule that is know world-wide to the disadvantage and risk of the applicant may cause some accidents, which cannot in all cases be repaired: not knowing that the rule has changed will make a request for re-establishment of missing, for example, the appeal period, have hardly any chance of success.

Note that the change has no impact on the 9m opposition period (triggered by the mention of the grant in the bulletin), the 1m period for paying the filing and search fee (triggered by the filing), the 6m period to pay the examination fee and file the request for  examination (triggered by the mention of the publication of the search report in the bulletin), the 31m period for EP entry (triggered by the earliest priority date), nor any other periods that are triggered by an event other than notification.
It does however affect all periods for responding to an invitation to remedy a formal deficiency (in most cases, 2m), an office action (usually 4m, sometimes 2m; extendible), a R.161/162 communication (6m), invitations to pay claims fees in case of non-unity (2m), the period for requesting further processing (2m), the appeal periods (2m for notice & fee, 4m for grounds), and all other periods  that are triggered by the notification of letter/invitation/communication! 

So, when,  a communication is issued on 17 November 2023 under Rule 58 to file a missing translation:
- if the current Rule would still have applied, a response would need to be filed by
         17/11/2023 + 10d + 2m -> 27/1/2024 (Saturday) [R.134(1)] -> 29/1/2024 (Mon);
- with the amended Rule however, a response is to be filed by
         17/11/2023 + 2m -> 17/1/2024 (Wed)

The Administrative council documents are currently not yet available on the EPO website (here).

Update 21 November 2022: the Administrative council documents are now available on the EPO website:

• CA/D 10/22 Decision of the Administrative Council of 13 October 2022 amending Rules 46, 49, 50, 57, 65, 82, 126, 127 and 131 of the Implementing Regulations to the European Patent Convention; amended Rules 46, 49, 50, 57, 65, 82 in force as of 1.2.2023; amended Rules 126, 127 and 131 in force as of 1.11.2023;
•  CA/30/22 Rev. 2 Legal changes to support digital transformation in the patent grant procedure (first basket): amendments to the EPC Implementing Regulations (Preparatory documents for the decision)

The epi news message is cited below (no changed made): 

The ten day rule is living its last months

October 14, 2022

In the present case, the examining division regarded several  paragraphs of the description to be at odds with independent claim 1, as amended.  The examining division equated the term "embodiment" with subject-matter that has to fall "within the scope of the invention as defined by the claims", and concluded that the description so adapted was not in conformity with the independent claims, contrary to Rule 42(1)(c) EPC, because the term "embodiment" was used in parts of the description that describe subject-matter that was not part of the subject-matter of these independent claims. Moreover, the examining division held that the "invention" must always be the "invention claimed" and the "invention" was defined by the independent claimws. The Board did not agree and held:
1) the EPC does not define that “the "invention" is necessarily and always to be equated with the "invention claimed"”, 
2) concluding from Art. 84 EPC that "embodiments" of the description of a patent application have to be within the scope of the (independent) claim cannot be derived from the EPC and can also also not be derived from the jurisprudence of the Boards of Appeal, and 
3) in particular Rule 42(1)(c) EPC cannot be the legal basis for establishing such a general and broad requirement for an adaptation of the description to the claims. It is simply not what this provision says.”
Herein, the Board deviates from the strict practice that the first instance nowadays applies as well as from Guidelines (2022) F-IV, 4.3. The Board does however not address the Guidelines, although that could have been expected in view of Art. 20(2) RPBA2020. Also, the Board hardly addresses the case law that the EPO considers to support the “delete all non-covered embodiments" approach that is used by the drafters of the Guidelines, and as a consequences do not discuss whether a referral to the Enlarged Board would be necessary acc Art. 20(1) RPBA2020. Note that the Board also does not mention T 1989/18 of 16.12.2021 that concluded that, as a general rule, not is not required to bring the description in line with (amended) claims intended for grant.

In the present case, the examining division issued a decision to refuse the application based on the ground under Article 123(2) EPC and on lack of novelty, lack of inventive step and lack of clarity. However, the examining division had issued only two communications before deciding to refuse the application: the first was a communication under Rules 161(1) and 162 EPC, inviting the applicant to correct any deficiencies noted in the written opinion raised by the EPO as ISA in the international phase, and the second was a communication under Rule 137(4) EPC headed "Invitation pursuant to Rule 137(4) and Article 94(3) EPC", accompanied by an annex raising an objection under Article 123(2) EPC and the statement: "nota bene: The amendment appears also not suitable to remedy the deficiencies". In the statement setting out the grounds of appeal, "the appellant contended among others that the examining division had committed a substantial procedural violation as, in the proceedings before the examining division, the appellant never had the opportunity to address the objections as expressed in the appealed decision. Moreover, with the invitation pursuant to Rule 137(4) EPC, the appellant had only been alerted that certain amendments had not been sufficiently identified and/or their basis in the application as filed has not been sufficiently indicated. The subsequent decision to refuse the European patent application without any further ado had come completely to the surprise of the appellant. Thus, the appellant submitted that the right to be heard under Article 113(1) EPC had been violated.".
The Board considered the scope of Art. 94(3) EPC in detail and considered that at least one substantive communication pursuant to Art. 94(3) EPC and Rule 71(1) EPC is required before a decision to refuse the application on substantive grounds is issued (or, exceptionally, summons for OP). The Board addressed in detail whether a communication under Rules 161(1) and 162 EPC can/cannot be considered a communication under Article 94(3) EPC and whether an "Invitation pursuant to Rule 137(4) EPC and Article 94(3) EPC" can/cannot considered a substantive communication under Article 94(3) EPC.

In the present case, the application was refused due to lack of novelty. The applicant appealed with a sole request in which the applicant amended the independent claims. The amendments included the addition of a feature to the independent claims which, according to a positive statement in the annex to the summons for oral proceedings before the examining division, made the claim novel. Nevertheless, interlocutory revision was not granted (possibly because the ED considered further amendments to extend subject-matter, but -in accordance with Art.109(2), the reasons were not given). The Board of Appeal discussed the breath and the established case law of Art.109(1) EPC, as well as the Guidelines, and considers it appropriate to point out that there are (still) some significant inconsistencies between the current Guidelines and the established case law as to the interpretation of Article 109(1) EPC. The Board concluded that "interlocutory revision must be granted if the amendments clearly overcome the grounds for refusal, even if further new objections arise, i.e. irrespective of whether new objections under Article 123(2) EPC or whether previous objections referenced in the appealed decision were raised by the first-instance department" and noted that "the established case law (...) and the current Guidelines are inconsistent with each other."  The Board conclude that, in the current case, "the appeal is "well founded" within the meaning of Article 109(1) EPC. There is also no apparent reason to contest that the appeal is "admissible" within the meaning of Article 109(1) EPC. The examining division should therefore have indeed rectified its decision and continued with the examination of compliance with the requirements of the EPC. However, for whatever reasons, they did not do so."

"(1) deleting the features 'via communication with an MME', 'the MeNB transmitting the CSG identity state information to the SeNB' and 'the MeNB determining whether the UE accesses the SeNB with an identity of a member or a non-member according to the CSG identity state information' which were previously added into claim 1 and did not contribute to patentability in view of the Examining Division. Hence, deleting the above features previously added into claim 1 does not extend the subject matter beyond the content of the application as filed;

(2) adding the last alternative feature of former claim 4 according to which 'if determining that the UE cannot access the SeNB, the SeNB refusing an SeNB adding request transmitted by the MeNB' [feature (c)];

(3) adding all features of former claim 5 'wherein a message for the SeNB refusing the adding request contains a cause value indicating that the SeNB refuses to be added or the CSG identity state information of the UE' [feature (d)];

(4) amending the execution entity 'MeNB' to read as 'SeNB' (basis for the amendment can be found at least in original claim 4 or rather on page 6, line 8 of the description as originally filed).

Further, former claims 4 to 6 have been cancelled.

In addition, former independent claim 14 (amended independent claim 11) has been brought in line with amended independent claim 1."

"3 Positive statement

3.1 It is noted that claims 6 and 20 are not disclosed by D4, since while paragraph [48], teaches that the SeNB decides whether to admit the UE based on the CSG status, it does not explicitly mention that the SeNB sends a cause value indicating the refusal.

It appears hence that the combination of claims 1+4+5+6 currently on file, due to the dependency of claim 6, which depends on 5, which depends on 4, which finally depends on 1, would be new over D4.

Claim 15 should be amended accordingly.

3.2 It is also underlined that the novelty objections based on document D2 is abandoned, since D2 seems not to disclosed [sic] the sending from MeNB to SeNB of the CSG status."

"The department concerned will rectify its decision if convinced in the light of the grounds of appeal that the appeal is admissible and well founded. This could arise, for example, because:... (iii) the decision of the department concerned does not appear to be incorrect, but the applicant ... files amendments to the application, which overcome the objections of the decision under appeal (see T 139/87)",

"If amendments clearly overcome the grounds for refusal, interlocutory revision is granted even if further new objections arise".

In the present case (T 1517/17, consolidated with T 2719/19), the patent proprietor filed an appeal to the interlocutory decision of the opposition division revoking its patent. The application on which the patent was granted had originally been filed as an international application under the Patent Cooperation Treaty (the PCT application). It claims priority on the basis of the US provisional patent application (the priority application). The priority application was filed in the name of the two inventors H. Wang and Z. Zhong. The PCT application names the same two persons as inventors and as applicants with designation for the US only. It also names as applicants Alexion Pharmaceuticals, Inc. and the University of Western Ontario as applicants for all designated States except the US. The patent in suit names Alexion Pharmaceuticals, Inc. as patent proprietor and R.P. Rother, H. Wang and Z. Zhong as inventors.

In the oral proceedings before the Legal Board of Appeal in the two DABUS cases earlier today, the Board decided that the appeal is dismissed and that the request for a referral to the Enlarged Board is refused.

The Board concludes that DABUS, an AI machine, cannot be considered an inventor in the meaning of the EPC, as the Board concluded that an inventor has to be a person with legal capacity.

During the oral proceedings, the appellant gave various arguments as to why a non-person inventor should be possible, including references to national law/rulings of EPC as well as non-EPC states. The appellant also argued that the EPO should not have checked the designation of the inventor (Art.60(3) and Rule 19(1) EPC), also not whether the inventor is a natural person or not, and that an incorrect opposition is also not a ground of revocation in proceedings before the EPO - it being decided under national law and being in the sole competence of the national courts.

The appellant also indicated that, in his opinion, one  reason for the designation of inventor is transparency, and that the designation of DABUS was transparent, correct and in his view according to the relevant principles of law. While the applicant could have prevented the issue by adding himself or another person as an inventor, it would not be have been correct and thus appropriate to incorrectly designate a fictitious person or a person that was not an inventor as the inventor, even though that would not have led to a refusal in view of Art.60(3) EPC. 

The debate address the relevance of Art.60(1) EPC (The right to a European patent shall belong to the inventor or his successor in title), Art.60(3) EPC (In proceedings before the European Patent Office, the applicant shall be deemed to be entitled to exercise the right to a European patent) and Rule 19(2) (The European Patent Office shall not verify the accuracy of the designation of the inventor) as well as Art. 81 first and second sentence (statement to the origin of the right to the European patent) and Rule 19(1) (The request for grant of a European patent shall contain the designation of the inventor. However, if the applicant is not the inventor or is not the sole inventor, the designation shall be filed in a separate document. The designation shall state the family name, given names and country and place of residence of the inventor, contain the statement referred to in Article 81 and bear the signature of the applicant or his representative.) The appellant also submitted that "successor in title" does not need to arise from a transfer, but may also derive from the ownership of DABUS (note: in the case as hand, the applicant did not just own DABUS, but also wrote its source code and operated it, so there was no other person that could be considered to be possibly entitled to the ownership): with DABUS being able to make inventions, its inventions would also be owned by its owner - fructus industriales, "the owner of a tree also owns the fruits of that tree".  

During the oral proceedings, the appellant also indicated was that there was a dilemma: the invention was not a natural person, while EP patents should be grantable for any inventions, also for AI-originated inventions. The appellant asked the Board, in case the would not grant any of the requests, whether the Board would know a solution to the dilemma. After the oral proceedings were closed, the chairman of the Board indicated that the Board did not find a solution for the situation the appellant is in. 

The full reasoning will be provided in the written decision.

File wrapper:  EP 18 275 163 (J 8/20) and EP 18 275 174 (J 9/20)
Also refer to our earlier blog post in respect of the refusal by the Receiving Section here.
The above comments reflect my personal understanding of what was discussed at the oral proceedings.

Update 22.12.2021: 

The EPO published a Press Release "AI cannot be named as inventor on patent applications" dated 21 December 2021, indicating that:

In public oral proceedings today, in combined cases J 8/20 and J 9/20, the Legal Board of Appeal of the EPO confirmed that under the European Patent Convention (EPC) an inventor designated in a patent application must be a human being. The board dismissed the applicant's appeal. The written decision and reasons will be issued in due course and will be available via the European Patent Register. The Boards of Appeal have issued a communiqué with further details.

The Boards of Appeal published a communiqué, which is cited in full below (emphasis added):

Press Communiqué on decisions J 8/20 and J 9/20 of the Legal Board of Appeal

21 December 2021

Today, the Legal Board of Appeal announced its decision to dismiss the appeal in cases J 8/20 and J 9/20. The Legal Board of Appeal confirmed the decisions of the Receiving Section of the European Patent Office to refuse the applications EP 18 275 163 and EP 18 275 174, in which an artificial intelligence system called DABUS was designated as inventor in the application forms. The Legal Board of Appeal also refused the auxiliary request according to which no person had been identified as inventor but merely a natural person was indicated to have "the right to the European Patent by virtue of being the owner and creator of" the artificial intelligence system DABUS.

Background

Under Article 81 EPC the applicant must designate the inventor. According to Article 60(1) EPC the right to a European patent belongs to the inventor or his successor in title.

In cases J 8/20 and J 9/20 the question arose as to whether the applicant, when applying for a European patent, can designate as inventor an artificial intelligence machine which does not have legal capacity. Applications designating the AI system DABUS as inventor were filed in multiple jurisdictions, including at the European Patent Office. The applicant argued that the inventions had been created autonomously by DABUS.

According to the European Patent Convention (EPC) the designation of the inventor is a formal requirement which a patent application must fulfil according to Article 81 EPC and Rule 19(1) EPC. Assessment of this formal requirement takes place prior to and independently from the substantive examination and involves no consideration as to whether the subject-matter of that application meets the requirements of patentability.

The Receiving Section of the EPO refused both applications. In its decisions it considered the designation submitted by the applicant not to be consistent with Article 81 EPC for two reasons. Firstly, it concluded that only a human inventor could be an inventor within the meaning of the EPC. For this reason, designating a machine as inventor did not comply with the requirements set out in Article 81 and Rule 19(1) EPC. Secondly, the Receiving Section was of the opinion that a machine could not transfer any rights to the applicant. The Receiving Section considered therefore that the statement that the applicant was successor in title because they owned the machine did not satisfy the requirements of Article 81 EPC in conjunction with Article 60(1) EPC.

Key considerations

At the end of the oral proceedings, the Legal Board of Appeal dismissed the appeal and orally provided the following reasoning in both cases:

The written decision with a detailed reasoning will be sent to the parties in due course and will subsequently be publicly available in the decisions database of the Boards of Appeal.

Contact

Nikolaus Obrovski

Jeannine Hoppe

Spokespersons of the Boards of Appeal of the European Patent Office

boa-press@epo.org

This press release is a non-binding document for media use.

Today, an EPO news message was published in the EPO website indicating that the President of the EPO and the President of the Boards of Appeal have proposed to the Administrative Council to relocate the Boards back from Haar to the city center, more specifically to Pschorr-Höfe 7 in Munich, owned by the EPO (Bayerstrasse area).

The news message reads:

Plan to relocate Boards of Appeal presented to EPO member states

14 December 2021

EPO President António Campinos and President of the Boards of Appeal Carl Josefsson have made a joint proposal today to the EPO's member states to relocate the Boards of Appeal from the Munich district of Haar to the city centre. A detailed proposal for the relocation of the Boards of Appeal will be presented for approval of the EPO member states by spring 2022.

Further information:

Joint declaration

Joint Declaration

of the President of the European Patent Office and

of the President of the Boards of Appeal

on the re-location of the Boards of Appeal

CONSIDERING the decision of the Administrative Council of 30 June 2016 (CA/43/16 Rev.1) on a comprehensive reform of the structures, management and career scheme of the Boards of Appeal aiming at improving the organisational autonomy of the Boards of Appeal and the perception of independence in their activities;

CONSIDERING the decision of the Administrative Council of 30 June 2016 (CA/D 6/16) amending the Implementing Regulations to the European Patent Convention and establishing the rules governing the organisation and management of the Boards of Appeal and President of the Boards of Appeal;

CONSIDERING the decision of the Administrative Council of 30 June 2016 (CA/D 7/16) setting up a Boards of Appeal Committee and adopting its Regulations;

CONSIDERING the decision of the Administrative Council of 30 June 2016 (CA/43/16 rev. 1 – Part C) concerning the relocation of the Boards of Appeal in a separate building in Munich;

CONSIDERING the decision of the Administrative Council of 16 October 2016 (CA/82/16) to conclude a rental agreement for the new location of the Boards of Appeal in Haar;

CONSIDERING the Memorandum of Understanding between the President of the Office and the President of the Boards of Appeal on the organisational autonomy of the Boards of Appeal, signed on 29 June 2019;

WHEREAS the rental contract for the building in Haar was concluded in 2017, for the duration of 15 years, ending in 2032, and an additional contract concluded in 2019, for the duration of 84 months, ending in 2026;

WHEREAS the Office will introduce the New Ways of working (CA 77/21) in 2022 for a three-year pilot;

The President of the Boards of Appeal and the President of the Office jointly propose to the Administrative Council to re-locate the Boards of Appeal from Haar to the building Pschorr-Höfe 7 in Munich, owned by the EPO, as of 2025/2026.

Munich, 10 December 2021

António Campinos           Carl Josefsson

President of the Office     President of the Boards of Appeal

The full decision was published today, 29 October 2021. 
In reason 32 of the decision, "Ihe Enlarged Board considers that the limitations currently inherent in the use of video technology can make it suboptimal as a format for oral proceedings, either objectively or in the perception of the participants, but normally not to such a degree that a party's right to be heard or right to fair proceedings is seriously impaired. If in an individual case these rights cannot be respected, it is of course the duty of the deciding body to take appropriate measures to remedy this."
In reason 45, the Enlarged Board indicates that "a hearing in person is the optimum format or, to use a term well known in the field of European patent law, it is the gold standard. It definitely fulfils the requirements of Article 113 EPC and Article 6 ECHR. It is also the format that the legislator had in mind when drafting Article 116 EPC. Therefore, in-person hearings should be the default option. Parties can only be denied this option for good reasons."
In reason 46, the Enlarged Board indicates that "[...] the holding of oral proceedings is seen as serving the interests of the parties. The vast majority of oral proceedings are held upon request by a party. It therefore makes sense that the choice of format for these oral proceedings can be made by the party who requested them and not by the board of appeal, especially as this concerns more than just an organisational matter. As stated earlier, the Enlarged Board holds that at this point in time videoconferences do not provide the same level of communication possibilities as in-person oral proceedings. A party may thus have good reasons to prefer in-person oral proceedings to a videoconference." (see reasons 47-50)

 Today, T 116/18 was published on the Recent Decisions pages of the Boards of Appeal, referring the following questions to the EBA (as G 2/12):

The following questions are referred to the Enlarged Board of Appeal for decision.

If for acknowledgement of inventive step the patent proprietor relies on a technical effect and has submitted evidence, such as experimental data, to prove such an effect, this evidence not having been public before the filing date of the patent in suit and having been filed after that date (post-published evidence):

1. Should an exception to the principle of free evaluation of evidence (see e.g. G 3/97, Reasons 5, and G 1/12, Reasons 31) be accepted in that post-published evidence must be disregarded on the ground that the proof of the effect rests exclusively on the post-published evidence?

2. If the answer is yes (the post-published evidence must be disregarded if the proof of the effect rests exclusively on this evidence), can the post-published evidence be taken into consideration if, based on the information in the patent application in suit or the common general knowledge, the skilled person at the filing date of the patent application in suit would have considered the effect plausible (ab initio plausibility)?

3. If the answer to the first question is yes (the post-published evidence must be disregarded if the proof of the effect rests exclusively on this evidence), can the post-published evidence be taken into consideration if, based on the information in the patent application in suit or the common general knowledge, the skilled person at the filing date of the patent application in suit would have seen no reason to consider the effect implausible (ab initio implausibility)?

Summary of Facts and Submissions

I. This decision concerns the appeal filed by the opponent (appellant) against the decision of the opposition division (decision under appeal) to reject the opposition against European patent No. 2 484 209 (patent in suit).

The patent in suit originates from European patent application No. 12002626.5, which is a divisional application of European patent application No. 05719327.8.

II. The patent in suit had been opposed pursuant to Article 100(a) EPC for lack of novelty (Article 54 EPC) and lack of inventive step (Article 56 EPC), Article 100(b) EPC for insufficiency of disclosure (Article 83 EPC), and Article 100(c) EPC for added matter (Article 123(2) EPC and Article 76(1) EPC).

III. The following documents, submitted before the opposition division, are relevant for the present decision:

D4 WO 03/015519 A1

D8 WO 2005/048711 A1

D8P1 DE 103 53 278.1

(first priority application of D8)

D8P2 DE 10 2004 006 075.4

(second priority application of D8)

D9 Experimental report - field trials (18 pages,

filed with the notice of opposition)

D10 Experimental report (2 pages, filed with the

notice of opposition)

D21 Additional Test Data (6 pages, filed by the

patent proprietor (respondent) with its letter dated 26 October 2016)

D22 Additional Test Data (21 pages, filed with the

respondent's letter dated 11 September 2017)

IV. The opposition division's decision can be summarised as follows.

- The grounds for opposition pursuant to Article 100(c) EPC (Article 123(2) and Article 76(1) EPC) did not prejudice the maintenance of the patent in suit as granted.

- The question of the conditions under which synergy was achieved was not relevant for sufficiency of disclosure as this effect was not expressed in the claims. This effect was part of the problem to be solved and had to be dealt with under inventive step. Therefore, the ground for opposition pursuant to Article 100(b) EPC did not prejudice the maintenance of the patent in suit as granted.

- The novelty objections based on D4 and D8 (prior-art documents pursuant to Article 54(2) and Article 54(3) EPC, respectively) were not convincing because at least two selections had to be made from their respective disclosures to arrive at claim 1 of the patent in suit as granted.

- D21 and D22 were admitted into the proceedings. The results in these documents and of test example 2 in the patent in suit proved a synergistic effect from combining thiamethoxam with compounds according to formula Ia of claim 1. The data in D9 and D10 had not been taken into account because, inter alia, the experiments described in them could not be reworked. In view of D4 as the closest prior art, the objective technical problem had to be seen as "the provision of insecticide compositions comprising anthranilamides out of the group disclosed in D4, together with an insecticidally active mixing partner, showing an advantageous enhanced efficacy." (decision under appeal, page 23, penultimate paragraph). The solution to this problem was not obvious because synergism was per se unpredictable.

Therefore, the ground for opposition pursuant to Article 100(a) EPC did not prejudice the maintenance of the patent in suit as granted.

V. With its statement of grounds of appeal, the appellant submitted the following document:

D23 Experimental report (8 pages)

The last two pages of the statement of grounds of appeal are headed "Annex 1" and show a calculation of the number of compounds covered by formula Ia in claim 1.

VI. As requested, the parties were summoned to oral proceedings. In preparation for the hearing, the board issued a communication pursuant to Article 15(1) RPBA 2020 with a preliminary opinion on certain issues relevant to the decision to be taken. With regard to the disputed requirement of plausibility, the board indicated that a referral to the Enlarged Board of Appeal might be necessary.

VII. By letter dated 19 April 2021, the appellant withdrew its previously formulated request that the appeal fee be refunded.

VIII. By letter dated 22 April 2021, the appellant submitted a copy of a correspondence between epi and the President of the European Patent Office.

IX. By letter of 22 June 2021, the respondent filed, inter alia, sets of claims of a second and a third auxiliary request and the following document:

D24 Selby, T. S., Lahm, G. P., Stevenson, T. M.,

"A retrospective look at anthranilic diamide insecticides: discovery and lead optimization to chlorantraniliprole and cyantraniliprole", Pest Manag. Sci., 73, 2017, pages 658 to 665

X. Oral proceedings before the board were held as a video conference on 22 July 2021.

At the hearing, the appellant's opening requests were that:

- the decision under appeal be set aside and that the patent in suit be revoked in its entirety

- D21 and D22 not be taken into account to prove the alleged synergy

- D24 not be admitted into the proceedings

- the respondent's pending auxiliary requests not be admitted into the proceedings

It did not maintain the following previously formulated requests that:

- the board order the respondent to file the original data set underpinning the results set out in the patent in suit

- the board order the hearing of witnesses capable of testifying as to the accuracy and completeness of the data set out in the patent in suit

The respondent's initial requests were that:

- the appeal be dismissed, implying that the patent in suit be maintained as granted (main request)

- alternatively, that the patent in suit be maintained in amended form based on the sets of claims of the first auxiliary request, filed with the letter dated 26 October 2016, or the second or third auxiliary requests, filed with the letter dated 22 June 2021

- if the main request was not allowable, that the case be remitted to the opposition division for further prosecution

- figures 1 and 2, shown in the statement of grounds of appeal, as well as the discussion relating to them, not be admitted into the proceedings

- D21 and D22 be taken into account to prove the alleged synergy

- D23 not be admitted into the proceedings

- D24 be admitted into the proceedings

During the oral proceedings, both parties additionally requested that questions be referred to the Enlarged Board of Appeal concerning the disputed requirement of plausibility.

During the oral proceedings, the board decided to:

- admit D23 into the proceedings

- admit figures 1 and 2, shown in the statement of grounds of appeal, as well as the discussion relating to them, into the proceedings

- not admit D24 into the proceedings

At the end of the oral proceedings, the parties confirmed their opening requests and in addition their requests for referring questions to the Enlarged Board of Appeal. The board concluded to continue the proceedings in writing.

XI. An observation by a third party was received on 6 October 2021. As it relates to how the referral questions should be answered, the board did not take it into account for this decision.

XII. The appellant's appeal case, in so far as it is relevant for the present decision, can be summarised as follows.

Admittance of D23

- D23 was filed in view of the surprising course of events before the opposition division, i.e. the change in relevance attributed to D9 and D10, and in response to the respondent's documents D21 and D22. After the opposition division's preliminary opinion, which was in favour of the appellant, the respondent filed D22 and expressed criticism only about two months before the oral proceedings. In view of the complexity of the experiments, the remaining time period would have been too short to provide further experimental evidence. D22 was intended, inter alia, to challenge the appellant's results in D9 and D10. The appellant should be given the possibility to react to the late filing of D22. Hence, D23 should be admitted into the proceedings.

Admittance of figures 1 and 2 shown in the statement of grounds of appeal as well as the discussion relating to them

- Figures 1 and 2 shown in the statement of grounds of appeal merely amounted to a graphic presentation of the data contained in D9. No new information was added, neither in these figures nor in the discussion relating to them. The respondent had also not identified any such new information.

Admittance of D24

- The respondent's justification for filing D24 only one month before the oral proceedings before the board was not convincing. In the case at hand, there were no "exceptional circumstances, which have been justified with cogent reasons" as required by Article 13(2) RPBA 2020. Hence, D24 should not be admitted into the proceedings.

Sufficiency of disclosure

- The patent in suit did not contain any indication which allowed the skilled person to determine which of the very many claimed combinations, in which ratios, or on which crops and against which pests, might show a synergistic effect. Finding the appropriate conditions amounted to an undue burden for the skilled person. Hence, the invention as stipulated in the claims of the patent in suit as granted was not sufficiently disclosed.

Novelty

- The subject-matter of claim 1 was not novel over D8; that of claims 1 to 3 was not novel over D4. Novelty could also not be acknowledged because the selections, if there were any, were not purposeful.

Inventive step

- D4 was the closest prior art. Of the examples contained in the patent in suit, only test examples 2 and 5 related to insecticide compositions according to claim 1. The appellant's data in D23 showed that the combination of thiamethoxam with chlorantraniliprole did not act synergistically at certain weight ratios against the same and a very similar insect species as those used in the patent in suit. The data in D23 were reliable and should be taken into account. The board correctly found that the respondent's defence, that the data of D23 were unreliable because similar concentrations of insecticides resulted in very different death rates, was not convincing. Additional untreated food was simply added to avoid the premature death of insects from starvation. Not adding additional untreated food would have falsified the results. It could also not be held against the appellant that it had used a different spreading agent in D23 from that of the patent in suit since claim 1 was not limited in this respect. Furthermore, with test examples 2 and 5, the patent in suit contained only two isolated data points. They could not render the synergistic effect plausible over the entire breadth of claim 1. Thus, according to established case law of the boards, the post-published evidence, i.e. D21 and D22, had to be disregarded. Even if D21 and its result against Chilo suppressalis under point 4 were taken into account, such a single experiment could not render a synergistic effect plausible against this insect species over the entire breadth of claim 1. This was because formula Ia covered more than 10 million compounds. The objective technical problem could only be seen as the provision of an alternative insecticide composition. The solution to this problem was rendered obvious by D4, which suggested the combination of thiamethoxam and compounds according to formula Ia.

XIII. The respondent's appeal case, in so far as it is relevant for the present decision, can be summarised as follows.

Admittance of D23

- The defectiveness of D9 and D10 should have been clear to the appellant upon filing. In any event, the respondent had criticised the data in D9 and D10 in its letter of 11 September 2017, and there was no reason why D23 could and should not have been filed earlier. The opposition division would have acknowledged an inventive step even without D22. The filing of D23 could therefore not be considered a reaction to the filing of D22. Also in view of the reasoning given in decision T 101/87, D23 should not be admitted into the proceedings.

Admittance of figures 1 and 2 shown in the statement of grounds of appeal as well as the discussion relating to them

- Figures 1 and 2 shown in the statement of grounds of appeal as well as the discussion relating to them could and should have been filed before the opposition division. They contained new information which had not been on file. They should not be admitted into the proceedings.

Admittance of D24

- The reason for filing D24 was that the board's preliminary opinion had raised, for the first time in the proceedings, issues concerning inventive step which had only been mentioned in the background section of the statement of grounds of appeal. For the respondent, it was completely unclear what purpose this background section should have. D24 should therefore be admitted into the proceedings.

Sufficiency of disclosure

- The opposition division correctly concluded that the invention set out in the claims of the patent in suit as granted was sufficiently disclosed.

Novelty

- The opposition division correctly acknowledged novelty of the claimed subject-matter of the patent in suit as granted over D8 and D4.

Inventive step

- The subject-matter of claim 1 of the patent in suit as granted differed from the closest prior art D4 in that at least two selections had to be made to arrive at the subject-matter of claim 1. The effect linked to these distinguishing features was the synergistic interaction between thiamethoxam and the compounds of formula Ia. This was evident from test examples 2 and 5 in the patent in suit. There was no scientific reason to doubt this effect. It was therefore up to the appellant to prove that the effect was not achieved over the full breadth of the claim. The appellant's documents D9, D10 and D23 were insufficient to provide such proof. More specifically, the appellant's data in D23 were not reliable and should not be taken into account. In D23, the method of the patent in suit was modified in that additional untreated food was added during the test period. Furthermore, D23 showed that similar concentrations of insecticides resulted in very different death rates. Lastly, D23 used a different spreading agent from the patent in suit.

- There was no legal basis for the concept of "plausibility" relied on by the appellant. Even if an ab-initio plausibility criterion were applied, post-published documents D21 and D22 had to be taken into account because the experimental data in the patent in suit had made the synergistic effect plausible. The data in D21 and D22 showed that the synergistic effect was achieved over the whole breadth of claim 1.

- More specifically, D21 showed that thiamethoxam and a compound according to formula Ia acted synergistically against Chilo suppressalis. The appellant had neither challenged this result nor provided appropriate counter-evidence. There was no scientific reason why this synergistic effect should not also be achieved with other insecticide combinations according to claim 1. After all, formula Ia only covered compounds which were very similar from a chemical point of view.

- Therefore, the objective technical problem had at least to be seen as the provision of an insecticide combination whose insecticides acted synergistically against Chilo suppressalis. The solution to this problem was not obvious because synergism per se was unpredictable.

- Even if the objective technical problem was the provision of an alternative, the solution of the patent in suit was not obvious.

Reasons for the Decision

The invention

1. The claimed subject-matter

1.1 The patent in suit as granted comprises two sets of claims for different contracting states, i.e.:

- a set of claims for the contracting states IS and LT

- a set of claims for the contracting states AT, BE, CH, DE, DK, ES, FR, GB, GR, IT, LI, LU, MC, NL and SE

1.2 Claim 1 of the set of claims for the contracting states IS and LT reads as follows:

"An insecticide composition which comprises thiamethoxam and one or not less than two kinds of compounds being selected from a compound represented by the formula [Ia]:

FORMULA/TABLE/GRAPHIC

wherein R1 is a halogen atom or a C1-6 haloalkyl group, R2 is a halogen atom, R3 and R5 each are a C1-6 alkyl group, R4 is a hydrogen or halogen atom, and X is N, or a salt thereof."

1.3 Claim 1 of the set of claims for the contracting states AT, BE, CH, DE, DK, ES, FR, GB, GR, IT, LI, LU, MC, NL and SE comprises the wording of the above claim 1 and the following proviso:

"with the provisio [sic] that the following compounds are excluded

FORMULA/TABLE/GRAPHIC

and

FORMULA/TABLE/GRAPHIC"

1.4 The respective claims 1 of both sets of claims thus only differ from each other in that claim 1 for the contracting states AT, BE, CH, DE, DK, ES, FR, GB, GR, IT, LI, LU, MC, NL and SE additionally contains a disclaimer. This disclaimer excludes compositions which comprise thiamethoxam and at least one of the three specific compounds mentioned which fall within the general definition of formula Ia.

In the following, reference is made to 'the set of claims' or, for example, to 'claim 1' if the argument applies equally to both sets of claims or to claim 1 of both sets.

2. Background of the invention

2.1 The patent in suit (paragraphs [0002] to [0004]) acknowledges, by reference to previously published patent documents, that both thiamethoxam and the compounds according to formula Ia were known for their insecticidal activity before the priority date of the patent in suit. According to the patent in suit (paragraph [0008]), the inventors have found that mixtures of thiamethoxam and compounds according to formula Ia can produce an insecticidal activity which is greater than that which would have been expected based on their respective individual activities. This means that according to the patent in suit, an insecticide composition according to claim 1 can exhibit an over-additive, i.e. synergistic, effect.

2.2 To clarify whether a certain combination of insecticides acts synergistically, the patent in suit first determines the activities of the individual insecticides, where the activity is the death rate, i.e. the percentage of dead insects, observed when a certain number of insects is exposed to a certain amount of insecticide for a certain period of time. From these individual activities, an expected activity for the joint use of both insecticides is calculated using Colby's equation. This expected activity value corresponds to a purely additive effect of both insecticides. If the actually determined activity of the combination of both insecticides is above this expected value, the insecticides act synergistically together. If it is below this value, the insecticides of the combination act antagonistically. The use of this approach to assess the presence/absence of synergism between insecticides was undisputed between the parties.

2.3 The patent in suit (paragraph [0058]) contains a list of examples of insect pests which can be controlled with the above compositions. Among the insect pests mentioned are Spodoptera litura, Plutella xylostella and Chilo suppressalis (for further details, see below under inventive step).

Admittance of D23

3. D23 was filed with the appellant's statement of grounds of appeal to show that thiamethoxam and chlorantraniliprole, i.e. a compound according to formula Ia of claim 1 (R**(1) = Br, R**(2) = Cl, R**(3) = Me, R**(4) = Cl, R**(5) = Me), do not act synergistically against Spodoptera littoralis and Plutella xylostella at certain weight ratios. The respondent requested that D23 not be admitted into the proceedings.

4. In respect of the admittance of D23, the history of the case has to be taken into account.

4.1 With its notice of opposition, the appellant filed D9 and D10. These two experimental reports were intended to show that the combination of thiamethoxam and chlorantraniliprole does not or at least does not always act synergistically. D9 reports on field trials, and the insects tested included the two tested in the patent in suit, i.e. Spodoptera litura and Plutella xylostella.

The respondent criticised the data in D9 in its reply to the notice of opposition and argued that the appellant's data could not be relied upon.

Subsequently, the opposition division in the annex to the summons to oral proceedings accepted the appellant's line of reasoning based on D9 and D10 and concluded "that the experimental data of reports D9 and D10 show, that the technical effect (synergism) is not achieved over the whole scope of claim 1" (page 17, penultimate paragraph).

The respondent criticised the content of both D9 and D10 again in its subsequent submissions dated 11 September 2017 and 27 September 2017, and with the first of these submissions filed a set of experimental data as D22. These data were intended to show, inter alia, that thiamethoxam acts synergistically with chlorantraniliprole, thus challenging the appellant's findings in D9 and D10.

At the oral hearing, the opposition division admitted D22 into the proceedings and, taking it into account, accepted synergism to be a technical effect of the claimed combinations of insecticides.

4.2 While it is true that, as argued by the respondent before the board, the respondent had criticised the content of both D9 and D10 in its submissions dated 11 September 2017 and 27 September 2017, the board does not see why - in view of the opposition division's preliminary opinion in favour of the appellant - this should have necessarily prompted the appellant to file a new set of experimental data.

Furthermore, the board accepts the appellant's argument that experiments which would be suitable in the current context take a certain period of time. They deal with living insects, have to be repeated a number of times for statistical reasons and require a certain lead time, adding to the overall complexity of such experiments. Thus, even if the respondent's criticism in its submissions filed after the opposition division's preliminary opinion had been such that the alleged defectiveness of the appellant's data in D9 and D10 had been immediately clear, it would have been unreasonable to expect the appellant to submit a new set of experimental data given that after the respondent's submissions of 11 September 2017 and 27 September 2017 there remained only about two months until the oral proceedings before the opposition division on 28 November 2017.

In addition, the respondent's submission of 11 September 2017 contained new experimental data D22. It was on the basis of, inter alia, these late-filed additional experimental data that the opposition division changed its mind compared to its previously issued preliminary opinion. Reference is made in this respect to the first paragraph under the heading "Technical effect:" on page 23 of the decision: "The result of test example 2 of the patent in suit and the results of the documents D21 and D22 prove synergism as effect from combining thiamethoxam with compounds falling under formula [Ia] of claim 1."

4.3 In view of the above, the appellant's filing of D23, which addresses the same combination of insecticides as the appellant's previous submissions D9 and D10, is to be considered a legitimate and timely reaction to the:

- change of the opposition division's assessment of D9 and D10 at the oral hearing and in its written decision compared to that in its preliminary opinion

- respondent's filing of D22 only shortly before the oral proceedings before the opposition division

5. The respondent argued that D23 should not be admitted in view of the reasoning given in decision T 101/87. However, in the case underlying that decision, the appellant relied exclusively on documents newly filed with its statement of grounds of appeal and a prior use based on them. These documents bore little relation to those filed in the original opposition (T 101/87: points IV, 2 and 6). In the board's judgement, this decision relates to an entirely different situation and has no bearing on the case at issue.

6. Due to the reasons given above, the board decided to admit D23 into the appeal proceedings pursuant to Article 12(4) RPBA 2007 (being applicable pursuant to Article 25(1) and (2) RPBA 2020).

Admittance of figures 1 and 2 shown in the statement of grounds of appeal as well as the discussion relating to them

7. As stated above, experimental report D9 relates to field trials and was filed with the appellant's notice of opposition. The table in D9 contains combinations of different amounts of thiamethoxam and chlorantraniliprole and the results obtained when applied against different insect species. In addition to the individual activities of thiamethoxam and chlorantraniliprole, this table also contains the expected activities calculated using Colby's equation and the activities found during the actual application of the combinations.

In figures 1 and 2 in the statement of grounds of appeal, the observed activity for each combination of thiamethoxam and chlorantraniliprole of D9 is plotted against its expected activity. The respondent requested that these figures and the discussion relating to them not be admitted into the proceedings because they could have been filed in the proceedings before the opposition division and because they contained new information which had not been on file.

In its communication pursuant to Article 15(1) RPBA 2020, the board had set out why it did not find the respondent's arguments convincing, namely because these two figures merely amounted to a graphic presentation of the data in D9 and because, contrary to the respondent's allegation, no new information appeared to have been introduced in and with these figures or the discussion relating to them. When the respondent was asked to comment at the oral proceedings before the board, it merely referred to its written submissions. The board therefore saw no reason to deviate from its preliminary view and decided to admit figures 1 and 2 shown in the statement of grounds of appeal and the discussion relating to them into the proceedings pursuant to Article 12(4) RPBA 2007 (being applicable pursuant to Article 25(1) and (2) RPBA 2020).

Admittance of D24

8. D24 is a document published after the priority and filing dates of the patent in suit describing the discovery of the insecticide class of anthranilic diamides (i.e. the class to which the insecticides of formula Ia in claim 1 belong) and the development of two specific members of this class, namely chlorantraniliprole and cyantraniliprole. The appellant requested that D24 not be admitted.

8.1 The respondent argued that D24 had been filed in response to the board's communication pursuant to Article 15(1) RPBA 2020. In it, the question of whether a technical effect was achieved over the entire breadth of the claims of the patent in suit as granted had been identified as an issue which possibly had to be discussed with regard to inventive step. In the respondent's view, this was a new issue brought up for the first time in the board's communication, and the filing of D24 was a reaction to this. This was not changed by the fact that this issue had been mentioned in the statement of grounds of appeal. More specifically, this issue was addressed only in the background section of the statement of grounds of appeal, without specifying the link to the actual grounds of appeal. The respondent could not have been expected to identify potential issues mentioned only in this background section. D24 should therefore be admitted into the proceedings.

8.2 D24 was filed by the respondent with the letter of 22 June 2021, i.e. after notification of the summons to oral proceedings (the receipt of the notification had been acknowledged by the respondent by fax on 29 September 2020), which took place after the entry into force of the new Rules of Procedure of the Boards of Appeal. Under these circumstances "[a]ny amendment to a party's appeal case made ... shall, in principle, not be taken into account unless there are exceptional circumstances, which have been justified with cogent reasons by the party concerned." (Articles 25(1) and (3) and 13(2) RPBA 2020). The filing of an entirely new document, such as D24, amounts to an amendment of the respondent's appeal case. As explained in the following, the reasons given by the respondent for submitting D24 only with the letter dated 22 June 2021 are not convincing and for this reason alone cannot satisfy the requirement of Article 13(2) RPBA 2020, in accordance with which there have to be "exceptional circumstances, which have been justified with cogent reasons".

As set out above, D24 had been filed to address whether a technical effect was achieved over the entire breadth of the claims of the patent in suit as granted. As correctly noted by the respondent, the breadth of the claims of the patent in suit is addressed in the background section of the statement of grounds of appeal. For instance, under point 9, reference is made to the broad Markush formula Ia and, with reference to Annex 1, it is stated that it comprised at least ten million compounds. However, at the same time, the breadth of this Markush formula is again addressed in subsequent parts of the statement of grounds of appeal. For example, under point 60, reference is made to the number of combinations covered by the Markush claim, and it is explained that because of this the synergistic effect was not plausible for all claimed combinations of insecticides. Contrary to the respondent's assertion, there is thus a clear link between the background section and the subsequent parts in the statement of grounds of appeal, and there can be no doubt that this issue was clearly raised by the appellant. The board's communication reiterating this issue thus does not constitute an exceptional circumstance within the meaning of Article 13(2) RPBA 2020.

8.3 The board therefore decided not to admit D24 into the proceedings.

Main request (patent in suit as granted)

9. Sufficiency of disclosure (Article 100(b) EPC)

The appellant essentially argued that the patent in suit did not contain any indication which allowed the skilled person to determine which of the very many claimed combinations of compounds, in which ratios, or on which crops and against which pests, might show a synergistic effect. Consequently, the skilled person had to carry out random experiments in the dark and to test and re-test different combinations of known ingredients over and over again until they happened to come across a ratio of specific ingredients which showed synergy. Such a research project clearly amounted to an undue burden.

This is not convincing. As correctly set out in the decision under appeal, synergism is not a feature of the claims of the patent in suit. Consequently, whether this effect is achieved over the entire breadth of the claims is not to be assessed under Article 100(b) EPC but Article 56 EPC (G 1/03 (OJ 2004, 413), point 2.5.2 of the Reasons).

10. Novelty (Article 54 EPC)

The appellant maintained its novelty objections from the proceedings before the opposition division based on D8 (against claim 1) and D4 (against claims 1 to 3).

10.1 Novelty objection based on D8

10.1.1 D8 was published on 2 June 2005 and thus after the filing date of the patent in suit (21 February 2005). Compared to the European patent application/the European patent (published as EP 1 686 857) emanating from D8, the patent in suit additionally designates IS and LT. Therefore, D8 is:

- not prior art for the set of claims for the contracting states IS and LT (see the Decision of the Administrative Council of 28 June 2001 on the transitional provisions under Article 7 of the Act revising the European Patent Convention of 29 November 2000, Article 1, No 1 in connection with Article 54(4) EPC 1973, Article 158(1) and (2) EPC 1973, and Rule 107(1)(d) EPC 1973)

- prior art pursuant to Article 54(3) EPC for the set of claims for the contracting states AT, BE, CH, DE, DK, ES, FR, GB, GR, IT, LI, LU, MC, NL and SE (see, however, point 10.1.4 below)

10.1.2 D8 (claims 1 and 4) discloses an agent containing a synergistically active combination of compounds of formula I and II-1. D8 (page 9, lines 5 to 6) also discloses that six specific compounds according to formula I are particularly preferred. Among these compounds is compound Ig, which is thiamethoxam as referred to in claim 1 of the patent in suit.

The appellant argued that there was a very significant overlap between formula II-1 in D8 and formula Ia in claim 1 of the patent in suit and further that thiamethoxam was a member of a very small group of only six compounds preferably used together with the compounds of formula II-1. The subject-matter of claim 1 of the patent in suit was therefore not novel over D8.

10.1.3 This is not convincing. As regards thiamethoxam, a first selection from a list of six compounds is necessary to get to claim 1 of the patent in suit. Furthermore, formula II-1 is defined in D8 in claim 4 and on page 13, line 35 to page 14, line 31. However, even in its most preferred and restricted definition (page 14, lines 24 to 31), formula II-1 merely overlaps in scope with formula Ia of claim 1 of the patent in suit so that parts of formula II-1 do not fall under the definition of formula Ia. E.g. formula II-1 allows:

- R**(2)/R**(3) to be CH3 and C1-4-alkyl

- R**(4) to be CF3, OCF3, F, Cl, Br or I

- R**(5) to be CF3 or OCF3

- R**(9) to be OCF2H or OCH2CF3

These options are not provided for in formula Ia (see the definitions of NHR**(5), R**(3), R**(4) and R**(1), respectively). Thus, a further (i.e. a second) selection is necessary to get to claim 1 of the patent in suit.

It is established case law of the boards that such a double selection from a prior-art document generates novel subject-matter unless a pointer exists in the prior-art document to the double selection. In the case at hand, no such pointer is present. D8 does not disclose that thiamethoxam is preferred among the six compounds mentioned on page 9, lines 5 to 6. Furthermore, there is no indication in D8 that the overlap of formula II-1 and Ia (or an even smaller part of the overlap) would be generally preferred.

Contrary to the appellant's argument, the reasoning of T 12/90 does not contradict the above conclusion as this decision concerns overlapping Markush formulae only. In this case, however, there are not only the overlapping Markush formulae II-1 and Ia, but there is an additional list of six compounds from which one must be selected.

10.1.4 Furthermore, the filing date of D8 is after the priority dates of the patent in suit. The appellant did not contest the validity of the priority claim of the patent in suit, and the board does not see a reason why it should not be valid. This means that subject-matter disclosed in D8 can only be novelty-destroying if it is also contained in one of its two priority applications D8P1 and/or D8P2 (in the appellant's favour, this was assumed to be the case for the passages of D8 referred to above).

D8 also gives a list of preferred compounds of formula II-1 on pages 15 to 17. Of these, however, only II-1-1 to II-1-16 are disclosed in D8P1 (table on pages 16 and 17) and D8P2 (table on pages 16 and 17), and only six (II-1-1, II-1-3, II-1-4, II-1-9, II-1-11 and II-1-12) are according to formula Ia in claim 1 of the patent in suit, speaking again to the fact that there is no pointer to the (second) selection. D8 (pages 21 to 27) also discloses preferred combinations of compounds of formula I and II-1. However, only very few combinations are combinations of thiamethoxam and a compound of formula Ia in the patent in suit. Of these very few combinations, only three are disclosed in D8P1 (page 17, line 8 to page 18, line 28) and D8P2 (page 17, line 8 to page 18, line 28):

Ig and II-1-9

Ig and II-1-11

Ig and II-1-12

However, these combinations are disclaimed from the subject-matter of claim 1 of the set of claims for the contracting states AT, BE, CH, DE, DK, ES, FR, GB, GR, IT, LI, LU, MC, NL and SE. Furthermore, as set out above (point 10.1.1), D8 is not prior art for the set of claims in the remaining two contracting states IS and LT.

10.2 Novelty objection based on D4 (prior art pursuant to Article 54(2) EPC)

10.2.1 The line of argument put forward by the appellant based on D4 was very similar to that based on D8.

The appellant argued that D4 (claim 1) disclosed a broad Markush formula 1 which overlapped to a great extent with formula Ia in claim 1 of the patent in suit. D4 also disclosed compositions comprising a compound of formula 1 and one additional biologically active compound such as thiamethoxam (page 59, lines 9 to 27). Thus, D4 was novelty-destroying for the subject-matter of claims 1 to 3 of the patent in suit, it argued.

10.2.2 Similar to the arguments relating to D8, this is again not convincing. In D4 (page 59, lines 12 ff., in particular line 27; claim 12), thiamethoxam is only disclosed in a long list of possible additional biologically active compounds. D4 does not disclose that thiamethoxam is preferred. Formula 1 is defined in D4 in claim 1. Similar to D8, formula 1 of D4 merely overlaps in scope with formula Ia of claim 1 of the patent in suit so that parts of formula 1 do not fall under the definition of formula Ia. For instance, formula 1 allows:

- R**(1) to be F, Cl or Br

- R**(2) to be CF3

- R**(3) to be OCH2CF3

- R**(4a)/R**(4b) to be CH3 and C1-4-alkyl

These options are not provided for in formula Ia (see the definitions of R**(3), R**(4), R**(1) and NHR**(5), respectively). There is no indication in D4 that the overlap of formula 1 and Ia (or an even smaller part of the overlap) would be generally preferred. Of the compounds listed in table 1 (pages 37 ff.) and table A (pages 63 ff.) according to formula 1, only a small fraction of them fall under the definition of formula Ia. D4 also discloses more limited lists of 16 preferred compounds according to formula 1 (page 4, line 30 to page 5, line 26; claim 8). However, the last four compounds in these lists do not fall under the definition of formula Ia. Thus, a second selection is again necessary to get to claim 1 of the patent in suit.

10.3 In its letter of 19 April 2021, the appellant further argued that the respective selections from D8 and D4, if there were any, had to be purposeful for the acknowledgement of novelty. The appellant noted that the third criterion of the three-part test for assessing novelty of a numerical sub-range selected from a broader range was no longer applied by the majority of boards. However, in the appellant's view, this was wrong. In this context, the appellant, with its subsequent letter of 22 April 2021, submitted a correspondence between epi and the President of the European Patent Office.

As correctly set out by the appellant, the "purposeful selection" criterion was developed with respect to a selection of a narrower numerical range from a broader range. The case law is therefore not applicable to the case at hand which is not related to numerical ranges and furthermore concerns a double selection namely (i) from a longer list of compounds and (ii) from a set of compounds defined in the form of a Markush formula. The appellant's argument is thus not convincing.

10.4 Thus, the subject-matter of claim 1 is novel over D8, and furthermore the subject-matter of claim 1 and consequently also of its dependent claims 2 and 3 is novel over D4. The decision under appeal is therefore also confirmed on this point.

11. Referral - Introduction

11.1 After acknowledgement of sufficiency of disclosure and novelty, the next point to be assessed was inventive step. During this assessment, it turned out that questions needed to be referred to the Enlarged Board of Appeal on whether evidence not public before the filing date of the patent in suit and filed after that date ("post-published evidence") can be taken into consideration in view of the plausibility case law of the boards.

11.2 For a referral to be admissible, it is generally considered necessary that the decision on the referral questions be decisive for the outcome of the referral case.

As is clear from the above, the appellant's objections as regards sufficiency and novelty were not successful. Whether an inventive step can be acknowledged will therefore be decisive for the outcome of this case.

For inventive step, the respondent relied on, inter alia, post-published evidence D21 in support of a synergistic effect. In view of the parties' different positions on the applicability of the plausibility case law, both formulated opposing requests as to whether post-published evidence D21 should be taken into consideration.

11.3 The board assessed whether D21 is relevant for inventive step because only if it is does the answer to whether post-published evidence such as D21 can be taken into consideration matters for inventive step and thus the outcome of the case.

The board notes that the appellant also relied on post-published evidence for inventive step, namely D23. After the board had decided to admit D23 on procedural grounds (see above), the respondent did not question that D23 could be taken into account. D23 was therefore taken into consideration in the board's assessment of inventive step. However, the board is aware and pointed out during the oral proceedings that D23 is post-published evidence and that it cannot be excluded that after the decision of the Enlarged Board of Appeal, the question of whether D23 can be taken into consideration might have to be re-assessed.

12. Relevance of post-published evidence D21 for inventive step

12.1 As set out above, it was examined whether post-published evidence D21 is relevant for inventive step. The board therefore used the problem-solution approach without (point 12.4) and with D21 (point 12.5) to answer this question.

12.2 Both parties agreed that D4 was the closest prior art. The board saw no reason to deviate from this unanimous view.

12.3 Based on the assessment above with respect to novelty over D4 and in line with the decision under appeal, the subject-matter of claim 1 of the patent in suit is distinguished over D4 in that both thiamethoxam and the compounds according to formula Ia have to be selected from the respective broader teachings of D4.

12.4 Problem-solution approach without D21

With regard to a technical effect linked to the distinguishing features, the respondent relied on a synergistic effect resulting from the claimed combination of compounds and referred to test examples 2 and 5 of the patent in suit.

12.4.1 Test examples 2 and 5 of the patent in suit are the only examples in which insecticide compositions according to claim 1 are tested against different insect species. Test example 2 shows that the combination of thiamethoxam with compound I-1 (in formula Ia: R**(1) = CF3, R**(2) = Cl, R**(3) = Me, R**(4) = H, R**(5) = i-Pr) acts synergistically against Spodoptera litura when both insecticides are used at a weight ratio of 1:1. Similarly, test example 5 shows that the combination of thiamethoxam with compound I-4 (in formula Ia: R**(1) = Cl, R**(2) = Cl, R**(3) = Me, R**(4) = Cl, R**(5) = i-Pr) acts synergistically against Plutella xylostella when both insecticides are used at a weight ratio of 1:1.

12.4.2 Thus, the question to be answered is whether test examples 2 and 5 of the patent in suit provide a valid proof that the claimed subject-matter results in a synergistic effect at least against Spodoptera litura and Plutella xylostella. If this is the case, the objective technical problem could be formulated as the provision of an insecticide composition which acts synergistically against Spodoptera litura and Plutella xylostella.

12.4.3 The appellant did not challenge these results of the patent in suit. However, it referred to its tests described in D23. As stated above, D23 serves to show that the combination of thiamethoxam and chlorantraniliprole, i.e. a compound which falls under formula Ia of claim 1 but which is different from those used in test examples 2 and 5, does not act synergistically against Spodoptera littoralis and Plutella xylostella at certain weight ratios.

12.4.4 The respondent argued that in view of the differences between D23 and the test examples of the patent in suit, the results in D23 had no bearing on the relevance of these test examples. The board does not agree with this argument.

The two relevant examples of D23 are examples 5 and 6. The species used in example 6 of D23 (Plutella xylostella) is the same as that used in test example 5 of the patent in suit. The species used in example 5 of D23 (Spodoptera littoralis) is different from test example 2 of the patent in suit (Spodoptera litura). However, the appellant stated that Spodoptera littoralis was closely related to Spodoptera litura and that therefore the same results had to be expected when the insecticide combinations of example 5 of D23 were used against Spodoptera litura. This was not disputed by the respondent, and the board sees no reason to doubt the appellant's statement.

Furthermore, as argued by the appellant, the general procedure used in D23 was essentially analogous to that described in the patent in suit. The insects were exposed to plant parts treated with an insecticide or a combination of insecticides. After a certain exposure time, the activity of the insecticide(s) (i.e. the death rate) was determined.

This procedure had to be modified in the experiments with Spodoptera littoralis in that further untreated plant parts were added after the treated plant parts had been completely consumed by the insects. However, this only served to prevent the premature death of the insects through starvation and thus a falsification of the results, which otherwise would have been due not only to the insecticides but also to a lack of food.

Lastly, in the test compositions of D23, the appellant used a spreading agent different from the ones used in test examples 2 and 5 of the patent in suit. However, the composition of claim 1 is not limited in this respect and essentially allows any spreading agent to be contained in it.

Contrary to the respondent's arguments, the appellant's modifications of the method of the patent in suit cannot therefore call into question the validity of the experiments in D23.

12.4.5 In D23, dose-response experiments were first carried out to determine suitable concentration ranges of thiamethoxam and chlorantraniliprole for the actual synergy experiments. As set out above, the actual synergy experiments are described in examples 5 and 6 of D23. In these synergy experiments, the activities of the two insecticides thiamethoxam and chlorantraniliprole were initially determined individually again. It may be that, as argued by the respondent, some of the individual activities determined for thiamethoxam or chlorantraniliprole in the dose-response experiments are different from those determined in examples 5 and 6. However, in the board's view, this cannot call into question the validity of the results described in examples 5 and 6 since (i) experiments with living organisms are naturally subject to fluctuations and deviations between different series of experiments are therefore not unusual and (ii) the activities described for the individual insecticides in examples 5 and 6 follow a clear trend, namely towards lower activity with a decreasing amount of insecticide. Because the respondent's defence relating to this alleged lack of reliability was not convincing, there was no need at the oral proceedings to decide on the appellant's request that it not be admitted into the proceedings. In summary, the board considers the results described in examples 5 and 6 of D23 valid.

12.4.6 In example 5 of D23, the effect of the combination of thiamethoxam and chlorantraniliprole against Spodoptera littoralis was determined at 25 different weight ratios in a range from 3840:1 to 15:1 (thiamethoxam:chlor-antraniliprole). In example 6, the effect of the same combination was determined against Plutella xylostella, at 25 different weight ratios, in a range from 16000:1 to 62.5:1.

As can be seen from the tables in examples 5 and 6 of D23, in both cases thiamethoxam and chlorantraniliprole do not act synergistically at all weight ratios, on the contrary, they even clearly act antagonistically at some weight ratios. For example, while the expected death rate in experiment 6 at a weight ratio of 100:0.0125 (thiamethoxam:chlor-antraniliprole) was 62%, the observed death rate was only 14%. For the two specific species, it is not possible to make out a clear tendency towards synergy over the tested range of weight ratios.

Since claim 1 is not limited to compounds I-1 and I-4 used in test examples 2 and 5 and/or their weight ratios to thiamethoxam, the combinations of insecticides with their weight ratios tested in D23 also fall within the subject matter of claim 1. Therefore, it can be concluded that the synergistic effect described in the patent in suit for Plutella xylostella and Spodoptera litura is not achieved over the entire breadth of claim 1.

12.4.7 Thus, given only the experimental data in the patent in suit and in light of D23, the objective technical problem would have to be formulated less ambitiously as the provision of an alternative insecticide composition.

12.4.8 D4 discloses the insecticidal activity of both thiamethoxam and compounds according to formula Ia in claim 1. Moreover, the patent in suit itself acknowledges that their insecticidal activities were known before the priority date of the patent in suit (see above). However, arbitrarily combining compounds known to have insecticidal activity to achieve an alternative insecticide composition does not require an inventive step.

12.4.9 Thus, without D21, i.e. solely in view of the experimental data in the patent in suit and in light of D23, the main request would not be allowable.

12.5 Problem-solution approach with D21

Whether this conclusion changes when D21 is taken into consideration is examined below.

12.5.1 The respondent referred to D21, example 4. This example deals with a different species from that used in test examples 2 and 5 of the patent in suit or in D23. Example 4 shows that thiamethoxam and compound I-1, i.e. a compound according to formula Ia of claim 1, at a weight ratio of 1:8, act synergistically against the insect species Chilo suppressalis. It was a matter of dispute between the parties whether in view of this the objective technical problem could be formulated as the provision of an insecticide composition that acts synergistically against Chilo suppressalis.

The result in example 4 of D21 in itself was not challenged by the appellant, which also did not present any counter-evidence regarding this species in D9, D10 or D23 that could call the result into question.

However, the appellant argued that this isolated example of D21 was not a valid proof of a synergistic effect against Chilo suppressalis for all insecticide compositions covered by claim 1. That was because, according to the appellant's conservative calculations in Annex 1, formula Ia covered over 10 million compounds.

The board does not agree. In view of the data in D21 and in the absence of any counter-evidence from the appellant, the board sees no reason not to acknowledge this synergistic effect against Chilo suppressalis also for other insecticide compositions covered by claim 1, i.e. insecticide compositions comprising thiamethoxam and a compound of formula Ia different from compound I-1.

This position is further supported by the fact that the variability of formula Ia is quite limited in chemical terms. All compounds are based on the same characteristic core structure, namely an anthranilic acid amide part acylated with a (pyridin-2-yl)-1H-pyrazole-5-carboxylic acid. Groups R1 to R5 allow for different substituents, in particular alkyl and haloalkyl groups. According to the appellant's calculations in Annex 1, the number of compounds covered by formula Ia is very high precisely because of these alkyl and haloalkyl groups. However, the compounds of formula Ia and in particular the compounds of formula Ia with different alkyl or haloalkyl groups are, at least in the board's view, not so chemically different that a different behaviour would necessarily be expected in combination with thiamethoxam.

Therefore, the synergistic effect observed in example 4 of D21 against the insect species Chilo suppressalis can be acknowledged to be achieved over the entire breadth of claim 1 provided D21 can be taken into account.

12.5.2 Given the post-published data in D21 and in line with the respondent's arguments, the objective technical problem would have to be formulated as the provision of an insecticide composition in which the insecticides act synergistically against Chilo suppressalis. As explained during the oral proceedings, the board does not take issue with the formulation of this more specific objective technical problem which also includes a specific insect species. This is because it would be technically nonsensical to require synergism against each and every insect species (for a similar view, albeit with regard to sufficiency, see T 1326/08, point 4.2.2 of the Reasons). The respondent did also not object to the formulation of this objective technical problem.

12.5.3 The appellant only ever argued that the objective technical problem lay in providing an alternative insecticide composition. It never addressed obviousness on the basis of the above more ambitious objective technical problem. In fact, the skilled person confronted with the above more ambitious technical problem would not have found any suggestion in the prior art to arrive at the claimed subject-matter. For that reason alone, an inventive step would have to be acknowledged, provided D21 can be taken into account.

12.6 In summary, the main request would not be allowable if only the data in the patent in suit and D23 could be taken into account. If the post-published data in D21 could also be taken into account, the main request would be allowable. Therefore, the allowability of the main request crucially depends on the question of whether the post-published data in D21, which are the only proof of a synergistic effect against Chilo suppressalis, can be taken into account.

13. Need for the referral questions

13.1 As set out below, whether post-published evidence, such as D21, can be taken into account is a fundamental question of law for which diverging lines of case law exist.

13.2 For the assessment of inventive step, the problem-solution approach is regularly applied by the departments of the EPO (Case Law of the Boards of Appeal of the European Patent Office, 9th edition, 2019 (CLBA), I.D.2). This approach requires, inter alia, that:

- the closest prior art be identified (which may not necessarily be the one mentioned in the patent in suit or envisaged by the patent proprietor)

- a comparison be made between the subject-matter of the claim at issue and the disclosure of the closest prior art and that the difference(s) between both be identified

- the technical effect(s), linked to the difference(s), be determined

- the objective technical problem be formulated, i.e. the problem which can be seen to have actually been solved in light of the closest prior art

In this analysis, it is often necessary, like in this case, to provide post-published evidence (i.e. evidence that was not public before the filing date of the patent in suit and was filed after that date) as proof that the problem has been solved (i.e. that the alleged technical effect is actually achieved). This applies in particular when the objective technical problem has to be reformulated, e.g. with regard to a closest prior-art document previously unknown to the patent proprietor.

Where the proof that a problem has been solved (in this case, the provision of an insecticide composition in which the insecticides act synergistically against Chilo suppressalis) rests on such post-published evidence (in this case, D21), there are, in the board's view, three diverging lines of case law from the boards regarding the circumstances under which the evidence can or cannot be taken into account. The subsequent discussion identifies these different lines of case law.

13.3 Before starting this discussion, the board would like to make the following remarks.

13.3.1 Whether D21 can be taken into account arose in the case at hand in the context of inventive step because the synergistic effect is part of the problem to be solved. In other cases, the same issue, namely whether post-published evidence can be taken into account, arose under the heading of sufficiency of disclosure because the effect was expressed in the claim at issue. While the fact that an effect is part of the problem to be solved or expressed in the claim at issue dictates which provision of the EPC is applicable (G 1/03 (OJ EPO 2004, 413), point 2.5.2 of the Reasons), it does not - at least not in the board's view - have an impact on the considerations applying to the above issue. Therefore, not only decisions dealing with this issue under Article(s) 100(a) and/or 56 EPC but also those dealing with this issue under Article(s) 100(b) and/or 83 EPC are mentioned below.

13.3.2 The following discussion is directed at the question of whether post-published evidence can be taken into account on substantive grounds, depending on the plausibility of the technical effect based on the evidence submitted as proof. This discussion should not be confused with whether post-published evidence can be taken into account on procedural grounds in particular in view of Articles 12 and 13 RPBA. The following discussion is based on the assumption that the post-published evidence in question does form part of the appeal proceedings.

13.4 Ab initio plausibility

In accordance with a first line of case law, post-published evidence can be taken into account only if, given the application as filed and the common general knowledge at the filing date, the skilled person would have had reason to assume the purported technical effect to be achieved. In this line of case law, experimental data or a scientific explanation in the application as filed commonly serve as reasons which justify this assumption. This line of case law applies a standard which is referred to in the following as the "ab initio plausibility" standard. The line of case law applying this standard is denoted in the following as the "ab initio plausibility line of case law".

13.4.1 For example, in T 1329/04, the underlying application as filed related to a new polypeptide (denoted growth differentiation factor-9 (GDF-9)), and stated it to be a new member of the transforming growth factor-beta (TGF-beta) superfamily. One alternative in the claim at issue related to GDF-9. In view of the closest prior art, the problem to be solved was defined as isolating a further member of the TGF-beta superfamily. The board in question noted that GDF-9 did not have the structural features generally accepted for members of the TGF-beta superfamily and that the application as filed did not contain any evidence as to whether the mode of action of GDF-9 permitted assignment to the TGF-beta superfamily. Thus, although the application as filed explicitly set out GDF-9 to be a member of the TGF-beta superfamily, the board concluded (point 11 of the Reasons; emphasis added by the current board):

"that the application does not sufficiently identify this factor as a member of this family i.e. that there is not enough evidence in the application to make at least plausible that a solution was found to the problem which was purportedly solved."

Post-published evidence establishing that GDF-9 was indeed a growth differentiation factor was not taken into account, and the presence of an inventive step was ultimately denied. The board based its conclusion on the following consideration, which was later on applied in several other decisions applying the ab initio plausibility standard (point 10 of the Reasons; emphases in bold and annotation in squared brackets by the current board):

"Hence, it is particularly important [in a first-to-file system] that the application allows to conclude that the invention had been made, i.e. that a problem had indeed been solved, not merely put forward at the filing date of the application. Therefore, the issue here is rather how much weight can be given to speculations in the application in the framework of assessing inventive step ..."

Thus, it seems to have been of crucial importance for the board in T 1329/04 (and the other decisions applying the ab initio plausibility standard) to be able to ensure that the patent applicant was actually in possession of the invention at the time of filing to prevent purely speculative claiming and thus to safeguard a balance between the actual technical contribution and the patent monopoly defined by the claims.

13.4.2 This decision was in line with the earlier decision

T 609/02, in which the board in the context of sufficiency of disclosure reasoned (points 5 to 9 of the Reasons; emphasis added by the current board) that:

"The patent specification provides no evidence at all relating to the invention in claim 6 ... The appellant provided post-published evidence showing that steroid hormones such as needed to carry out the use according to claim 6 were later structurally identified and that they, indeed, have an effect on AP-1 stimulated transcription. ... On the basis of the disclosures of these post-published documents, it was argued by the appellant that by carrying out the claimed invention, one would necessarily obtain pharmaceutical compositions since it was by following the teachings of the patent in suit that the post-published results had been obtained. Consequently, in the appellant's opinion, sufficiency of disclosure had to be acknowledged. The board cannot share this opinion. Sufficiency of disclosure must be satisfied at the effective date of the patent, ie on the basis of the information in the patent application together with the common general knowledge then available to the skilled person. Acknowledging sufficiency of disclosure on the basis of relevant technical information produced only after this date would lead to granting a patent for a technical teaching which was achieved, and, thus, for an invention which was made, at a date later than the effective date of the patent. The general principle that the extent of monopoly conferred by a patent should correspond to, and be justified by, the technical contribution to the art, has to be kept in mind ... It is required that the patent provides some information in the form of, for example, experimental tests, to the avail that the claimed compound has a direct effect on a metabolic mechanism specifically involved in the disease, this mechanism being either known from the prior art or demonstrated in the patent per se. ... Once this evidence is available from the patent application, then post-published (so-called) expert evidence (if any) may be taken into account, but only to back-up the findings in the patent application in relation to the use of the ingredient as a pharmaceutical, and not to establish sufficiency of disclosure on their own."

13.4.3 The ab initio plausibility standard was adopted for example in T 488/16 that reads (point 4.2, 4.5 and 4.19 of the Reasons; emphases added by the current board):

"It is established jurisprudence of the boards of appeal that the assessment of inventive step is to be made at the effective date of the patent on the basis of the information in the patent together with the common general knowledge then available to the skilled person. Post-published evidence in support that the claimed subject-matter solves the technical problem the patent in suit purports to solve may be taken into consideration, if it is already plausible from the disclosure of the patent that the problem is indeed solved (see Case Law of the Boards of Appeal, 8th edition, I.D.4.6; T 1329/04, point 12 of the Reasons; T 1043/10, point 12 or [sic] the Reasons). Thus, for post-published evidence to be taken into account, it is necessary to establish whether or not the asserted activity has been made sufficiently plausible for dasatinib at the effective date of the patent in suit. Basis for this assessment is the application as filed and the common general knowledge of the person skilled in the art at the filing date."

"In the board's judgement, a mere verbal statement that "compounds have been found active" in the absence of any verifiable technical evidence is not sufficient to render it credible that the technical problem the application purports to solve, namely providing PTK inhibitors to treat disorders or diseases associated therewith, is indeed solved ..."

"... the board concurs with the opposition division and the respondents that the post-published documents (9) and (10) are the first disclosure showing that ... the purported technical problem has actually been solved. In accordance with established case law, these documents are therefore not taken into consideration in the assessment of inventive step."

13.4.4 Other decisions in line with the three mentioned above include T 415/11 (points 45 to 55 of the Reasons), T 1791/11 (points 3.2.5 to 3.2.7 of the Reasons) and T 895/13 (points 15 to 17). In the decisions cited in section 13.4, which all apply the ab initio plausibility standard, plausibility was ultimately denied.

13.5 Ab initio implausibility

In accordance with a second line of case law, post-published evidence can only be disregarded if the skilled person would have had legitimate reasons to doubt that the purported technical effect would have been achieved on the filing date of the patent in suit. Such doubts may arise, for example, from the fact that either the application as filed or the common general knowledge on the filing date of the patent in suit give an indication that the purported technical effect can in fact not be achieved. In other words, post-published evidence must always be taken into account if the purported technical effect is not implausible. This line of case law applies a standard referred to in the following as the "ab initio implausibility" standard. The line of case law applying this standard is denoted in the following as the "ab initio implausibility line of case law".

13.5.1 An example of a decision that applies the ab initio implausibility standard is T 919/15, which concerned the use of herbicide combinations for controlling harmful plants ("weeds") in soybean crops, the combination having an active content of two different herbicides (A) and (B). While the application as filed contained experimental proof of a synergistic interaction for some combinations of herbicides falling under the definitions for (A) and (B), the proof of other combinations was submitted only after the filing date. The opponent argued that the synergistic interaction of herbicides was inherently unpredictable and that the application as filed did not make the synergistic effect plausible for the combinations for which only post-published evidence had been submitted. Therefore, the post-published data had to be disregarded for the assessment of inventive step.

The board in question did not agree. It reasoned (point 5.6 of the Reasons; translation provided and emphasis added by the current board):

"Thus, in the absence of evidence to the contrary in the common general knowledge for herbicide combinations containing herbicide (A), it cannot simply be assumed that a synergistic interaction would be per se implausible for the combinations not tested in the application as filed. This conclusion is in line with decision T 863/12, in which the plausibility of an effect was also confirmed on the basis of, inter alia, the fact that the common general knowledge did not contain any indications that could question this plausibility ..."

13.5.2 A further noteworthy example in this context is decision T 578/06. Here, claim 1 of the main request read as follows (emphasis added by the current board):

"[u]se of somatostatin ... in the formulation of a pharmaceutical ... preparation for the treatment of a human patient in receipt of transplanted isolated pancreatic islet cells, wherein the pharmaceutical composition is administered ..., whereby the functional life of the isolated transplanted pancreatic islet cells is extended relative to untreated transplanted isolated pancreatic islet cells."

In the appealed decision, the examining division had come to the conclusion that it was not plausible that the effect of extending the functional life of transplanted pancreatic islet cells could be obtained with the claimed subject-matter. The board, in overturning this decision and acknowledging plausibility of the effect, noted the following (points 13 and 15 of the Reasons; emphases added by the current board):

"The board notes that the EPC requires no experimental proof for patentability and considers that the disclosure of experimental data or results in the application as filed and/or post-published evidence is not always required to establish that the claimed subject-matter solves the objective technical problem. This is in particular true in the absence of any formulated substantiated doubt as is the case here."

"The board re-emphasises in this context however that this case law considers the establishment of plausibility only relevant when examining inventive step if the case at hand allows the substantiation of doubts about the suitability of the claimed invention to solve the technical problem addressed and when it is thus far from straightforward that the claimed invention solves the formulated problem."

After plausibility had been acknowledged, the board took the post-published evidence into account (point 17 of the Reasons).

13.5.3 Further decisions in line with the two above are T 536/07 (point 11 of the Reasons), T 1437/07 (point 38.1 of the Reasons), T 266/10 (point 37 of the Reasons), T 863/12 (point 7.3.3 of the Reasons), T 184/16 (points 2.4 to 2.7 of the Reasons) and T 2015/20 (point 2.7 of the Reasons). In all the decisions cited in section 13.5 applying the ab initio implausibility standard, plausibility was ultimately acknowledged.

13.5.4 The current board acknowledges that some of the decisions discussed above that apply the ab initio implausibility standard contain statements according to which they do not contradict T 1329/04, i.e. a decision considered by the current board to apply the ab initio plausibility standard. This would appear to imply that there is no divergence between the lines of case law applying the ab initio plausibility and the ab initio implausibility standard, respectively. However, close reading reveals that despite these statements, these decisions considered it decisive that there were no indications of doubt or reasons for implausibility on the filing date of the patent in suit (ab initio implausibility standard).

Furthermore, irrespective of whether a divergence is considered to exist, in this board's view at least, it is a fundamental question of law whether the ab initio plausibility or ab initio implausibility standard is to be applied.

13.5.5 The difference between the two lines of case law referred to above cannot be better illustrated than by the judgment of the UK Supreme Court of 14 November 2018, Generics (UK) (trading as Mylan) v. Warner-Lambert Company Ltd ("the UK Supreme Court decision") and the follow-up on this judgment by C. Floyd, "Plausibility: where from and where to", GRUR, 2021, 185. In the case underlying the UK Supreme Court decision, claim 3 at issue referred to the use of pregabalin for the preparation of a pharmaceutical composition for treating neuropathic pain. A central question to be answered was whether it was plausible at the priority date that the therapeutic effect of treating neuropathic pain could be achieved and whether, in view of this, the post-published evidence could be taken into account.

The majority opinion answered this question in the negative. It was held that the experimental data in the application as filed were predictive of efficacy for the treatment of inflammatory pain. But the application as filed did not claim that the experimental data presented made it plausible that pregabalin was effective for the treatment of any kind of neuropathic pain (point 42 of the decision). According to point 52 of the decision, it could:

"... not ... be enough to justify a monopoly that it is "possible" a priori that a drug which was effective for inflammatory pain would also be effective for neuropathic pain, in the absence of any reason to suppose that the possibility had some scientific basis or that it was more than speculative. Everything is possible that is not impossible, but "not impossible" is very far from being an acceptable test for sufficiency. Plausibility may be easy to demonstrate, but it calls for more than that."

So the majority in the UK Supreme Court decision seems to have applied what this board has termed the ab initio plausibility standard.

The minority opinion answered the above question in the positive. According to this opinion, the patent proprietor was not required to demonstrate within its patent a prima facie case of therapeutic efficacy (point 180 of the decision). Furthermore, according to point 181 of the decision (emphasis added by the board), recent decisions of the boards:

"... do not require that the patent discloses experimental evidence to demonstrate that plausibility unless there is an allegation, supported by sufficient evidence, that the invention does not work, ..."

It was also added (point 195 of the decision, emphasis added by the board) that:

"Only if a person skilled in the art would have significant doubts about the workability of the invention would it, in such a case, fail for insufficiency of disclosure."

Hence, the minority in the UK Supreme Court decision seems to have applied what the board has termed the ab initio implausibility standard.

13.6 No plausibility

A third line of case law seems to reject the concept of plausibility altogether. This third line of case law is referred to in the following as applying the "no plausibility" standard. The line of case law applying this standard is denoted in the following as the "no plausibility line of case law".

13.6.1 In T 31/18, the underlying application as filed related to pharmaceutical tablets comprising imatinib or pharmaceutically acceptable salts of it. The claim at issue was essentially directed to a tablet comprising imatinib and cross-linked polyvinylpyrrolidone in certain amounts. In view of the closest prior art, the patent proprietor formulated the problem essentially as the provision of imatinib tablets having a disintegration time of 20 minutes or less, and it also filed experimental evidence to prove that this problem had been solved. According to one of the opponents, this experimental evidence was not to be taken into account as it related to an effect which had not been plausibly shown to be achieved by the claimed tablets in the application as filed. The board held (point 2.5.2 of the Reasons) that:

"This line of argumentation appears to be incompatible with the assessment of inventive step according to the problem solution approach ... It can indeed not be expected from a patent applicant to include an extensive number of experimental evidences corresponding to all technical features which can possibly be claimed in the application as filed and which can possibly constitute a future distinguishing feature over the closest prior art, since said closest prior art and its technical disclosure may not be known to the applicant at the filing date of the application."

The board took the experimental evidence into account but held that it could not support the alleged effect of a low disintegration time vis-à-vis the closest prior art.

13.6.2 A similar decision was taken in T 2371/13. The claim at issue essentially concerned the use of a combination of two particular cationic direct dyes. In view of the closest prior art, the patent proprietor formulated the problem essentially as the provision of dye compositions having improved colour homogeneity. It also filed experimental evidence showing that this effect was achieved for the compositions tested. One of the opponents argued that the effect of an improved homogeneity had not been rendered plausible by the application as filed because the latter did not contain any experimental data in this respect. The effect was speculative and at the date of filing, no invention had been made. The board held (point 6.1.2 of the Reasons and catchword of the decision; translation provided by the current board) that:

"This line of argument is incompatible with the assessment of inventive step according to the problem-solution approach which requires that the state of the art closest to the invention be identified and that a technical problem in relation to that state of the art be formulated which problem is solved by the claimed subject matter. It is usual to invoke a technical effect for inventive step which is not explicitly mentioned in the application as filed."

"A lack of plausibility of an effect based on the absence of evidence in the patent application is not a sufficient reason to disregard comparative tests filed later to prove that effect. Dismissing them for this reason is inconsistent with the problem-solution approach which requires defining a technical problem from the closest prior art document, which is not necessarily the one cited in the patent application - see point 6.1 of the reasons."

The board took the patent proprietor's post-published data into account but considered it as not supportive of the effect over the entire breadth of the claim at issue.

13.7 Further considerations

13.7.1 The three lines of case law discussed above contain two extreme positions, one being a strict application of the ab initio plausibility standard and the other one applying the no plausibility standard. These two extremes illustrate that different results are obtained depending on which plausibility standard is applied. On the one hand, by applying the ab initio plausibility standard strictly, the ultimate result would be that patent applicants receive a patent only for embodiments for which experimental data or other substantiation is contained in the application as filed that makes the effect invoked for inventive step plausible for these embodiments. Hence, any extension of the claimed scope over what has been experimentally shown or otherwise substantiated in the application as filed would lead to refusal of the application. If, on the other hand, no plausibility standard were applied at all, a patent applicant could claim whatever it thinks might possibly be proven later to bring about a purported technical effect. This would give rise to what is often referred to in the case law as "speculative patenting" or "armchair inventions" where a monopoly is conferred to a patent applicant for mere speculation rather than a true invention. The ab initio implausibility standard in terms of its results appears to lie somewhere between these two extreme lines of case law.

13.7.2 On the other hand, requiring plausibility or at least the absence of implausibility to access post-published evidence can be particularly problematic in cases where an effect needs to be established vis-à-vis a prior-art document that has not been, and perhaps could not have been, considered by the patent proprietor/applicant. For instance, if a patent proprietor is confronted with a new closest prior document which makes a reformulation of the objective technical problem necessary, in particular under the ab initio plausibility line of case law, the patent proprietor would be barred from providing any evidence in support of the reformulated technical problem. This would mean a basically insurmountable hurdle for patentability once an opponent invokes a new closest prior-art document in opposition proceedings. Furthermore, such an approach would go against decades of case law which has allowed the reformulation of the technical problem in view of new closest prior-art documents and the reliance on post-published evidence in support of the newly formulated problem. In fact, the only hurdle applied in this case law has been that the newly formulated problem must be within the spirit of the invention as originally disclosed. See, for instance, T 1397/08, where it is stated in the catchword (translation provided and emphasis added by the current board; see also T 184/82 (point 5 of the Reasons)) that:

"According to the problem-solution approach for assessing inventive step in the field of chemistry, the technical problem can be reformulated, and in certain circumstances must even be reformulated, since for the objective determination of the problem, only the result actually achieved in relation to the closest state of the art counts. Nothing prevents, even at the appeal stage, the modification of the problem initially posed, provided that the spirit of the original statement of the invention is preserved ..."

The same follows from decision T 1422/12. In the case underlying that decision, a certain compound, namely crystalline tigecycline, was claimed. The effect relied upon was based on an improved stability with respect to epimerisation. This effect was not even mentioned in the application as filed. The board stated (point 2.3.2 of the Reasons, insertion in squared brackets by the current board) that:

"In this connection [i.e. well-established case law], any effects may be taken into account, so long as they concern the same field of use and do not change the character of the invention."

On this basis, the board took post-published evidence into account, concluded that the effect of improved stability was credibly shown and acknowledged inventive step.

13.7.3 An additional tension exists between the ab initio plausibility and ab initio implausibility standards on the one hand and the principle of free evaluation of evidence on the other hand (see G 3/97 (OJ EPO 1999, 245), point 5 of the Reasons and G 1/12 (OJ EPO 2014, A114), point 31 of the Reasons). It is not immediately clear what could be the legal basis for preventing the patent proprietor from relying on a particular type of evidence of a fact relevant to the outcome of the proceedings. Likewise, it is not clear on what basis a board would be prohibited from taking into account evidence it finds convincing and decisive.

13.7.4 In this respect, it should be stressed that, in accordance with Article 56 EPC, an invention must be considered as involving an inventive step if, having regard to the state of the art, it is not obvious to a person skilled in the art. There can thus be no doubt that inventive step can only be judged in relation to the prior art. The rationale developed in the ab initio plausibility line of case law is, however, that the invention had not been made on the filing date. This finding has been, and can only be, arrived at without considering any prior art. So it may be questionable whether Article 56 EPC is a proper legal basis for plausibility. Indeed, the legal basis for the requirement of plausibility has also been questioned elsewhere. In this respect, the current board would like to refer to the opinion expressed in the UK Supreme Court decision that plausibility "is a court-invented pre-condition to validity" (point 192 of the decision). In R. Jacob, "Plausibility and Policy", Bio-Science Law Review 17(6), 223, the author goes even a step further and states (page 223, first paragraph under "The Statutory Language") that:

"If one actually looks at the words of the EPC a purist would say it is straining the meaning of words beyond breaking point to get plausibility out of them - positively Humpty Dumpty-ish. I suppose it is for that reason that none of the judicial reasoning for getting the notion of plausibility out of either the definition of inventive step (obviousness) or sufficiency has much, or indeed anything, to do with the actual words in the statute. And the word plausibility itself is not in the statute - indeed is not, and never has been, in any patent statute anywhere."

Also in A. Slade, "Plausibility: a conditio sine qua non of patent law?", I.P.Q. 2020, 3, 180-203, the author considers Articles 56 and 83 EPC not to be a proper legal basis for the application of any plausibility standard. She advocates for Article 52(1) EPC as a legal basis since a speculative use of a known compound must fail the initial requirement of this article of being an invention. In this author's view, only if the requirement of Article 52(1) EPC is met can secondary requirements such as lack of inventive step be examined.

14. Conclusion

From the above, it is evident that a referral of questions to the Enlarged Board of Appeal is needed, both to ensure uniform application of the law and because points of law of fundamental importance have arisen. The three referral questions made in the order of the present decision relate to the three lines of case law discussed above, namely whether any plausibility standard can be applied at all (first referral question) and, if so, whether an ab initio plausibility standard (second referral question) or an ab initio implausibility standard (third referral question) is to be applied. The outcome of the referral is decisive for the case at issue since whether post-published evidence D21 can be taken into account depends on this outcome, and since, furthermore, as has been set out above, if taken into account, D21 is relevant to a final decision on inventive step.

15. During the oral proceedings, the board put on screen three preliminary referral questions (for details, see the minutes of the oral proceedings), to which the parties raised the following comments.

The appellant suggested that the questions should define the effective date more clearly. For example, in case of a patent claiming priority, it should be indicated whether the relevant date was the priority or the filing date.

The appellant also argued that it had to be made clear that the effect on which the respondent relied concerned the full ambit of the claim.

The respondent suggested that an additional question should address the burden of proof for (not) achieving the technical effect.

To address the appellant's first comment, the board has replaced "effective date" (which covers priority and filing dates) in the referral questions with "filing date". In the case at hand, evidence D21 was filed after the filing date of the patent in suit. Hence, the question whether evidence can be taken into account that the patent proprietor files after the priority date and before the filing date of the patent in suit does not arise in this case.

As regards the appellant's second comment, the board notes that a clarification that the effect concerns the full ambit of the claim is not deemed necessary. It is clear to the board that the respondent cannot successfully rely on an effect that only relates to a part of the claimed subject-matter (see e.g. T 939/92, points 2.4 to 2.6 of the Reasons).

The issue of the burden of proof for (not) achieving the technical effect raised by the respondent is important but is already encompassed by the current questions. Under the ab initio plausibility line of case law to which the second referral question refers, it is the patent proprietor that has to prove plausibility while in the ab initio implausibility line of case law, to which the third referral question refers, it is the opponent that has to show implausibility.

Order

For these reasons it is decided that:

The following questions are referred to the Enlarged Board of

Appeal for decision.

If for acknowledgement of inventive step the patent proprietor relies on a technical effect and has submitted evidence, such as experimental data, to prove such an effect, this evidence not having been public before the filing date of the patent in suit and having been filed after that date (post-published evidence):

1. Should an exception to the principle of free evaluation of evidence (see e.g. G 3/97, Reasons 5, and G 1/12, Reasons 31) be accepted in that post-published evidence must be disregarded on the ground that the proof of the effect rests exclusively on the post-published evidence?

2. If the answer is yes (the post-published evidence must be disregarded if the proof of the effect rests exclusively on this evidence), can the post-published evidence be taken into consideration if, based on the information in the patent application in suit or the common general knowledge, the skilled person at the filing date of the patent application in suit would have considered the effect plausible (ab initio plausibility)?

3. If the answer to the first question is yes (the post-published evidence must be disregarded if the proof of the effect rests exclusively on this evidence), can the post-published evidence be taken into consideration if, based on the information in the patent application in suit or the common general knowledge, the skilled person at the filing date of the patent application in suit would have seen no reason to consider the effect implausible (ab initio implausibility)?

Today, a Press Communiqué was issued by Spokespersons of the Boards of Appeal of the European Patent Office on the decision of the Enlarged Board in G 1/21. The press release is cited below in full (emphasis added). The Enlarged Board of Appeal "limited the scope of its answer  by confining its order to oral proceedings that are held during a period of general emergency impairing the parties' possibilities to attend in-person oral proceedings at the EPO premises and moreover are conducted specifically before the Boards of Appeal. Accordingly, in its order the Enlarged Board did not address the question whether oral proceedings by videoconference may be held without the consent of the parties in the absence of a period of general emergency. Nor did the order address the question whether oral proceedings by videoconference may be held without the consent of the parties in examination or opposition proceedings before the EPO's departments of first instance." Many interested persons will feel disappointed by the limitation of the scope, as the question remains undecided for oral proceedings in first instance proceedings.

Press Communiqué of 16 July 2021 on referral G 1/21 to the Enlarged Board of Appeal

The original BOA press communique can be found here.

Another press release from the EPO can be found here, and is cited integrally below (emphasis added):

EBoA endorses conduct of oral proceedings by videoconference during pandemic

Also refer to our other blog posts:

• T 1807/15 - Referral G 1/21: OP by ViCo compatible with right to OP acc.Art.116(1) EPC if not all parties agree? (WEDNESDAY, 17 MARCH 2021)
• BREAKING NEWS: G 1/21 - Exclusion and objection of the chairman of the Enlarged Board, but not of other members (THURSDAY, 20 MAY 2021)