EPO Decision G 1/15 on Partial Priorities and Toxic Divisionals: Relief and Risks In Europe, the claiming of multiple priorities and the concept of partial priority in the context of a single patent claim are provided for by Art. 88(2) EPC, second sentence, which reads: Where appropriate, multiple priorities may be claimed for any one claim. Although this provision only refers to multiple priorities, it has long been well recognized that it also applies to partial priority in a narrow meaning, i.e., also if only a single priority is claimed (this terminology is discussed, e.g., in Schricker GRUR Int 1967, 3). The priority date may then apply to one part of the subject matter of a claim, and the filing date to the remainder of the claim. Regarding European patent applications claiming subject matter that was added after the date of at least one priority application, Art. 88(3) EPC also provides: If one or more priorities are claimed in respect of a European patent application, the right of priority shall cover only those elements of the European patent application which are included in the application or applications whose priority is claimed. This further confirms that a claim of a European patent application may cover subject matter going beyond what was disclosed in a priority application, and may then only be partially entitled to priority, namely only for subject matter which was disclosed in the priority application. A claim may thus in principle be split into partial priority domains of subject matter having different effective dates, depending on whether the subject matter in question is entitled to a particular priority claim. Under EPO practice such splitting of the claim scope has not generally posed particular problems when the different domains have been expressly individualized as alternatives by the wording of the claim and these alternatives also correspond exactly to elements that either
2 are or are not disclosed in a priority application. However, until the recent decision G 1/15 of the EPO Enlarged Board of Appeal (dated November 29, 2016 but published in full only on February 1, 2017) it was not clear under EPO practice whether such subject matter splitting was allowable when the possible alternative subject matters forming partial priority domains were not made explicit in the claim, but were identifiable within the scope of a generic claim term only conceptually, by reference to a narrower disclosure found in the priority application and merely encompassed within the scope of a broader generic claim term employed in the later filing that claims priority. Typical examples are the broadening of a chemical formula or of a numerical range, but the issue applies to any generic broadening of claim terms relative to the terminology of the priority application. In G 1/15 of the EPO Enlarged Board of Appeal has now clarified that the concept of partial priority applies in a straightforward and usually applicant/patentee-friendly manner to any claim term which has been broadened in a generic manner in comparison to the priority document. This decision also effectively renders obsolete the topic of toxic divisionals and similar cases of self-collision arising from poisonous priority, which has troubled applicants and patentees in Europe for the larger part of the last decade. The approach to partial priority that has been confirmed in G 1/15 provides an antidote to such self-collision within the same patent family, at least in all usual and generally foreseeable circumstances. Enlarged Board decision G 1/15 became necessary because after Enlarged Board decision G 2/98 the case law of the EPO Boards of Appeal on partial priority diverged into two irreconcilable approaches. According to one line of case law, which until G 1/15 also became the approach generally applied by first-instance examining and opposition divisions, partial priority was not acknowledged for subject matter that had basis in the priority application but was not individualised as such in a generically broadened claim (e.g., T 1127/00, T 184/06, T 1443/05, T 1877/08 and T 476/09). This restrictive approach required different subject matter domains corresponding to different effective dates to be expressly identified as distinct alternatives by the wording of the claim, using the word or. This approach was based on a restrictive interpretation of a statement found in previous decision G 2/98 of the Enlarged Board of Appeal, namely: The use of a generic term or formula in a claim for which multiple priorities are claimed in accordance with Article 88(2) EPC, second sentence, is perfectly acceptable under Articles 87(1) and 88(3) EPC, provided 2
3 that it gives rise to the claiming of a limited number of clearly defined alternative subjectmatters (point 6.7 of the reasons). However, a different line of case law, represented by cases T 1222/11 and T 571/10, argued that the above restrictive approach failed to recognize that the Enlarged Board in G 2/98 took a teleological and historical approach to the interpretation of Art. 88(2) EPC, second sentence, and held that the legislative intent underlying this provision was expressed by a particular Memorandum drawn up by FICPI for the Munich Diplomatic Conference prior to the adoption of the EPC, on the issue of multiple and partial priorities in the case of a single claim. T 1222/11 and T 571/10 therefore followed the approach to this issue that is explained in the Memorandum, and interpreted the proviso of G 2/98, point 6.7 of the reasons (underlined above) entirely differently. In G 1/15 the Enlarged Board of Appeal has now confirmed that this more lenient case law is correct, essentially adopting the reasoning of T 1222/11 and T 571/10. According to this Memorandum approach, when the terms in a claim have been broadened compared to the corresponding disclosure in the priority document, a partial priority entitlement simply applies to the extent that the claim scope corresponds to the disclosure of the priority document. The broadened, generic claim scope in question is thus conceptually divided into subject matter domains having different effective dates purely on the basis of the narrower disclosure in the priority document(s). This purely conceptual subdivision of a generic claim term into partial priority domains is independent not only of the wording of the claim as such but also of the content of the later application as a whole. Within generic claim terms that are not as such entitled to priority across their entire scope, the basis for any narrower subject matter that is entitled to priority is found in the priority document. Under the former, restrictive approach which G 1/15 has rejected, when a generic term such as a chemical formula or numerical range was broadened with respect to the priority application, priority was lost entirely. Any intervening disclosure corresponding to the content of the priority application during the priority interval thus destroyed the novelty of the claim. In contrast, under the lenient Memorandum approach now confirmed in G 1/15, the priority entitlement is automatically maintained to the extent that subject matter is disclosed for the first time in the priority application, which will generally protect the claim from any 3
4 intervening disclosure corresponding to or falling within the scope of the content of the priority application. Therefore, Enlarged Board decision G 1/15 effectively removes the risks that have in recent years been posed to patent applicants and patentees in Europe by the concept of toxic divisional applications, toxic published EP priority applications and the like. In principle under the EPC, and particularly under the restrictive, now-obsolete case law discussed above, the above-mentioned intervening disclosure could be, e.g., content of a divisional, codivisional or a parent application, to the extent that such an application from the same family was entitled to priority. It could also be a priority application itself, if that was a European application and allowed to be published. Any such related application could, in principle, be considered to be an entirely independent European patent application, such that any of its content that is entitled to the priority date may, once published, be considered to be earlierfiled/later-published prior art under Art. 54(3) EPC and thus relevant for novelty, if the later claim in question is for some reason not entitled to priority. Under the restrictive approach that existed prior to G 1/15, priority applications (if European and published), and in any case any priority-entitled content of published divisional, codivisional and parent applications could become toxic and destroy the novelty of claims which have been generically broadened beyond the priority application (cf., e.g., EPO Board of Appeal decisions T 1443/05, T 1496/11 and the discussion in T 557/13, the referring decision in G 1/15). However, following G 1/15, if a claim is generically broadened beyond the priority application, the priority-entitled disclosure of such related applications is not generally expected to become prior art at all, due to the automatic protection that is afforded by the lenient Memorandum approach to partial priority. The referral to the Enlarged Board in G 1/15 also included the question, essentially, of whether, if not the concept of partial priority, any other aspect of the EPC prevented the citation of a parent or divisional application of a European patent application as prior art relevant for novelty under Art. 54(3) EPC. The Enlarged Board held that, in light of its ruling on how partial priority was to be applied in practice so as to prevent such self-collision, it was not necessary to decide or comment on this question separately. 4
5 While the confirmation of the Memorandum approach is generally a welcome development for applicants, it may also involve a flip-side. This was made evident in T 1222/11, a decision which has been expressly confirmed as correct by the Enlarged Board in G 1/15. This flipside of the Memorandum approach means that it is now it more important to plan patent portfolios such that the definitive European or international application for a given invention is filed within the twelve-month period after the earliest patent filing of the narrowest embodiment of the invention. This is a consequence of the principle that partial priority / subject-matter domains may be identified conceptually within a generic claim scope by comparison with narrower disclosures in the priority application, in conjunction with the further basic principle that priority under the EPC can only be claimed from the first application by the applicant (or by his predecessor in title) for the subject matter in question. The case underlying decision T 1222/11 revealed in practice how these two principles can work in conjunction to the detriment of patent applicants. To be consistent on all aspects of priority, the Board in that case applied the same approach of conceptually identifying subject matter domains within the scope of a generic claim or disclosure when assessing, by comparison with yet earlier applications, whether the priority application was in fact the first application for all conceptually identifiable priority domains its disclosure encompassed. A yet earlier-filed application by the same applicant that was published in the priority interval and disclosed a narrow embodiment encompassed by the definition used in both the priority application and the claim in question therefore ultimately destroyed the novelty of the claim. Priority could not be claimed in respect of the narrow embodiment because at least in the partial subject matter domain of that narrow embodiment, the priority application was not the first application. In summary, considering at least that it is common practice (1) to improve inventions in the course of the priority interval and broaden the scope of the protection that is sought in a later application claiming priority and (2) to file divisional applications, the conformation of the Memorandum approach by the EPO Enlarged Board of Appeal in G 1/15 comes as a relief to patent applicants and patentees in Europe. It now once again appears generally safe to file divisional applications in Europe, at least in all usual and foreseeable circumstances. However, it is now more important to plan patent portfolios such that the definitive European or 5
6 international application for a given invention is filed within the twelve-month period after the earliest patent filing of the narrowest embodiment of the invention. These conclusions are expected to apply not only at the EPO but in principle also to national practices in EPC contracting states such as Germany and the UK, which do take into account the practice of the EPO in such matters, particularly if case law of the Enlarged Board of Appeal exists. 6