T 2156/21 (Antiviral therapy/VIIV) 18-12-2023

1. Admission of D34 and D35 into the appeal proceedings

1.1 These documents were filed by the respondent in its response to the statements of grounds of appeal of appellants 01 and 02. Their admission into the appeal proceedings is objected to by appellant 02.

1.2 D34 and D35 are documents on file on the related opposition to EP 3 127 542, relating to the combination of the same compound of Formula (I) with abacavir. According to the respondent, D34 and D35 are cited to explain the context in which the application as filed would have been read at the filing date by a skilled person, and are provided in response to the opponent's grounds of appeal regarding the content of the application as filed.

1.3 D34 and D35 do not appear to be relevant to the case. The Board did not identify the appellant's arguments that could justify the filing of these documents. The appellants' arguments regarding the addition of subject-matter have been on file since the beginning of the opposition proceedings. The assessment of Articles 123(2) EPC and 76(1) EPC is furthermore only performed in view of the patent or parent application, and not in view of parallel cases. Whether or not a claim has direct and unambiguous basis in the application as filed cannot indeed be decided on the basis of the disclosure of any other document.

Thus, D34 and D35 documents do not address the objection under Article 76(1) EPC put forward by the opponents and their admission would be harmful to procedural economy and for this reason cannot be admitted into the appeal proceedings (Article 12(4) RPBA 2020). Accordingly, the Board decides not to admit D34 and D35 into the appeal proceedings.

2. Main request - Article 76(1) EPC

2.1 The subject-matter of claim 1 of the main request is the combination of the compound of formula (I) with rilpivirine.

2.2 The parent application WO 2011/094150 (D10) relates to combinations of HIV integrase inhibitors and other therapeutic agents.

It discloses more particularly general combinations of either a compound of formula (I), i.e. GSK1349572 or dolutegravir, or a compound of formula (II) or a compound of formula (III) with one or more therapeutic agents selected from nucleotide reverse transcriptase inhibitors, nucleoside reverse transcriptase inhibitors (NRTIs), non-nucleoside reverse transcriptase inhibitors (NNRTIs), protease inhibitors, CCR5 antagonists, CXCR4 antagonists, fusion inhibitors, maturation inhibitors and integrase inhibitors (see D10, page 2, line 30 to page 3, line 19, page 4, line 34 to page 5, line 6). The parent application gives a long list of examples of such therapeutic agents to be combined with compounds of formula (I), (II) or (III) in the paragraph bridging pages 5 and 6. Rilpivirine is one of the compound mentioned in this list. This is the only disclosure of rilpivirine in the parent application as filed.

Thus, the parent application comprises several possible combinations of active ingredients, said combinations being the result of the selection of compounds disclosed in two lists of equal alternatives. The compound of formula (I) and rilpivirine have been singled out from their list among other equal alternatives. The combination of the compound of formula (I) and rilpivirine results therefore from a double selection among two lists of alternative compounds.

Consequently, the claimed subject-matter is not derivable directly and unambiguously from the parent application and the main request does not meet the requirements of Article 76(1) EPC.

2.3 The respondent argued that, when a feature is identified as preferred in an application, its incorporation into the claims cannot constitute a selection, since the claims did not present any new information. In the present case, it was clear that one feature was the core feature of the parent application and that this feature could not constitute an option. This feature was the compound of formula (I), which was disclosed as the preferred compound in the parent application. The respondent cited decisions T 197/08, T 45/12, T 264/16 and T 207/17 in support of its line of argumentation.

2.4 The Board considers this argument not convincing in the present case.

2.4.1 First, it is not at all apparent from the description of the parent application that the compound of formula (I) is the preferred compound. There is in particular no explicit statement in the description of the parent application that the compound of formula (I) has a general preference.

As discussed above under point 2.2, the general disclosure of the parent application on pages 2-6 relates to combinations useful in the inhibition of HIV replication and generally to a combination between either compound of formula (I), or compound of formula (II) or compound of formula (III) with another therapeutic agent disclosed in a long list (see D10, pages 2-6).

The following pages of the parent application disclose the more specific combinations with again either the compound of either formula (I), (II) or (III) with specifically lamivudine, abacavir, tenofovir, efavirenz, GSK2248761, lersivirine, lopinavir, fosamprenavir and atazanavir, and more particularly with abacavir, efavirenz or lopinavir (see page 6, lines 8-27; page 7, lines 10-29; page 8, lines 15-30).

Hence, there is no passage in the description of the parent application which indicates that the compound of formula (I) is the preferred compound.

2.4.2 The Board acknowledges that the claims and the sole example of the parent application relate to combinations comprising systematically the compound of formula (I) with another anti-HIV compound, but considers that said example and claims cannot serve as pointer for a general preference to the compound of formula (I).

The example of the parent application studies indeed the biological activity of the compound (I) with several combined therapeutic agents; the compound of formula (I) was found to be additive with raltegravir, adefovir, and maraviroc and was not affected by the presence of ribavirin, while it was found to be synergistic with stavudine, abacavir, efavirenz, nevirapine, lopinavir, amprenavir, enfuvirtide. Figures 1-3 show the experimental results of HIV inhibition by the combinations of abacavir, efavirenz and lopinavir with the compound of formula (I). These specific and limited preferences demonstrated by the example is reflected by the claims of the parent application, which are directed to a combination of the compound (I) with specifically and exclusively abacavir, efavirenz or lopinavir, namely three active ingredients for which a synergistic effect has been shown (see claims 1 or 5 of D10).

The Board considers however that the disclosure of the original application does not allow to isolate the compound of formula (I) from the context of the example or the claims and then to combine it with a feature disclosed in a distinct part of the description of the parent application, namely the compound riplipvirine. In the Board's view, the disclosure of the claims and the example highlights that the compound of formula (I) is preferred only in combination with specific additional active ingredients and provides therefore a direct basis for these specific combinations, but cannot serve as a basis for a combination with rilpivirine.

2.4.3 The respondent cited several decisions from the EPO jurisprudence in support of its arguments, namely T 197/08, T 45/12, T 264/16 and T 207/17. The Board considers that none of said decisions can apply to the present case.

In all these decisions, it was considered either that a specific feature constituted de facto the only possibility envisaged by the application (see T 197/08 point 3.3), or that an one-dimensional selection did not introduce added subject-matter (see T 45/12 point 3.2.2), and/or that the restriction to a preferred compound was not to be considered as a selection (see T45/12 point 3.2.2, T264/16 point 2.1.1 and T207/17 point 3.2).

In the present case the compound of formula (I) is not the only compound envisaged in the original application for forming a combination with a further anti-HIV (cf. point 2.4.1 above). Moreover, as argued above, the sole example and the claims of the parent application can only be seen as pointers for specific combinations of the compound of formula (I) with the other specific anti-HIV agents disclosed in the example or in the claims, but not for the singling out of the compound (I) and combining it with any other therapeutic agent disclosed in the remaining part of the parent application.

According to the "gold standard", any amendment can only be made within the limits of what a skilled person would derive directly and unambiguously, using common general knowledge, and seen objectively and relative to the date of filing, from the whole of the documents as filed, here the parent application (G 2/10, OJ 2012, 376). In the present case, the compound rilpivirine is disclosed in the parent application only in the context of a long list of anti-HIV products which may be associated with any equal alternative compound of formula (I), (II) or (III). As discussed above, this represents a multiple selection from different lists which is not derivable directly and unambiguously from the parent application.

3. Auxiliary request 1 - Article 76(1) EPC

Claim 1 of auxiliary request is identical to claim 1 of the main request, this request differing from the main request in the suppression of claims 2-9. The conclusions reached for the main request apply therefore mutatis mutandis to auxiliary request 1 which does not meet the requirements of Article 76(1) EPC.