T 1089/11 (Serum-free medium/BAVARIAN NORDIC) 12-12-2017

Admission of the new evidence into the proceedings

1. Pursuant to Article 12(4) of the Rules of Procedure of the Boards of Appeal (RPBA), it is a matter of discretion of the board whether or not evidence filed for the first time in appeal proceedings, but which could have been presented in the previous proceedings, is admitted and considered.

2. Both the appellants and the respondent filed additional evidence in appeal proceedings. Appellant II submitted documents (62) to (67) as support for its line of argument concerning the interpretation of the term "serum-free medium" used in claim 1. The construction of this term is relevant to the question whether or not a medium containing BMS as described in document (15) is to be considered a "serum-free medium". These pieces of evidence have been filed as an attempt to refute the adverse findings in this respect in the decision under appeal (see page 14, lines 24 and 25 of the decision "...BMS does not fall into the scope of a "serum-free medium""). Hence, documents (62) to (67) have been filed at the earliest possible point of time and are to be admitted into the proceedings.

3. Document (68) was submitted by appellant II to support an objection of lack of inventive step, in particular as evidence that the use of the growth factor EGF in serum-free medium for the cultivation of primary avian cells was known in the art at the relevant date. Since claim 3 of the patent as granted was directed to a method using serum-free medium comprising EGF, document (68), if considered to be relevant evidence for the use of such a medium, should have been submitted either together with the notice of opposition or, at the latest, during the opposition proceedings. Despite the board indicating in its communication in preparation of the oral proceedings that it might become necessary to discuss the admission of document (68), any circumstances that may eventually have prevented appellant II from filing this document in opposition proceedings were not put forward. Nor are any apparent from the file.

4. Document (69) was submitted by appellant I as evidence that growth factors like EGF are normal components of serum. In its communication in preparation of the oral proceedings, the board observed that the same evidence had already been provided by document (48) filed in opposition proceedings. If appellant I considered that the probative value of document (48) differed from that of document (69), the question arose why the latter could not have been filed during opposition proceedings. Appellant I did not reply to the board's communication. Hence, the board sees no reason why document (69) should be admitted and considered in appeal proceedings.

5. Consequently, exercising its discretion under Article 12(4) RPBA, the board decides not to admit documents (68) and (69) into the proceedings.

6. The appellants did not oppose the admission into the proceedings of documents (70) to (73) submitted by the respondent to address issues raised in the statements of grounds of appeal. Thus, these documents are admitted into the proceedings.

Article 123(2)(3) EPC

Claim 1

7. Appellant I's argument that there is no basis in the application as filed for the subject-matter of amended claim 1, in particular as regards the feature "... wherein the serum free medium of steps (a) to (c) comprises epidermal growth factor (EGF)", cannot be accepted. The subject-matter of claim 1 according to the main request (see section V above) can be derived, directly and unambiguously, from claim 13 and the passage of the description starting on page 11, line 8, in particular page 12, lines 18 to 22 of the application as filed. Claim 13 of the application as filed is directed to a method for the amplification of a virus comprising three steps: (i) cultivation of primary avian cells, (ii) infection of the cells with a virus, and (iii) cultivation of the infected cells to produce the virus. Step (i) of the method is defined by reference to, inter alia, the method for the cultivation of primary avian cells of claim 3, according to which the growth factor comprised in the serum free medium is an epidermal growth factor (EGF). See also the passage on page 11, lines 13 to 17 of the application as filed in which it is stated that the conditions, definitions and preferred embodiments disclosed for the method of cultivation of primary cells apply equally for the definition of the first step of the method for the amplification of a virus.

8. The passage on page 12, lines 18 to 22 of the application as filed reads:

"The serum free medium that is used in the second and third step of the method for the amplification of a virus may be the same medium that has already been used before, i.e. a serum free medium comprising a factor selected from growth factors and attachment factors, depending on the cell type."

The wording "the same medium that has already been used before" in this passage can only be interpreted to refer to a medium as used for cultivating the primary cells in the first step of the method, i.e. "... a serum free medium comprising a factor selected from the group consisting of growth factors and attachment factors, depending on cell type" (see the identical wording used on page 11, lines 11 to 13 of the application as filed to describe the medium used in step (i)). Since according to the application as filed the medium used for cultivating the primary avian cells in step (i) may comprise epidermal growth factor (EGF), so does the medium used in steps (ii) and (iii) (steps (a) to (c) in claim 1 as presently on file). Hence, the subject-matter of amended claim 1 does not extend beyond the content of the application as filed.

Claim 5

9. The board does not share appellant II's view that the passage on page 10, lines 8 to 10 of the application as filed does not disclose directly and unambiguously the subject-matter of present claim 5. A person skilled in the art reading the passage in question ("..., it is also possible to add two or more factors selected from growth factors and attachment factors to the medium.") in connection with the next sentence disclosing a specific embodiment (page 10, lines 10 to 12; "The medium may preferably comprise EGF and fibronectin, ..."), understands that the passage on lines 8 to 10 discloses the addition of (at least) one growth factor (e.g. EGF) and (at least) one attachment factor (e.g. fibronectin). Hence, contrary to appellant II's contention the subject-matter of amended claim 5 does not extend beyond the content of the application as filed.

10. In view of the above, the board concludes that Article 123(2) EPC is not contravened. No objections under Article 123(3) EPC were raised by the appellants in appeal proceedings.

Article 84 EPC

Claim 1

11. The findings in the decision under appeal concerning claim 1 were contested by appellant I arguing that the feature "... wherein the serum free medium of steps (a) to (c) comprises epidermal growth factor (EGF)" introduced into claim 1 is ambiguous because it can be construed as meaning that the same serum free medium is used in steps (a) to (c), or that different serum free media are used in the different steps, each medium comprising EGF.

12. The board cannot accept this argument. If, as in the present case, a feature can be read to cover two different embodiments of the claimed subject-matter, this does not necessarily mean that the feature is ambiguous, and that a claim including it lacks clarity within the meaning of Article 84 EPC. As a rule, a claim is considered to lack clarity if the exact distinctions which delimit the scope of protection conferred by the claim cannot be learnt from it (see decision T 6/01 of 2 December 2003, paragraph 14). In the board's view, the scope of protection of claim 1 is clearly delimited: the claim encompasses two alternative embodiments of the method of the invention, an embodiment in which the same serum free medium comprising EGF is used in all three steps of the method, and a different embodiment in which, as illustrated by Example 7 of the application as filed, the composition of the serum free medium used in the different steps varies, but each medium comprises EGF.

13. Appellant II's argument that claim 1 lacks clarity because there is no reference in step (b) to a serum free medium, cannot be accepted either. It is undisputed that, although not expressly specified in step (b), the infection of the primary avian cells with a poxvirus (step (b) of the claimed method) takes place in a medium. This medium can be either the serum free medium used for the cultivation of the cells, as specified in step (a), or a fresh medium which, as required by the feature introduced into claim 1 ("... wherein the serum free medium of steps (a) to (c) comprises epidermal growth factor (EGF) ..."), must also be a serum free medium comprising EGF.

14. In connection with its objection that the amended claims lack support in the description, appellant I pointed to paragraphs [0042] and [0068] of the patent as granted. However, the board observes that, for the assessment whether or not the amended claims fulfil the requirements of Article 84 EPC, what has to be considered is the amended specification adapted to the claims as filed by the respondent during the oral proceedings before the opposition division, rather than the patent as granted.

15. It is stated in paragraph [0042] of the amended specification that the serum free medium used in the second and third step of the method "... is the same medium that has already been used before, i.e. a serum free medium comprising EGF and optionally attachment factors, depending on the cell type". It is clear from this passage that the serum free medium used in the three steps of the method according to the invention comprises EGF and, optionally, also attachment factors, in particular when the primary cells are adherent cells (see [0033] of the amended specification). The board is convinced that this passage of the amended description provides support, within the meaning of Article 84 EPC, for the amended claims 1 and 5, and that there is no need for either claim 1 or claim 5 to specify any particular "cell type". As regards paragraph [0068], which is part of Example 4, it should be noted that in the amended specification this example is marked as a reference example and that, therefore, it does not serve the purpose of supporting the amended claims.

Claim 5

16. Appellant I's further objection of lack of clarity concerning the term "attachment factor" in amended claim 5 is not justified. The term "attachment factor" has a clear meaning in the relevant art: it designates a compound that promotes adhesion of cells to a solid support. Neither the fact that the term in question is not defined in the patent, nor the fact that different structurally unrelated compounds - as listed in document (58) - can function as attachment factors may be regarded as prejudicial to the clarity of claim 5.

17. In sum, having considered the arguments put forward by the parties in appeal proceedings, the board concludes that the claims of the main request meet the requirements of Article 84 EPC.

Article 83 EPC

18. The findings on Article 83 EPC in section 20.2 of the decision under appeal were contested by appellant I arguing that the invention as claimed in claim 1 cannot be carried out over the whole scope of the claim because certain poxviruses cannot grow in any primary avian cell, but only in particular cells.

19. It is specified in claim 1 that the primary avian cells used in the method are cells that allow the productive replication of the poxvirus to be amplified. In its communication in preparation of the oral proceedings, the board stated that the notional person skilled in the art in the technical field of the invention could be considered to be an experienced practitioner who is aware of which particular cells under specific conditions allow the productive replication of particular poxviruses. This has not been contested by the appellants. Nor have they disputed that the application as filed clearly discloses the replication of MVA in CEF cells. Neither the passage of the application as filed to which appellant I referred (see page 7, lines 13 to 23, which corresponds to paragraph [0024] of the patent in suit) nor any of the documents on file cast doubts that the method of claim 1 can be applied to amplify MVA in CEF cells.

20. Appellant I argued further that the disclosure in the application as filed was insufficient as regards the attachment factor, the EGF and/or the fibronectin concentration in the medium, and further components of the serum-free medium required for a particular cell type. This objection cannot be accepted either. As stated in the board's communication, at the relevant date various attachment factors were known in the art (see document (58)), and the knowledge of particular medium components required by specific cells belonged to the common general knowledge of the skilled person at that time. This was not disputed by appellant I. As regards EGF and fibronectin, concentrations suitable for carrying out the invention are disclosed in the application as filed (see passage from page 9, line 24 to page 10, line 4), and there is no evidence on file supporting appellant I's contention that finding out the optimal EGF and fibronectin concentration in a medium used for a specific combination of poxvirus and primary avian cell would require inventive skills or more than routine experiments.

21. Finally, appellant I asserted that a skilled person could not put into practice a method according to claims 9 to 12 because the patent did not teach precisely how the "extracts" specified in these claims contribute to the solution of the technical problem. Even if this objection were to be considered as relating to Article 83 EPC - rather than, possibly, to Article 56 EPC, there is no evidence on file which may raise doubts on the feasibility of amplifying a poxvirus in an avian primary cell using a serum-free medium comprising EGF and a microbial or plant extract or an extract from a non-mammalian animal. Hence, appellant I's argument cannot be accepted.

22. Summarising the above, the arguments put forward by appellant I to support its objection of lack of sufficient disclosure fail to convince the board.

Article 87 EPC

23. While the findings concerning the correction of the priority declaration (see section 18.1.1 of the decision under appeal) were not contested in appeal proceedings, appellant I maintained its objection that the priority rights could not be validly claimed. In its view, the Danish application filed on 5 September 2002 was not the first application within the meaning of Article 87(1) and (4) EPC, because the earlier application PCT/EP02/07280 (document (1) in these proceedings) already disclosed the claimed invention.

24. Appellant I's view is not shared by the board. Document (1) discloses a process for improving the propagation of a poxvirus in a cell culture by reducing the temperature of the culture after infection below 37°C. In Example 1, the effect of the temperature on the multiplication of MVA in primary CEF cells is described. Primary CEF cells are cultivated in VP-SFM medium (a serum-free medium comprising EGF), and then infected with MVA using serum-free RPMI medium. It is undisputed that the RPMI medium does not comprise EGF.

25. The board cannot acknowledge in the passage on page 17, lines 9 to 25 of document (1) a clear and unambiguous disclosure of the use of a serum-free medium containing EGF in either the infection or the propagation step (steps (b) and (c) of the method of amended claim 1 of the patent in suit). The fact that neither the removal of the VP-SFM medium comprising EGF, nor a washing step between the cultivation step and the subsequent steps of infection with the virus and cultivation of the infected cells, are mentioned in this passage cannot be regarded as a clear teaching that EGF is to be added to the medium used during the viral infection and replication, as required by amended claim 1. Contrary to appellant I's view, the passage on page 10, lines 9 to 14 of document (1) gives no indication whatsoever that the medium used for the cultivation of the cells before infection and for the production of the virus may be a serum-free medium comprising EGF.

26. In view of the above, the Danish priority application is considered to be the first application disclosing the method according to the present invention. Hence, the priority right is validly claimed, and the priority date is the relevant date for the assessment of novelty and inventive step. Consequently, document (1), a European application filed under the Patent Cooperation Treaty on 2 July 2002 and published on 30 January 2003 is to be regarded as comprised in the state of the art only for the assessment of novelty (Article 54(3)(4) EPC 1973).

Article 54(3)(4) EPC 1973

27. As stated in paragraphs 24 and 25 above, document (1) does not disclose, clearly and unambiguously, a method for the amplification of a poxvirus which comprises the step of infecting primary avian cells with poxvirus, and cultivating the infected cells in a serum-free medium containing EGF. Hence, document (1) does not prejudice the novelty of the subject-matter of claim 1.

Article 56 EPC

28. The findings on Article 56 EPC in the decision under appeal were contested by both appellants relying on document (15) as the closest state of the art. Alternatively, appellant I relied on document (55). Both lines of argument fail to convince the board.

Document (15) as the closest state of the art

29. Document (15) relates to paramunity, an antigen non-specific mechanism developed by warm-blooded animals, especially mammals and birds, which allows the animal to mount an immediate defence when confronted with foreign substances, infectious pathogens, toxins or transformed cells of the animal itself (see page 1, first and second paragraph). It describes multipotent paramunity inducers based on combinations of poxvirus components, a method for preparing the paramunity inducers, and their use as therapeutics in human and veterinary medicine. The paramunity inducers described in document (15) are based on the observation that the combination of poxvirus components derived from various poxvirus strains brings about not only an additive or supplementary effect, but a potentiation of the respective paramunizing action (see page 4, first paragraph).

30. According to document (15), poxviruses used as components for the multipotent paramunity inducers can be propagated in both primary and secondary cell cultures or in permanent cell lines, using known techniques (see passage from page 12, line 27 to page 14, line 27). Example 1 describes the propagation of the attenuated avipox strain HP1 in chicken embryo fibroblast (CEF) cultures by cultivating the fibroblasts in "... a totally synthetic medium comprising 10% BMS (serum substitute medium), 10% lactalbumin hydrolyzate and MEM (minimal essential medium)" (see page 22, lines 7 to 9). After inoculation with the virus, MEM is used as medium for maintenance until progeny poxvirus is produced (see page 22, lines 11 and 12).

31. It was common ground that the method described in document (15) differs from the method according to claim 1 in that the medium used in steps (a) to (c) of the latter contains EGF. It was however a subject of dispute whether a medium containing BMS as described in document (15) can be regarded as a "serum free medium" as specified in claim 1.

32. In the decision under appeal, the opposition division found that BMS is a complex medium that includes an important protein fraction of the serum, and that, therefore, "... BMS does not fall into the scope of a 'serum-free medium'" (see page 14, sixth paragraph, lines 5 to 7 of the decision). The appellants questioned the opposition division's interpretation of the term "serum free medium" relying on documents (36) and (62) to (68). However, this evidence does not support their view that BMS is to be considered to be a serum free medium as specified in claim 1.

33. According to the established jurisprudence of the Boards of Appeal, the terms used in patent documents should be given their normal meaning in the relevant art. If a term is ambiguous or unclear, the description and the drawings may be used for interpreting the claims (see, e.g., decisions T 23/86, OJ 1987, 316).

34. It is apparent from the documents to which the appellants referred that the term "serum free" may be given different meanings depending on the focus of the particular publication, and that the terms "serum free" and "serum substitute" are sometimes used indiscriminately, even though the meaning of the latter term is more general as it refers to media in which whole serum has been replaced by either a serum fraction or non-serum components. For instance, in documents (65) and (66), which focus on media with a reduced protein content in order to facilitate purification of the monoclonal antibodies produced by hybridomas, no clear distinction is made between media commercialized as "serum free" or as "serum substitute". The same is true for document (37). It should be noted that a clear distinction is, in some cases, not possible because the exact composition of media commercialized as serum free media is not provided by the manufacturers (see document (66), page 136, "Determination of protein content"; and document (36), page 1, first paragraph under the heading "Content of Serum-Free Media").

35. Document (36), to which both appellants referred, is concerned with ethical issues related to animal welfare. In this context, the statement on which the appellants relied ("By definition serum-free medium lacks whole serum as an ingredient, but it may not be entirely free of serum-derived products"; see page 1, second paragraph under the heading "Content of Serum-Free Media") is to be understood, rather than as a definition, as a warning that even culture media labelled as "serum-free" by the manufacturer may still contain residual serum components. This applies also to the identical wording in the passage of document (64) on page 942, left-hand column, second full paragraph from the bottom.

36. In documents (62) and (63), it is stated that serum free media may contain serum constituents (see document (62), page 157, lines 2 and 3 of the second paragraph under the heading "Introduction"; and document (63), page 56, left-hand column, lines 12 to 16). However, it is also stated that "... those constituents are known, and the level of each component is precisely defined" and "... for the most part highly purified" (see document (63), page 57, left-hand column, lines 3 to 9; and sentence bridging centre and right-hand columns).

37. It follows from the above that, as used in the art, the term "serum free medium" refers clearly to a medium which does not contain whole serum, but the term seems to be rather vague as regards the possible content of serum components. In such a situation and according to the jurisprudence of the Boards of Appeal, the meaning of the term "serum free medium" has to be determined from the point of view of a skilled person who reads claim 1 in the context of the application and against the background of his/her common general knowledge (see T 1599/06 of 13 September 2007, point 3.1 of the Reasons).

38. It is clear from the statements in the second and third paragraph on page 3 of the application as filed that the method of the invention addresses the problem of a potential risk of contamination with pathogenic agents, if poxviruses intended for use as vaccines are prepared using a medium containing serum, e.g. bovine or fetal calf serum. In particular, the agent causing bovine spongioforme encephalopathy (BSE) is mentioned as one of the many potential problems associated with the use of bovine serum supplement (see page 3, lines 19 to 23 of the application). Having in mind that the agent causing BSE is suspected to be a protein, a person skilled in the art reading the application understands that the term "serum free medium" as used therein can only mean a medium containing neither whole serum, nor any serum fraction comprising a significant amount of uncharacterized proteins.

39. The medium used in Example 1 of document (15) comprises 10% BMS, which is described as a serum substitute medium (see page 22, lines 7 and 8). BMS, which was commercialized as a "serum alternative", is derived from fetal bovine serum (FBS) ("Using only fractions of FBS, ..."; see product datasheet filed as document (31)). Although its total protein and IgG content is significantly lower than that of FBS (it contains only one third of the proteins associated with serum), BMS still contains a substantial part of (uncharacterized) serum proteins. Hence, a person skilled in the art would not regard a medium containing BMS as a "serum free medium" within the meaning of claim 1.

40. Thus, the method described in document (15) differs from that defined in claim 1 in that the latter uses a serum free medium for growing, infecting and cultivating the primary avian cells after infection, and that the medium used in all three steps contains EGF.

41. The technical effect associated with these features is a substantial reduction of the risk of contamination with pathogenic agents such as viruses, while maintaining poxvirus yields that are at least comparable to those obtained using a medium containing animal sera.

42. Appellant II disputed that the poxvirus yields disclosed in the application could be compared to those described in document (15) arguing that the experimental conditions were not the same. However, it did neither contest the statement in the application as filed that primary avian cells grow poorly in serum free medium without additional growth factors (see page 6, lines 21 to 23), nor argued, let alone filed any evidence that the virus titers disclosed in the application as filed for the method of the invention (see Examples 7 and 8 in the application as filed) are not comparable to those obtained in medium containing serum. Appellant II's further argument that the presence of EGF in steps (b) and (c) of the method according to claim 1 has no technical effect whatsoever is also unconvincing. Claim 1 requires that the medium used in steps (a) to (c) is a serum free medium which comprises EGF. The technical effect achieved by the use in all three steps of a serum free medium comprising EGF is a reduction of the risk of viral contamination, compared to a method using a medium that contains serum fractions as described in document (15).

43. Even though document (15) does not mention a potential contamination of cell cultures used for the production of vaccines with pathogenic agents as a problem, it was not a subject of dispute between the parties that, at the relevant date, this was a matter of general concern. Consequently, starting from the method described in document (15) the objective problem to be solved by the skilled person can be formulated as the provision of an effective and reliably safe method for the amplification of poxviruses in primary avian cells. Neither appellant has convincingly disputed that this problem is solved by the method of claim 1.

44. Having considered the evidence on which the appellants relied, the board is not persuaded that the solution proposed in claim 1 was obvious to a person skilled in the art at the relevant date.

45. Both appellants referred to document (5) which describes animal cell culture media comprising plant-derived nutrients that substitute animal-derived products. As possible components of the medium, document (5) mentions growth factors, interleukins, colony-stimulating factors, interferons and lymphokines. EGF is one of the ten growth factors mentioned in this document. Like the opposition division in the decision under appeal, the board observes that document (5) does not relate to media for the amplification of viruses, but to media for the cultivation of animal cells. It is not apparent to the board why a person skilled in the art seeking to amplify poxviruses would - without the benefit of hindsight - have not only turned to document (5), but also chosen among the numerous cell culture media described therein specifically a medium comprising EGF. Moreover, even if the skilled person might have considered using such a medium, he/she would not have derived from document (5) anything that gave him/her a reasonable expectation to be able to effectively amplify poxviruses in primary avian cells, i.e. to obtain viral titers comparable to those obtained in serum containing media. Hence, the appellants' objection of lack of inventive step based on a combination of document (15) with document (5) must fail.

46. Document (28), to which appellant II referred, describes VP-SFM, a cell culture medium formulated without any human or animal derived components other than human recombinant EGF and human recombinant insulin. Among the advantages of VP-SFM, document (28) mentions a reduced risk of viral contamination and equivalent virus titers compared to serum supplemented media. It is stated in document (28) that VP-SFM is designed specifically for the growth of VERO, COS-7, MDBK, BHK-21, HEp2 and other important cell lines, which require little or no adaptation to the culture medium, whereas for other cell lines sequential adaptation may be necessary. It should be noted that, while immortalized cell lines can be adapted to a medium by subculturing, primary cells cannot be subcultured. Thus, a person skilled in the art reading document (28) would not have reasonably expected to be able to use VP-SFM for cultivating primary avian cells and amplifying poxviruses. Consequently, the claimed invention cannot be regarded as obvious in view of document (15) combined with document (28).

47. Appellant I relied also on documents (22) and (25). Document (22) concerns a serum free or serum depleted medium containing growth factors that stimulate the proliferation of stromal cells and cells from a variety of tissues or organs, inter alia, epidermal growth factor (EGF), and document (25) describes that the addition of EGF and insulin to cultures of normal chicken heart mesenchymal cells causes these cells to proliferate at a rate comparable to that of their Rous sarcoma virus-infected counterparts. However, neither document (22) nor document (25) suggests that the media described therein may be suitable for an effective amplification of poxviruses in primary avian cells. Thus, combining document (15) with either document (22) or document (25) can only be considered obvious with the benefit of hindsight.

Document (55) as the closest state of the art

48. Appellant I relied - for the first time in appeal proceedings - on document (55) as the closest state of the art in combination with document (28). Document (55) is the publication in the Bundesanzeiger of a European Community directive concerning particular requirements for the manufacture and testing of vaccinia virus vaccines used for pre-vaccination. According to section 2.2 of the directive, MVA vaccines are amplified in primary CEF cells using a chemically defined, protein-free culture medium ("... unter einem chemisch weitgehend definierten, eiweißfreien Kulturmedium ..."). Contrary to appellant I's view, the board does not consider that a combination of the teachings of documents (55) and (28) was obvious to a skilled person. Even if - for the sake of argument - the board were to accept that the skilled person had a motivation to combine the two documents, for the reasons given in paragraph 46 above there was no reasonable expectation that VP-SFM could be used for cultivating primary avian cells and amplifying poxviruses.

49. Summarizing the above: the arguments and evidence brought forward by the appellants fail to convince the board that the method of claim 1 lacks an inventive step within the meaning of Article 56 EPC.

Article 113(1) EPC

50. In its communication pursuant to Article 15(1) RPBA, the board expressed a reasoned provisional opinion on the issues to be discussed at the oral proceedings. The reasons given by the board in the present decision were known to the appellants, as they are essentially those given in the decision under appeal and/or in the board's communication. The appellants were given the opportunity to make written and/or oral submissions in respect of the grounds and evidence on which the present decision is based. However, they neither replied in substance to the board's communication nor attended the oral proceedings. Under these circumstances, the board considers that the provisions of Article 113(1) EPC are complied with.