T 1641/21 (Canine vaccine against leptospira bratislava/ZOETIS) of 11.7.2024

Summary of Facts and Submissions

I. European patent No. 1 799 253 ("the patent") was granted on European patent application No. 05 789 769.6 which was filed as international application under the PCT published as WO 2006/038115 (application as filed or application) claiming priority from US application 10/959,757 filed on 6 October 2004. The patent is entitled "Multivalent canine vaccines against Leptospira bratislava and other pathogens".

II. Two oppositions were filed against the patent, which was opposed under Article 100(a) EPC on the grounds of lack of novelty (Article 54 EPC) and lack of inventive step (Article 56 EPC) and under Article 100(b)

and (c) EPC.

III. An appeal was lodged by the patent proprietor against a first decision of the opposition division revoking the patent. The board, in the same composition as the present one, decided in the first appeal proceedings that the set of claims of the main request filed in the oral proceedings before the board on 10 January 2019 complied with the requirements of Articles 123(2)

and (3), 84 and 54 EPC. The case was remitted to the opposition division for further prosecution on the basis of the set of claims of the main request

(T 148/15, Order).

IV. In a second decision revoking the patent, the opposition division held that the subject-matter of claim 3 of the main request filed on 10 January 2019, of claim 1 of auxiliary request 3 filed on 26 March 2021 and of claim 1 of auxiliary requests 8 and 9, both claim requests filed on 27 April 2021, lacked an inventive step and that claim 1 of each of auxiliary requests 1, 2, 4, 5, 6 and 7, all filed on 26 March 2021, did not meet the requirements of Article 123(2) EPC.

V. The present appeal of the patent proprietor (appellant) is against this second decision of the opposition division. Opponents 1 and 2 are respondents I and II (or "respondents") to the appeal.

VI. With its statement setting out the grounds of appeal, the appellant submitted sets of claims of a main request and auxiliary requests 1 to 3. The main request and auxiliary request 2 are identical to auxiliary requests 8 and 9 and auxiliary requests 1 and 3 are identical to auxiliary requests 6 and 7, which were considered in the decision under appeal, respectively.

Claim 1 of the main request reads as follows:

"1. A vaccine composition for use in protecting dogs against infection caused by Leptospira bratislava comprising a Leptospira cell preparation of Leptospira bratislava and a carrier, and further comprising one or more antigens of another canine pathogen, selected from the group consisting of canine distemper (CD) virus, canine adenovirus type 2 (CAV-2), canine parainfluenza (CPI) virus, canine coronavirus (CCV), canine parvovirus (CPV), Leptospira canicola, Leptospira grippotyphosa, Leptospira icterohaemorrhagiae and Leptospira pomona."

Claim 1 of auxiliary request 1 differs from claim 1 of the main request in that the disclaimer "without containing Bordetella bronchiseptica p68 antigen" is added at the end of the claim.

Claim 1 of auxiliary request 2 reads as follows:

"1. A vaccine composition for use in protecting dogs against infection caused by Leptospira bratislava comprising a Leptospira cell preparation of Leptospira bratislava, Leptospira canicola, Leptospira grippotyphosa, Leptospira icterohaemorrhagiae and Leptospira pomona, and an attenuated strain of canine distemper (CD) virus, an attenuated strain of canine adenovirus type 2 (CAV-2), an attenuated strain of canine parainfluenza (CPI) virus, an attenuated strain of canine parvovirus (CPV), an inactivated preparation of the canine coronavirus (CCV) strain, and a carrier."

Claim 1 of auxiliary request 3 differs from claim 1 of the auxiliary request 2 in that the disclaimer "without containing Bordetella bronchiseptica p68 antigen" is added at the end of the claim.

Annex(es): | |

VII. Both respondents filed a reply to the appellant's statement of grounds of appeal.

VIII. With letter dated 29 September 2022, the appellant submitted sets of claims of auxiliary requests 2a and 3a.

IX. Respondent II made further submissions with letter dated 19 December 2022 and again by letter dated 29 January 2024, where it raised a new added subject-matter objection against claim 1 of the main request and all auxiliary requests on file. It submitted that the application as filed did not disclose a combination vaccine for use in protecting dogs against infections caused specifically by Leptospira bratislava.

X. In response, with letter dated 14 February 2024, the appellant submitted sets of claims of auxiliary requests 4, 5, 6, 7, 8 and 9 corresponding to the main request, auxiliary requests 1, 2, 2a, 3 and 3a, respectively, with claim 1 amended to define that the vaccine composition is for use in protecting dogs against disease caused by Leptospira bratislava.

Claim 1 of auxiliary request 4 thus reads (amendments compared to claim 1 of the main request are shown by strikethrough and underlining):

"1. A vaccine composition for use in protecting dogs against [deleted: infection] disease caused by Leptospira bratislava comprising a Leptospira cell preparation of Leptospira bratislava and a carrier, and further comprising one or more antigens of another canine pathogen, selected from the group consisting of canine distemper (CD) virus, canine adenovirus type 2 (CAV-2), canine parainfluenza (CPI) virus, canine coronavirus (CCV), canine parvovirus (CPV), Leptospira canicola, Leptospira grippotyphosa, Leptospira icterohaemorrhagiae and Leptospira pomona."

XI. The board scheduled oral proceedings, as requested by the parties and issued a communication under Article 15(1) RPBA setting out its preliminary opinion on some matters concerning the appeal.

XII. With a letter dated 10 July 2024, respondent II submitted document D89.

XIII. Oral proceedings took place as scheduled. At the end of the oral proceedings the chairwoman announced the board's decision.

XIV. The decision refers to the following documents:

D1 US 5,000,951 (19 March 1991)

D3 Prescott J.F. et al., Can Vet J (1991), vol. 32,

pages 481 to 486

D4 Rentko V.T. et al., Journal of Veterinary

Internal Medicine (1992), vol. 6, pages 235 to

244

D5 Harkin K.R. and Gartrell C.L., Journal of the

American Animal Hospital Association (1996),

vol. 32, pages 495 to 501

D8 Birnbaum N. et al., Journal of Small Animal

Practice (1998), vol. 39, pages 231 to 236

D10 Tronel J.P. et al., Canine Infectious Diseases:

From Clinics to Molecular Pathogenesis,

Carmichael L. (Ed.) (1999), page 1

D12 Drs. Foster and Smith Educational Staff, March

2000 News, page 1

D13 Adin C.A. and Cowgill L.D., J Am Vet Med Assoc

(2000), vol. 216, pages 371 to 375

D14 Schultz R.D., Recent Advances in Canine

Infectious diseases, Carmichael L.E. (Ed.)

(2000), pages 1 to 9

D15 Gueguen S. et al., Anclivepa Congress Rio

Brazil (9 June 2000), poster, pages 1 to 16

D16 Davol P.A., Canine Leptospirosis (2001),

www.labbies.com/lepto.t1m, pages 1 to 3

D19 WO 03/24354 (27 March 2003)

D20 Klaasen H.L.B.M. et al., Veterinary Microbiology

(2003), vol. 95, pages 121 to 132

D25 WO 2004/067031 (12 August 2004)

D27 Ribotta M.J. et al., The Canadian Journal of

Veterinary Research (2000), vol. 64, pages 32

to 37

D28 Scanziani E. et al., Journal of Small Animal

Practice (2002), vol. 43, pages 154 to 157

D29 Prescott J.F. et al., Can Vet J (2002), vol. 43,

pages 955 to 961

D31 Burriel A.R. et al., Veterinary Record (2003),

vol. 153, pages 146 to 148

D36 Mandell G.L, Bennett J.E. and Dolin R.,

Principles and Practice of Infectious Diseases

(2005), pages 2789 to 2795

D37 The Center for Food Security & Public Health

(2005), fact sheet Leptospirosis

D41 Emerging Diseases of Animals, Brown C. and

C. Bolin (Eds.) (2000), pages 184 to 189

D42 Product Guide Intervet (2002), pages 161, 164

and 167

D43 White C.J. et al., Clinical Infectious Diseases

(1997), vol. 24, pages 925 to 931

D44 Kanesa-thasan N. et al., Vaccine (2001),

vol. 19, pages 3179 to 3188

D45 Center for Veterinary Biologics Notice

No. 05-06 (24 February 2005), page 1 to 2

D46 Greenlee J.J. et al., AJVR (October 2005),

pages 1816 to 1822

D47 Andr -Fontaine G. et al., The Veterinary Record

(2003), vol. 153, pages 165 to 169

D51 Spier R.E., Folia Microbiol. (1997), vol. 42,

pages 105 to 112

D56 Faine S., Leptospira and Leptospirosis (1994),

pages 174 to 184

D62 Levett P.N., Clinical Microbiology Reviews

(2001), vol. 14, pages 296 to 326

D64 Handbook of Zoonoses, Beran G.W. (Ed.) (1994),

second edition, pages 245 to 263

D79 Sutton D., Veterinary Nursing (2003), vol. 18,

pages 56 to 62

D86 US 6,368,603 (9 April 2022)

D87 US 2004/0202668 (14 October 2004)

D88 US 2014/0186393 (3 July 2014)

XV. In relation to documents D56a, D68, D69, D70, D71, D72, D74, D75, D77, D78, D81, D82, D83, D84, D85 and D89 no decision on their admittance had to be taken. The board arrived at its conclusions without taking these documents into account.

XVI. The appellant's arguments relevant to this decision are summarised below.

Exclusion from the proceedings of the main request and auxiliary requests 1, 2 and 3

The opposition division had admitted the main request and auxiliary requests 1 to 3 into the proceedings and the decision under appeal was based on these requests. They were therefore in the appeal proceedings.

Admittance and consideration of documents D86, D87 and D88 (Article 12(4) RPBA)

Admittance of documents D86, D87 and D88 into the appeal proceedings was left to the board.

Main request

Inventive step - claim 1

Closest prior art

Document D25 only provided efficacy data for a vaccine comprising L. canicola and L. icterohaemorrhagiae (see Example 4) and mentioned L. bratislava merely in passing. The disclosure as to L. bratislava in

document D25 (see page 3, lines 18 to 28) was speculative without any sound scientific basis. Selecting this disclosure as the closest prior art involved an unallowable ex post facto analysis.

The composition disclosed in Example 4 of document D25 was the closest prior art.

Difference(s), technical effect, objective technical problem

The distinguishing features between the composition disclosed in Example 4 of document D25 and the claimed subject-matter were that (i) the vaccine composition comprised L. bratislava, (ii) that it provided protection against disease by L. bratislava and (iii) that it provided protection against infection caused by L. bratislava.

The objective technical problem proposed by the respondents recited the solution and was not correct. Considering that a newly developed vaccine had to be capable of conferring protection against a further pathogen, reciting said pathogen in the objective technical problem already presupposed knowledge of the invention, i.e. that it was possible to generate a protective effect against this pathogen. Formulating the problem as the provision of a vaccine against

L. bratislava amounted to a selection from the list of pathogens on page 3, lines 18 to 28 of document D25 using hindsight knowledge.

Starting from the composition disclosed in Example 4 of document D25, the objective technical problem was the provision of a vaccine composition which provided protection of dogs against infection and disease caused by a further Leptospira serovar and possibly other canine pathogens.

Obviousness

The skilled person would not have modified the vaccine composition of Example 4 of document D25 to add L. bratislava and would not have had a reasonable expectation of success when trying to generate a combination vaccine against L. bratislava.

Earlier decision T 148/15 and its binding effect (Article 111(2) EPC)

The opposition division's conclusion on efficacy interference was inconsistent with the board's decision in T 148/15. How document D25 was read and the ratio decidendi of T 148/15 was binding and deprived the skilled person of any reasonable expectation of success.

Efficacy interference was a well-known problem in the development of combination vaccines

The opposition division's conclusion that the well-known problem of efficacy interference (as discussed in document D25) would not have deprived the skilled person of a reasonable expectation of success was wrong. Documents D25, D43, D44, D51 and D79 provided evidence that efficacy interference was a well-known problem in the development of combination vaccines which made the development of combination vaccines unpredictable per se.

The opposition division was wrong to conclude that the skilled person would have had a reasonable expectation of success in view of the vaccines against other Leptospira serovars on the market. Firstly, given that these vaccines were on the market, they had been tested beforehand as to their efficacy and whether there was a problem with efficacy interference. Secondly, even if the existing vaccines against other Leptospira serovars were efficacious, the skilled person did not know whether a combination vaccine could protect dogs against infection with L. bratislava, see also T 148/15 (Reasons 46).

That there was no evidence of failure in commercial vaccines due to efficacy interference was irrelevant because none of the commercial vaccines contained

L. bratislava.

The respondents referred to an enormous number of documents but did not point out which combination of documents would render the claimed subject-matter obvious.

Document D64 was from 1994 and thus outdated. The statement on page 261, first full paragraph, did not relate to dogs.

Document D28 merely stated that polyvalent bacterins could be useful, without any evidence to this effect.

The following additional factors would have deprived the person skilled in the art from a reasonable expectation of success.

The generation of vaccines was generally unpredictable

Documents D43 and D44 provided evidence that vaccine generation was generally unpredictable. Based on the disclosure and exemplification in document D25, the skilled person had no reasonable expectation of success when preparing a vaccine against L. bratislava. Document D14, a review article, reported that there was a concern regarding the vaccines' efficacy, because a high percentage of vaccinated dogs did not develop protective immunity or they developed immunity for only a short duration of time (page 7, lines 3 to 10). The immune response in dogs to Leptospira bacterins was in any case known not to be very pronounced (page 7, lines 4 to 5).

The basic premise in vaccine development was that one did not know beforehand whether or not a given antigen or bacterin would elicit a protective immune response.

L. bratislava was not perceived as an emerging source for leptospirosis in dogs

There was no motivation to provide a vaccine against infection with L. bratislava because L. bratislava was not perceived as an emerging source for leptospirosis in dogs. Consequently, there was also no reasonable expectation of success that vaccination against L. bratislava would be effective in treating or protecting dogs against leptospirosis.

The picture at the effective date was mixed with regard to the predominant serovars in dogs and prevalence seemed to be strongly depended on the geographic area (see documents D3, D4, D5, D8, D13, D16, D27, D28, D29, D31, D37, D41). These documents did not teach the skilled person that L. bratislava had been detected in dogs as causative agent for leptospirosis. Rather, L. bratislava was mentioned based on positive serology using an MAT test.

Document D36, a textbook, taught that the MAT was a serogroup-specific assay, and could not be used to interpret the identity of the infecting serovar (see page 2793, left hand column, second paragraph).

Document D45 could be considered to reflect the common general knowledge before the effective date. It provided evidence that it was not established at the effective date that L. bratislava was a significant pathogen in dogs (page 1, third paragraph). It also criticised that the data supporting the theory that L. bratislava was a significant pathogen [in the US] was based on serology.

The statement on page 189 of document D41 was not supported by any data or evidence that L. bratislava caused disease in dogs.

While document D28 stated (at page 157, middle column, 1st paragraph) that in cases with multiple serovar titres, the higher titre was considered the infecting serovar, it nowhere stated that this would also identify the aetiologic serovar. Yet, this was exactly the information the skilled person would need before considering the generation of a vaccine.

There was no challenge model available and the development of such a model was not straight forward

Document D46 provided evidence that the leading experts in the field had real-world problems when trying to infect dogs with L. bratislava. The skilled person could not have tested a potential vaccine without generating a challenge model first.

Try and see

The skilled person was not in a try and see situation and would not have adopted a try and see attitude.

Auxiliary requests 1, 2 and 3

Article 56 EPC

The same arguments applied as for the main request.

Auxiliary request 4

Admittance and consideration

In case the board's decision on inventive step turned on the wording in claim 1 of the main request this would represent a new line of argument, made for the first time at the oral proceedings. In the written phase, it had not been said that protecting against infection was not enough, disease needed to be prevented. This represented exceptional circumstances, justified with cogent reasons for the admittance of auxiliary request 4 under Article 13(2) RPBA. The arguments on inventive step, in particular those on non-obviousness were the same as those presented for the main request.

XVII. The respondents' arguments relevant to this decision are summarised below.

Exclusion from the proceedings of the main request and auxiliary requests 1, 2 and 3

The main request and auxiliary requests 1, 2 and 3 should not have been admitted into the opposition proceedings and should not be admitted into the appeal proceedings.

Main request

Inventive step - claim 1

Closest prior art

The disclosure relating to a combination vaccine comprising an inactivated whole cell preparation of L. bratislava in document D25 was the closest prior art. Document D25 disclosed where to obtain the L. bratislava serovar (page 12, lines 12 to 17), a combination vaccine comprising L. bratislava was disclosed as a preferred embodiment on multiple occasions (page 3, lines 33 to 38; page 4, lines 7 to 11, page 5, lines 16 to 21 and 28 to 31; page 12, lines 10 to 23; page 13, lines 10 to 13) and document D25 provided enough information for the skilled person to make and test such a vaccine.

Difference(s), technical effect, objective technical problem

The only distinguishing feature between the disclosure in document D25 and the claimed subject-matter was the therapeutic effect of protecting dogs against infection caused by L. bratislava. The claim did not recite protection from disease and did not require protection against any other canine pathogen.

The objective technical problem should be directed to provision of protection against L. bratislava infection specifically because the closest prior art was a combination vaccine that comprised L. bratislava.

The objective technical problem was the provision of a vaccine for use in protecting dogs against infection caused by L. bratislava.

Obviousness

Earlier decision T 148/15 and its binding effect (Article 111(2) EPC)

The board's findings with respect to novelty in

T 148/15 were not equally applicable to the assessment of inventive step since the tests for determining novelty and inventive step were different.

For the claimed invention to lack an inventive step there simply needed to be a reasonable expectation that the vaccine disclosed in document D25 would provide effective protection in dogs against L. bratislava.

Efficacy interference was a well-known problem in the development of combination vaccines

It was not denied that efficacy interference - in the general sense - was a consideration for the skilled person when developing combination vaccines.

Documents D25, D43, D44, D51, D79 provided no technical evidence that efficacy interference was a real problem in the field of multivalent, canine, Leptospira vaccines.

The existence of several, successful, multivalent canine Leptospira bacterin vaccines that successfully protected dogs against leptospirosis belonged to the common general knowledge, see documents D1, D10, D13, D15, D19, D20, D25, D28, D42, D47, D62.

For the additional antigens recited in the claim, commercial vaccines were on the market, see at least documents D10, D12, D13, D15, D16, D19, D20, D25, D28, D42, D47, D62. These had been tested and their efficacy had been shown. Thus at least for these viral antigens and Leptospira serovars, efficacy interference was not expected.

Evidence of common general knowledge could be derived from the sheer number of disclosures of a certain fact or event.

Document D64, a textbook, provided further evidence (page 261, first full paragraph) that efficacy interference not being a cause for concern in the Leptospira field of vaccine development belonged to the skilled person's common general knowledge. Document D64 disclosed that leptospirosis in dogs was a common occurrence, that dogs could be infected by all known serovars (page 254 first paragraph) and that various preparations of bacterins were available for preventive vaccination procedures (page 254, last sentence of third paragraph). The teaching of document D64 was not outdated. It had been confirmed by the various multivalent Leptospira combination vaccines developed in the art. Nothing in the proceedings indicated that dogs reacted differently to L. bratislava than other animals.

There was nothing in the prior art that would show that L. bratislava behaved differently from other known Leptospira serovars that were already present in commercially available vaccines together with the other known and claimed viral canine antigens. Hence, the skilled person would have had every expectation of success that a cell preparation of L. bratislava in a multivalent vaccine would provide protection in dogs against a L. bratislava infection.

In view of the plethora of commercially-available, effective, multivalent, canine Leptospira vaccines in the art - and no evidence of failure of any of them due to efficacy interference - the skilled person, starting with the vaccine disclosed in document D25 comprising L. bratislava and seeking to provide a vaccine for protecting dogs against infection with L. bratislava, would have considered there to be more than a reasonable expectation that administering this vaccine to canines would result in effective protection.

The generation of vaccines was generally unpredictable

Document D25 did not support the appellant's case that the generation of vaccines was inherently un-predictable. Document D25 disclosed that a multivalent Leptospira vaccine protected dogs against infection caused by L. canicola and L. icterohaemorrhagiae infection (example 4) and thus provided evidence of success in developing multivalent canine Leptospira vaccines.

Document D14 did not support the appellant's case either. Document D14 had been misinterpreted by the appellant. The reason the dogs had failed to develop immunity was not because the vaccine did not protect against the particular serovars which it contained, but because the vaccine did not cross-protect against other prevalent serovars in the field. Document D14 actually showed that combination vaccines were known and were known to work in dogs and were used by veterinarians. Document D14 in no way diminished the skilled person's expectation that a L. bratislava bacterin would protect against L. bratislava infection.

It was common general knowledge that protection against Leptospira infection was serovar specific, i.e. that a vaccine against one serovar did not protect against another serovar (document D62, page 306, last sentence).

Due to the manifold success in developing multivalent canine Leptospira vaccines in the art, the skilled person would not have perceived any particular unpredictability in this particular field.

That there was no reason to doubt that a bacterin comprising a cell preparation of L. bratislava would work was confirmed by documents D3, D13 and D28. The art motivated the skilled person to add L. bratislava to existing vaccines and to expect protection to ensue.

Document D56 emphasised the common general knowledge in the art as to how leptospiral vaccines were produced: one simply added another serovar to increase the breadth of protection according to the local prevalence (page 175, second paragraph). The expectation in the art was that such a vaccine would provide protection.

L. bratislava was not perceived as an emerging source for leptospirosis in dogs

The skilled person's motivation to include

L. bratislava in a multivalent canine vaccine was an irrelevant consideration for this appeal. The closest prior art already disclosed a vaccine that comprised

L. bratislava.

Document D41, a textbook reference and hence indicative of common general knowledge disclosed that

L. bratislava was considered as a common cause for leptospirosis in dogs. It was normal that a textbook contained no data.

Document D28 disclosed that L. bratislava was emerging in Europe and was responsible for symptomatic leptospirosis in dogs. In addition, document D28 also indicated that vaccination was the choice in prevention of leptospirosis (page 157, middle column lines 11 to 12).

Prior to the priority date, i.e. the effective date of the patent, it was common general knowledge that incidence of canine infection with L. bratislava was increasing, and that protection against Leptospira infection was serovar-specific. Thus, the skilled person would have known that they needed to include an L. bratislava serovar antigenic constituent in a vaccine in order to protect dogs from infection with this serovar.

Document D45 was published after the effective date of the patent and thus was not prior art. Furthermore document D45 related only to the situation in the United States, whereas many of the other documents which identify L. bratislava as a key pathogen concerned Europe and Canada, e.g. document D28, which in contrast to D45 was publicly available at the effective date of the patent.

There was no challenge model available and the development of such a model was not straight forward

The existence (or absence) of a challenge model did not affect the skilled person's reasonable expectation that a vaccine would have a therapeutic effect. Document D46 was not prior art.

The subject-matter of claim 1 lacked an inventive step.

Try and see

The skilled person was in a try and see situation, but the claimed subject-matter also lacked inventive step in accordance with the case law relating to considerations of reasonable expectation of success.

Auxiliary requests 1, 2 and 3

The same arguments applied as for the main request.

Auxiliary request 4

Admittance and consideration (Article 13(2) RPBA)

The scenario which, in the appellant's view, served as a justification for the late submission of this claim request had been concocted by the appellant, in view of its interpretation of document D28 during the oral proceedings. For the assessment of inventive step, it made no difference whether the claim was directed to protection against infection or disease. The same arguments applied as for the main request.

XVIII. The appellant requested:

- that the decision under appeal be set aside and the patent be maintained in amended form on the basis of the set of claims of the main request, or alternatively, on the basis of the set of claims of one of auxiliary requests 1, 2 or 3.

The appellant further requested:

- that documents D86, D87 and D88 be admitted into the appeal proceedings;

- that documents D56a, D68, D69, D70, D71, D72, D74, D75, D77, D78, D81, D82, D83, D84, D85 and D89 not be admitted into the appeal proceedings;

- that respondent I's insufficiency objections filed in reply to the appeal with letter dated 13 April 2022, not be admitted into the appeal proceedings;

- that respondent I's added subject-matter objection against the main request and auxiliary request 3, filed in reply to the appeal with letter dated 13 April 2022, not be admitted into the appeal proceedings;

- that respondent II's new lack of clarity objection in view of the expression "one or more antigens of another canine pathogen" against the main request and auxiliary request 1 or the term "'the' CCV" against auxiliary requests 2 and 3, both objections filed in reply to the appeal with letter dated 6 April 2022, not be admitted into the appeal proceedings;

- that respondent II's new added subject-matter objection against the main request and auxiliary request 2 in view of the use of product and medical use language filed in reply to the appeal with letter dated 6 April 2022, not be admitted into the appeal proceedings;

- that, should the board admit respondent II's new clarity objection against auxiliary request 2 and added subject-matter objections against auxiliary requests 2 and 3 in view of the term '"the" CCV strain' into the proceedings, auxiliary requests 2a and 3a be admitted into the appeal proceedings;

- that respondent II's new sufficiency objections filed in reply to the appeal with letter dated 6 April 2022, not be admitted into the appeal proceedings;

- that respondent II's request not to admit the main request and auxiliary requests 1 to 3 into the appeal proceedings be disregarded for lack of a legal basis;

- that the case not be remitted to the opposition division for consideration of sufficiency of disclosure and that sufficiency of disclosure be considered and decided upon by the board;

- that, should the board admit respondent II's new added subject-matter objection against the main request and auxiliary requests 1, 2, 3, 2a and 3a, filed with letter dated 19 December 2022, auxiliary requests 4 to 9 be admitted into the appeal proceedings.

Respondent I requested:

- that the appeal be dismissed and

- that documents D56a, D84, D85 be admitted into the appeal proceedings.

Respondent II requested:

- that the appeal be dismissed and

- that the main request and auxiliary requests 1, 2 and 3 not be admitted into the appeal proceedings;

- that documents D86, D87 and D88 not be admitted into the appeal proceedings;

- that the case be remitted to the opposition division for discussion of Article 83 EPC in the event that the board sets aside the decision under appeal;

- that document D89, submitted with the letter dated 10 July 2024, be admitted into the appeal proceedings.

Reasons for the Decision

Exclusion from the proceedings of the main request and auxiliary requests 1, 2 and 3

1. Respondent II submitted that the main request and auxiliary request 2, which were filed as auxiliary requests 8 and 9 on 27 April 2021, i.e. after the final date for making written submissions and/or amendments fixed by the opposition division under Rule 116 EPC, should not have been admitted into the proceedings by the opposition division and should not be admitted into the appeal proceedings either. Respondent II also submitted that auxiliary requests 1 and 3, which were filed as auxiliary requests 12 and 13 on 10 December 2018 and then re-filed in amended form as auxiliary requests 6 and 7 on 26 March 2021, the final date for making written submissions and/or amendments fixed by the opposition division under Rule 116 EPC, should not have been admitted into the proceedings by the opposition division and should not be admitted into the appeal proceedings either.

2. The opposition division had admitted the main request and auxiliary requests 1, 2 and 3 into the proceedings and these claim requests were considered in the impugned decision on substance. Thus, the decision under appeal is based on these claim requests and they form part of the appeal proceedings (Article 12(1)(a) and 12(2) RPBA). The EPC does not provide any legal basis for excluding these requests from the appeal proceedings (see also CLBA, V.A.3.4.4). The board's reviewing of the opposition division's decision on the admittance of these claim requests was also not required against the background that neither respondent claimed that an infringement of its right to be heard was associated with the admission.

Admittance and consideration of documents D86, D87 and D88

Article 12(4) RPBA

3. In view of the primary object of the appeal proceedings to review the decision under appeal in a judicial manner, a party's appeal case shall be directed to the requests, facts, objections, arguments and evidence on which the decision under appeal was based

(Article 12(2) RPBA).

4. Under Article 12(4) RPBA, any part of a party's appeal case which does not meet the requirements in Article 12(2) RPBA is to be regarded as an amendment, unless the party demonstrates that this part was admissibly raised and maintained in the proceedings leading to the decision under appeal.

5. The appellant submitted documents D86, D87 and D88 on 27 April 2021, one month after the final date for making written submissions and/or amendments set by the opposition division under Rule 116 EPC.

6. In the communication issued under Article 15(1) RPBA, the board observed that (i) it appeared that the decision under appeal was not based on any of documents D86, D87 and D88 (Article 12(2) RPBA) and (ii) that the appellant had not demonstrated that documents D86, D87 and D88 were admissibly raised and maintained in the proceedings leading to the decision under appeal (Article 12(4) RPBA). The board therefore provisionally considered the appellant's case, to the extent that it was based on any of these documents, as an amendment.

7. This was not disputed by the appellant in writing or during oral proceedings before the board. When asked during oral proceedings before the board, the appellant submitted that it would not rely on any of documents D86, D87 and D88, made no submissions on the subject of the admittance of these documents and stated that it left the issue of their admittance for the board's decision.

8. In these circumstances, the board considered the appellant's case to the extent that it was based on any of these documents an amendment within the meaning of Article 12(4) RPBA.

9. Any such amendment may be admitted only at the discretion of the board (Article 12(4) RPBA).

According to Article 12(4) RPBA, the party shall provide reasons for submitting the amendment in the appeal proceedings. Since the appellant had not complied with that requirement the board saw no reason to admit documents D86, D87 and D88 into the appeal proceedings.

Main request

Inventive step (Article 56 EPC) - claim 1

Closest prior art

10. Claim 1 is drafted as a purpose-limited product claim in accordance with Article 54(5) EPC. The product is a vaccine composition containing Leptospira bratislava (L. bratislava) and at least one antigen of another canine pathogen specified in the claim, which can be a further Leptospira serovar or a virus. The therapeutic purpose is protecting dogs against infection caused by L. bratislava while protection against any other canine pathogen is not required (for the complete wording of the claim see section VI. above).

11. The opposition division considered that the disclosure relating to a combination vaccine comprising a cell preparation of L. bratislava in document D25 was the closest prior art. On appeal, the appellant contended that the disclosure in Example 4 of document D25 should instead be taken as the starting point for the assessment of inventive step.

12. Document D25 relates to combination vaccines containing a Bordetella bronchiseptica (B. bronchiseptica) p68 antigen and one or more antigens of another canine pathogen and to methods for protecting dogs against diseases caused by such other canine pathogens by using these combination vaccines (see page 1, lines 6 to 14; page 3, lines 18 to 22). An especially preferred combination vaccine of document D25 is a combination vaccine which comprises a inactivated whole cell preparation of L. bratislava, antigens of all other canine pathogens recited in claim 1 of the main request and a B. bronchiseptica antigen p68 (page 4, lines 7 to 11; page 5, lines 16 to 21; page 12, lines 10 to 27; page 13, lines 10 to 13; claim 9). While document D25 also provides enough information for the skilled person to make the combination vaccine and to administer it to dogs (page 12, lines 10 to 27), document D25 does not directly and unambiguously disclose that such a combination vaccine achieves the therapeutic effect of protecting dogs against infection by L. bratislava (see also T 148/15, Reasons 49).

13. Document D25 furthermore discloses VANGUARD**( ) Plus 5/CV-L, a combination vaccine which includes antigens of the five viruses recited in claim 1 as well as inactivated whole cultures of the two Leptospira serovars icterohaemorrhagiae and canicola but not bratislava (Example 4). For this combination vaccine, document D25 discloses that it "immunized dogs against CD, ICH, CAV-2 and CPI respiratory disease, enteritis caused by CCV and CPV, and leptospirosis caused by L. canicola and L. icterohaemorrhagiae, and that no immunologic interference existed among the vaccine fractions" (page 53, lines 12 to 15).

14. In accordance with the established case law of the boards of appeal, the closest prior art for assessing inventive step is normally a prior art disclosing subject-matter conceived for the same purpose or having the same objective as the claimed invention and having the most relevant technical features in common, i.e. requiring the minimum of structural modifications (see CLBA, section I.D.3.1).

15. The purpose or objective of a purpose-limited product claim under Article 54(5) EPC is, generally, the therapeutic indication recited in the claim. In the case at hand, this is protecting dogs against infection caused by L. bratislava (see point 10. above). This is the purpose of the claimed invention.

16. The purpose of the combination vaccines disclosed in document D25 is to induce a protective immune response in dogs against diseases caused by the antigens from the canine pathogens contained in the combination vaccines (see document D25, page 3, lines 18 to 22).

17. In agreement with the decision under appeal and the respondents, the board holds that, based on shared purpose and structural features, the disclosure in document D25 relating to the combination vaccine comprising a cell preparation of L. bratislava is the closest prior art.

18. By contrast, VANGUARD**( ) Plus 5/CV-L does not comprise an antigen from L. bratislava and is therefore not designed for the purpose of protecting dogs against infection caused by L. bratislava, the purpose as the claimed invention, nor does it have the most relevant technical features in common. That document D25 provides efficacy data for VANGUARD**( ) Plus 5/CV-L but not for the combination vaccine comprising a cell preparation of L. bratislava, is irrelevant to the selection of the closest prior art according to the problem and solution approach.

19. Contrary to the appellant's view, the disclosure in document D25 regarding L. bratislava is neither speculative nor without scientific basis. L. bratislava is mentioned not only on page 3, lines 22 to 28 of document D25, but on several occasions (see point 12. above); the combination vaccine containing L. bratislava is a preferred embodiment of document D25 (ibid.) and it can be generated and administered to dogs on the basis of the information provided in document D25 (ibid.).

20. Since the selection of the closest prior art is based on same purpose and shared structural features (point 14. above) it necessarily requires consideration of the claimed invention. The board therefore does not share the appellant's view that the selection of the combination vaccine containing L. bratislava involves an inadmissible ex post facto analysis.

Difference(s), technical effect, objective technical problem

21. The technical effect(s) used to formulate the objective technical problem are based on features that distinguish the claimed invention from the closest prior art.

22. As set out above (point 17. above) the closest prior art is document D25's disclosure relating to a combination vaccine that contains a cell preparation of L. bratislava.

23. The claimed subject-matter differs from the closest prior art only in that the therapeutic effect of protecting dogs against infection by L. bratislava is achieved.

24. Contrary to the appellant's arguments based on

example 4 of document D25 as the starting point for assessing inventive step, L. bratislava is not a feature which distinguishes the claimed invention from the closest prior art.

25. Claim 1 does not mention protection against disease caused by L. bratislava. Therefore, this is not a distinguishing feature either.

26. The technical effect linked to the sole difference is that the combination vaccine is effective in protecting dogs against infection by L. bratislava.

27. Protection against canine pathogens other than

L. bratislava is not a technical effect resulting from the sole distinguishing feature and therefore does not need to be taken into account in the formulation of the objective technical problem, contrary to the view taken by the appellant.

28. Since the closest prior art is a combination vaccine that already comprises L. bratislava, and it is merely the resulting therapeutic effect - and not the inclusion of the L. bratislava constituent per se - that is the distinguishing feature, the objective technical problem cannot be formulated as the provision of protection against "further" Leptospira serovars, contrary to the view taken by the appellant.

29. For these reasons, the objective technical problem to be solved by the claimed subject-matter is the provision of an effective vaccine for use in protecting dogs against infection by L. bratislava.

30. The combination vaccine containing a cell preparation of L. bratislava has a defined composition (see point 12. above). Contrary to the appellant's view, therefore the formulation of the problem as the provision of a vaccine against L. bratislava does not involve a selection from the list of pathogens on page 3, lines 18 to 28, of document D25 using hindsight knowledge.

31. It was undisputed that the claimed subject-matter provides a solution to the objective technical problem.

Obviousness of the claimed solution

32. The parties were in dispute whether the skilled person starting from the closest prior art and seeking a solution to the objective technical problem formulated above would, in view of the closest prior art, possibly in combination with other prior art or common general knowledge, have arrived at the claimed invention.

33. The appellant's argument that the skilled person would not have modified the vaccine composition of Example 4 of document D25 to include L. bratislava must be rejected because Example 4 is not the closest prior art.

34. As set out in point 12. above, document D25 discloses the combination vaccine which includes an inactivated cell preparation of L. bratislava together with antigens of all other canine pathogens recited in claim 1 of the main request and a B. bronchiseptica antigen p68 and its use for protecting dogs against diseases caused by any of these canine pathogens, including L. bratislava (see also T 148/15,

Reasons 29).

35. Document D25 therefore already suggested the use of a multivalent combination vaccine containing an inactivated cell preparation of L. bratislava in dogs as a solution to the objective technical problem formulated above.

36. The board recalls that in order to render a solution obvious it is not necessary to establish that the success of an envisaged solution of a technical problem was predictable with certainty. It is sufficient to establish that the skilled person would have followed the teaching of the prior art with a reasonable expectation of success (CLBA, I.D.7.1).

37. The assessment of the skilled person's expectation of success requires a scientific evaluation of the facts of the case based on the information available at the relevant date, including teachings from prior art documents other than the closest prior art and the common general knowledge.

38. Therefore, it is relevant to consider whether, at the effective date, the skilled person would have reasonably expected that the combination vaccine containing an inactivated cell preparation of

L. bratislava disclosed in document D25 would be effective in protecting dogs against infection with

L. bratislava.

39. The opposition division found that this was the case, essentially for the following reasons.

39.1 Firstly, while the opposition division acknowledged that the passage on page 2, lines 29 to 38 of

document D25 was sufficient to not completely exclude a potential efficacy interference and thus could raise doubts that the combination vaccine disclosed in document D25 could provide a protective effect with absolute certainty, it dismissed the appellant's argument that this passage would have deprived the skilled person of a reasonable expectation of success that the combination vaccine disclosed in document D25 could protect against L. bratislava infection (decision under appeal, page 7, last paragraph to page 8, second paragraph).

39.2 Secondly, the opposition division found that the skilled person, after having analysed the situation of closely related combination vaccines for dogs comprising the same attenuated viruses as mentioned in claim 1 and up to four other Leptospira serovars without antigenic interference, would have had a reasonable expectation that the combination vaccine as disclosed in document D25 was effective for the treatment and prevention of infection with L. bratislava (decision under appeal, page 8, penultimate paragraph to page 9, last paragraph).

40. These findings were contested by the appellant. It submitted that the opposition division's conclusion that the well-known problem of efficacy interference would not have deprived the skilled person of a reasonable expectation of success was wrong and also inconsistent with the board's decision in T 148/15.

Earlier decision T 148/15 and its binding effect

(Article 111(2) EPC)

41. As set out above (section V.) the present case constitutes the second appeal concerning the patent in suit. In case of a remittal to the department whose decision was appealed, that department is bound by the ratio decidendi of the board of appeal, in so far as the facts are the same (Article 111(2) EPC). Moreover, in accordance with established case law of the boards of appeal, the same applies to a board in second appeal proceedings who is bound by the ratio decidendi of the earlier board decision in so far as the facts are the same (CLBA, V.A.10.4).

42. The binding effect extends to any finding of fact that led to this decision. However, the opposition division - and the board - are bound only in so far as the facts are the same and only in so far as the legal assessment is the same.

43. In decision T 148/15, novelty over document D25 was at issue and hence whether document D25 directly and unambiguously disclosed that a combination vaccine, comprising L. bratislava amongst other canine pathogens, achieved the claimed therapeutic effect, i.e. protection of dogs against infection caused by L. bratislava (T 148/15, Reasons 48, 49). The board noted the absence of any data showing that the use of such a multivalent combination vaccine in dogs protected them against infection caused by L. bratislava (T 148/15, Reasons 31), acknowledged that efficacy interference was also a problem in dogs (T 148/15, Reasons 41, 45) and concluded that the skilled person would have had at least some doubts that the combination vaccine could indeed protect dogs against infection caused by L. bratislava (T 148/15, Reasons 43). The board also held that the existence of effective combination vaccines against other leptospira serovars did not allow any conclusion as regards the protective effect provided by the multivalent vaccine disclosed in document D25 (T 148/15, Reasons 46).

44. The board found that the doubts that the skilled person would have had as to the protective effect of a combination vaccine containing L. bratislava, meant "that document D25 does not directly and unambiguously disclose that a combination vaccine, comprising L. bratislava amongst other canine pathogens, achieves the claimed therapeutic effect, i.e. protection of dogs against infection caused by L. bratislava" (T 148/15, Reasons 49).

45. For the claimed invention to lack an inventive step, the therapeutic effect of protection of dogs against infection caused by L. bratislava need not be directly and unambiguously derivable from document D25 alone. Rather, there only must have been a reasonable expectation for the skilled person that the combination vaccine disclosed in document D25 would provide effective protection against infection with L. bratislava when administered to dogs. Certainty is not a criterion for assessing a reasonable expectation of success.

46. Thus, contrary to the appellant's assertion, the doubts which the board found in decision T 148/15 that the skilled person would have had as to the protective effect of a combination vaccine containing L. bratislava on the basis of document D25 do not directly translate into a lack of expectation of success.

47. In addition, teachings from other prior art documents and the common general knowledge may be taken into account in assessing the skilled person's reasonable expectation of success. Therefore, the opposition division was not limited to the teachings of

document D25 in its assessment of the skilled person's reasonable expectation of success.

48. The appellant's argument that the opposition division's conclusion regarding a reasonable expectation of success (points 39.1 and 39.2 above) was inconsistent with the board's decision in case T 148/15 must therefore be rejected.

Efficacy interference was a well-known problem in the development of combination vaccines

49. The appellant did not dispute the opposition division's findings that (i) document D25 wrongly implied that there were no combination vaccines for dogs and (ii) that it was not common knowledge that there was a peculiarity of the canine immune system (decision under appeal, page 8, first full paragraph).

50. The appellant maintained however that documents D25, D43, D44, D51 and D79 provided evidence that efficacy interference was a well-known problem in the development of combination vaccines which made the development of combination vaccines per se unpredictable and that the opposition division's conclusion that the well-known problem of efficacy interference (as discussed in D25) would not have deprived the skilled person of a reasonable expectation of success was therefore wrong.

51. However, that efficacy interference in the general sense - i.e. a failure of one or more antigens in a combination vaccine to maintain or achieve efficacy due to the presence of the other antigens in the vaccine - was a consideration for the skilled person when developing combination vaccines was not denied in the decision under appeal or by the respondents on appeal.

52. The opposition division found that the skilled person would have had a reasonable expectation of success in view of closely related combination vaccines for dogs comprising the same attenuated viruses as mentioned in claim 1 and up to four other Leptospira serovars without antigenic interference.

53. None of the documents D25, D43, D44, D51, D79 provide any evidence of efficacy interference occurring in the development of canine Leptospira combination vaccines. Document D25 states that "[a] problem in developing combination vaccines involves efficacy interference, namely a failure of one or more antigens in a combination composition to maintain or achieve efficacy because of the presence of the other antigens in the composition" (page 2, lines 29 to 32). Document D43 (page 930, left hand column, penultimate paragraph) and document D44 (page 3186, left hand column, last paragraph) disclose the occurrence of efficacy interference in the development of multivalent human virus vaccines. In the passage pointed to by the appellant (page 106, section 3.1), document D51, a review article, states that immunogen interference is a problem in the generation of combination vaccines and from document D79 (paragraph bridging pages 59 and 60; page 60, left hand column, first full paragraph) it can be taken that it was common general knowledge that multivalent vaccines are tested to prove that there is no interference between the different antigens.

54. On the other hand before the effective date of the patent, commercially available canine Leptospira vaccines comprising a number of different Leptospira serovars and a number of canine viral antigens were available in the prior art. With the exception of L. bratislava, the Leptospira serovars and viral antigens in these commercially available vaccines are the same as in claim 1.

55. Thus, bivalent Leptospira vaccines comprising the serovars L. canicola and L. icterohaemorrhagiae were available as LEPTODOG**( ) (document D10, whole document), Caningen**( ) L (document D15, page 4) and Nobivac**( ) Lepto (document D20, page 123, last paragraph; document D42, page 167). Combination vaccines comprising the attenuated viruses CD, CAV-1 and/or CAV-2, CPI and CPV were available as Caningen**( ) DHPPi (document D15, page 4) and Nobivac**( ) DHPPi (document D20, page 123, last paragraph; document D42, page 164) while their combinations with bivalent Leptospira vaccines were available as Caningen**( ) DHPPi/L (document D15, page 4), Nobivac**( ) DHPPi + Lepto (document D20, page 123, last paragraph; document D42, page 164; document D47, paragraph bridging pages 165 and 166), Dohyvac 7L**( ) (document D47, paragraph bridging pages 165 and 166) and Vanguard**( ) 7 (document D47, paragraph bridging pages 165 and 166). As set out above (point 13.) document D25 discloses VANGUARD**( ) Plus 5/CV-L, a multivalent vaccine comprising inactivated whole cultures of L. canicola and L. icterohaemorrhagie, attenuated strains of CD, CAV-2, CPI, CPV viruses and inactivated CCV virus (document D25, page 53, lines 4 to 6). Finally, a tetravalent Leptospira vaccine comprising the serovars L. grippotyphosa and L. pomona in addition to L. canicola and L. icterohemorrhagiae was available as Duramune**( ) (document D12, whole document; document D16, page 3, third paragraph) and, in combination with the attenuated viruses CD, CAV-2, CPI CPV and CCV, as Duramune**( ) 10 (document D19, Example 4).

56. In the case at hand, evidence that the existence of effective, multivalent, canine Leptospira bacterin vaccines which protect dogs against leptospirosis belonged to the common general knowledge of the skilled person before the effective date of the patent in suit can be inferred from the sheer number of disclosures to that effect in the prior art (see also CLBA, I.C.2.8.1 and I.C.2.8.3).

57. The common general knowledge proven by documents automatically forms part of the "mental furniture of the skilled person" (T 939/92, OJ EPO 1996, 309, Reasons 2.3). A pointer to a particular document disclosing a certain fact is therefore not required if said fact forms part of the common general knowledge.

58. It was common ground that interference had to be tested with respect to all components in a commercial combination vaccine and that this was part of the common general knowledge of the skilled person. The disclosure of a commercially available combination vaccine therefore inherently discloses to the skilled person that there is no efficacy interference between the individual components. Thus, combinations of the canine viral antigens of claim 1 with Leptospira serovars other than L. bratislava were commonly known in the art and it was also known that no immunological interference had been observed for these combinations.

59. Document D64, a textbook, and therefore indicative of the common general knowledge, provides further evidence that efficacy interference was not a cause for concern of the skilled person. Thus, document D64 teaches that "[I]t has been found that a composite vaccine containing several serovars is useful and that the antigenic competition is quite minimal. Leptospiral vaccine can be given together with other vaccines, especially viral, without decreasing the specific antileptospiral immunity" (page 261, first full paragraph). That these findings also apply to canine Leptospira vaccines can be inferred from page 254 of document D64.

60. Contrary to the appellant's view, the fact that document D64 dates from 1994 does not diminish its relevance in the absence of any subsequent evidence that efficacy interference is a problem in the field of multivalent, canine, Leptospira vaccines. Indeed, document D64's teaching has been confirmed by the various multivalent canine Leptospira combination vaccines that have been developed in the art since its publication (see point 55. above).

61. Moreover it can be inferred from e.g. document D1 (example 4), document D10 (whole document), document D13 (page 371, right hand column, lines 4 to 6), document D15 (page 1, summary), document D20 (page 121, last paragraph), document D25 (page 53, lines 12 to 15), document D28 (page 157, middle column, last paragraph), document D42 (page 167, first paragraph), document D47 (page 169, left hand column, third full paragraph) that multivalent canine Leptospira bacterin vaccines were used, provided serovar-specific immunity against leptospirosis and reduced or eliminated clinical signs of disease. That this belonged to the common general knowledge is confirmed by document D62 (see page 307 left hand column, second full paragraph) and document D14 (Tables 1 and 2; page 7, lines 2 to 27), both of which are review articles and therefore indicative of the common general knowledge in the field of canine Leptospira vaccines.

62. While the appellant did not dispute that combination vaccines for dogs against Leptospira serovars other than L. bratislava were effective it submitted that since those vaccines were on the market, they had been tested beforehand as to their efficacy and thus as to whether there was a problem with efficacy interference and that the skilled person did not know whether a combination vaccine could protect against infection with L. bratislava.

63. However, the skilled person does not need to know in advance whether a combination vaccine will protect against L. bratislava infection to have a reasonable expectation that it would do so (see point 36. above).

64. The appellant has not pointed to any evidence that L. bratislava would behave differently from the other Leptospira serovars already included in commercially available vaccines and, in the view of the board, the skilled person would have been reassured by the lack of reports of failure for any of the known canine Leptospira combination vaccines.

65. The board considers that the skilled person would have balanced any concerns they may have had about efficacy interference in general against the evidence that there was no antigenic competition of Leptospira serovars from other Leptospira serovars or from viral antigens in commercially-available, effective, multivalent, canine Leptospira vaccines. This would have led the skilled person to expect that an inactivated cell preparation of any other Leptospira serovar would also be successful in providing protection against infection by that serovar when administered to dogs together with viral canine antigens and other leptospira serovars.

66. The skilled person, starting from the disclosure in document D25 and seeking to provide an effective vaccine for use in protecting dogs against infection with L. bratislava, would therefore reasonably have expected, on the basis of their common general knowledge, that the combination vaccine comprising L. bratislava disclosed in document D25 would provide effective protection in dogs against infection with

L. bratislava.

67. The board is not persuaded by any of the appellant's further lines of argument to the effect that the opposition division failed to acknowledge that several factors would have deprived the skilled person from a reasonable expectation of success, as set out in the following.

The generation of vaccines was generally unpredictable

68. The appellant argued that documents D43, D44, D14 and D25 provided evidence that the generation of vaccines was generally unpredictable and hence there was no reasonable expectation that vaccinating dogs with an

L. bratislava bacterin would successfully induce protection against L. bratislava infection.

69. Documents D43 and D44 relate to human anti-viral vaccines and are thus unsuitable to show that there was a belief in the art that the generation of vaccines was generally unpredictable or that there was unpredictability in the field of multivalent canine Leptospira vaccines.

70. Contrary to the appellant's assertion, document D14 (page 7, lines 3 to 10) does not show that there was a concern regarding multivalent canine Leptospira vaccines' efficacy. The reason the dogs failed to develop immunity was not because the bivalent L. canicola and L. icterohaemorrhagiae vaccine did not protect against these serovars, but because the vaccine does not protect against other prevalent serovars in the field. It belonged however to the common general knowledge of the skilled person before the effective date of the patent that protection against Leptospira infection was serovar specific, i.e. that a vaccine against one serovar did not protect against another serovar (document D14, page 7, lines 5 to 6; document D62, page 306, last sentence). Document D14 therefore does not diminish the skilled person's expectation that a L. bratislava bacterin would protect against L. bratislava infection in dogs.

71. Document D25 discloses that a multivalent Leptospira vaccine does protect dogs against infection by the serovars comprised in the vaccine (document D25, page 53, lines 12 to 15) and therefore does not support the appellant's case either.

72. In the board's opinion, the skilled person was aware of prior art vaccines which were more closely related to the claimed subject-matter than the vaccines disclosed in documents D43 and D44, and which comprised bacterins of Leptospira serovars, and had been successfully used to protect dogs against infection with the Leptospira serovars they comprised (see points 55. to 61. above). The skilled person would therefore not have perceived any particular unpredictability in the development of multivalent Leptospira vaccines for dogs, given the success in this field in the prior art.

73. Document D56, a chapter in a textbook and hence indicative of the common general knowledge in the art as to how leptospiral vaccines were produced, confirms that the expectation in the art was that the addition of another serovar would increase the breadth of protection (page 175, second paragraph).

74. Finally, the board considers that it can be inferred from document D3 (page 485, right hand column, second paragraph) and document D28 (page 157, middle column, second paragraph) both of which suggest the addition of the serovar bratislava to the already used leptospiral bacterins for dogs before the effective date of the opposed patent, that the skilled person also expected a bacterin comprising a cell preparation of L. bratislava to provide protection.

L. bratislava was not perceived as an emerging source for leptospirosis in dogs

75. As a further line of argument the appellant submitted that there was insufficient evidence that L. bratislava was a causative agent of leptospirosis in dogs. Therefore, as submitted by the appellant, there was no motivation to provide a vaccine against infection with L. bratislava and no reasonable expectation of success[deleted: ]that such a vaccine would protect against the disease.

76. In particular, the appellant submitted at the oral proceedings before the board that, although document D28 stated (at page 157, middle column, first paragraph) that in cases of multiple serovar titres, the higher titre was considered to be the infecting serovar, it nowhere stated that this also identified the serovar causing disease. However, this was the information that the skilled person would need before considering the production of a vaccine.

77. Firstly, in agreement with the decision under appeal (page 9, first paragraph) and the respondents' submissions, the board holds that the skilled person's motivation to include L. bratislava in a combination vaccine is irrelevant because the closest prior art already discloses a vaccine that comprises

L. bratislava.

78. Secondly, the board observes that document D28 states that "[t]he most common infecting serovars found were bratislava and grippothyphosa, confirming recent observations that demonstrate a significant change in the epidemiology of canine leptospirosis" (abstract). This suggests that the authors considered bratislava and grippothyphosa to be indeed causative of canine leptospirosis, i.e. the disease.

79. Document D28 furthermore concludes with the statement that "[v]accination is the method of choice in the prevention of leptospirosis, although protection induced by vaccination is primarily serovar-specific ... Commercially available vaccines containing canicola and icterohaemorrhagiae serovars are ineffective against the most prevalent infecting serovars identified in this study as well as in recent cases of acute leptospirosis diagnosed in Italy ... Several authors have suggested that antigens from serovars other than canicola and icterohaemorrhagiae should be included in the bacterins for dogs ... The reliability of a leptospiral vaccine containing five different serovars has been experimentally proven in dogs [..]." (page 157, middle column, last paragraph).

80. Document D28 therefore already suggested the addition of L. bratislava and L. grippothyphosa to the existing dog vaccines and also indicated that vaccination was the choice in prevention of leptospirosis (page 157, middle column lines 11 to 12) thus providing evidence that the skilled person thought L. bratislava was causative for the disease and that vaccination with bacterin comprising a cell preparation of L. bratislava was expected to protect against disease.

81. Thirdly, the board notes that it can be inferred from document D41, a chapter in a textbook, that it was accepted and part of the common general knowledge of the skilled person before the effective date of the patent that Leptospira serovar bratislava was a common cause for leptospirosis in dogs (page 188, lines 35 to 38; page 189, lines 5 to 6; Table 2). Therefore, the appellant's argument that serological tests, and in particular the MAT assay (see document D36), could not be used to interpret the identity of the infecting serovar has little weight. The fact that document D41 does not provide data to support its statements is irrelevant, as it is common for textbooks to rely on the data provided in the primary literature.

82. Document D45, relied on by the appellant as reflecting the common general knowledge of the person skilled in the art before the effective date of the patent, merely shows that L. bratislava was not considered to be a significant pathogen in dogs in the United States to justify the inclusion of L. bratislava in canine Leptospira-containing bacterins in the United States.

83. However, that not all Leptospira serovars were prevalent in a particular species in a particular region of the world belonged also to the common general knowledge of the skilled person before the effective date of the patent (document D41, page 188, line 33 to page 189, line 6). Indeed, the appellant concurred that the picture at the effective date of the patent was mixed with regard to the predominant serovars in dogs and that prevalence seemed to be strongly depended on the geographic area.

Challenge Models

84. According to the appellant, a further obstacle which the skilled person would have had to overcome was the fact that, at the effective date, there was no challenge model for L. bratislava, the development of such a challenge model being no easy task as evidenced by document D46.

85. In agreement with the respondents, the board considers that whether an adequate challenge model existed before the effective date of the patent, and the ease with which one could have been established, is not relevant to the question of whether there was a reasonable expectation of the skilled person that the vaccine disclosed in document D25 would provide effective protection in dogs against infection by L. bratislava. Indeed, the reasonable expectation is in the mind of the skilled person, and is independent of the actual existence of a challenge model to test the vaccine. Thus, testing a vaccine in a challenge model to see whether it actually works is different from having a reasonable expectation that it would work. Therefore, a challenge model was not necessary for the skilled person to have a reasonable expectation of success when trying to develop a vaccine that protects against infection.

86. Document D46 is in any event post-published and therefore irrelevant, since information becoming available after the effective date could not have influenced the skilled person's expectations of success before the effective date.

87. In conclusion, none of the appellant's arguments to the effect that several factors would have deprived the skilled person from a reasonable expectation of success are found persuasive.

88. In these circumstances, there is no need to consider whether the skilled person was in a try and see situation or not.

89. In view of the above considerations, the board sees no reason to set aside the decision under appeal on this point.

90. The subject-matter of claim 1 of the main request contravenes Article 56 EPC.

Auxiliary requests 1, 2 and 3 - claim 1

Inventive step - Article 56 EPC

91. The appellant did not argue that any of the amendments made in claim 1 of auxiliary requests 1, 2 and 3 contributed to an inventive step of the claimed subject-matter. Instead, it relied on its arguments for claim 1 of the main request. These arguments were not considered convincing by the board (see points 10. to 90. above).

92. Claim 1 of auxiliary requests 1, 2 and 3 therefore do not meet the requirements of Article 56 EPC for the same reasons as set out above, mutatis mutandis, for claim 1 of the main request.

Auxiliary request 4

Admittance and consideration (Article 13(2) RPBA)

93. Initially, the appellant filed the set of claims of auxiliary request 4 to address a new added subject-matter objection raised by respondent II against the main request and conditionally requested its admission into the proceedings should the board admit

respondent II's new objection into the proceedings (section X. above).

94. During the oral proceedings before the board, after the board had announced its opinion that the main request contravened Article 56 EPC and that this opinion appeared to apply to auxiliary requests 1 to 3, the appellant stated that auxiliary request 4 was now presented unconditionally, in response to a new line of argument raised during the oral proceedings.

95. Admittance of auxiliary request 4 is therefore governed by Article 13(2) RPBA, which provides that any amendment to a party's case after notification of a communication under Article 15(1) RPBA, shall, in principle, not be taken into account unless there are exceptional circumstances, which have been justified with cogent reasons by the party concerned.

96. The appellant submitted that auxiliary request 4 was presented in a bona fide attempt to overcome a potential issue on inventive step and should be admitted into the proceedings under Article 13(2) RPBA. The potential issue was that protection against infection by L. bratislava was not sufficient to provide an effective vaccine, and that the disease caused by L. bratislava had to be prevented.

97. However, neither the respondents nor the board had argued that protection against infection by L. bratislava would not be sufficient to provide an effective vaccine and that the disease caused by L. bratislava had to be prevented. Furthermore, as can be seen from points 32. to 87. above, the board's decision on inventive step is not based on the notion that protection against infection by L. bratislava would not be sufficient, but that the disease caused by

L. bratislava must be prevented in order to recognise inventive step.

98. Instead, it was the appellant who argued during oral proceedings before the board (see point 76. above) that evidence of infection by L. bratislava, as disclosed in document D28, in the absence of evidence that

L. bratislava was causative for the disease was not sufficient to motivate the skilled person to develop a vaccine against L. bratislava.

99. The board therefore shares the respondents' view that the scenario which, in the appellant's view, served as a justification for the late submission of this claim request had been constructed by the appellant, in view of its own interpretation of document D28 during the oral proceedings.

100. Moreover, besides the absence of exceptional circumstances justified with cogent reasons, the board also shared the view of the respondents that it made no difference for the assessment of inventive step, whether the claim is directed to protection against infection by L. bratislava or protection against disease caused by L. bratislava. As noted above, L. bratislava was emerging as a causative agent of canine leptospirosis before the effective date of the patent. The skilled person would have known that if a vaccine prevents infection, it will also prevent disease. Therefore, the same arguments as for the main request applied and the issue of lack of inventive step would not have been overcome by auxiliary request 4.

101. Thus, there were no exceptional circumstances, justified with cogent reasons for the admittance of auxiliary request 4 and the board decided not to admit it under Article 13(2) RPBA.

Conclusion

102. The main request and auxiliary requests 1, 2 and 3 are not allowable and auxiliary request 4 was not admitted into the appeal proceedings. As the appellant's conditions relating to the presentation of auxiliary requests 2a, 3a and 5 to 9 have not materialised, they needed not to be dealt with. Since the present decision could be taken without taking into account the documents the admittance of which was contested and which according to the respondents should be admitted, no decision was required on the admittance of these documents.

103. In the absence of an allowable claim request in the proceedings before the board, the decision under appeal cannot be set aside and the appeal must be dismissed.

Order

For these reasons it is decided that:

The appeal is dismissed.