T 0420/19

10.03.2022


Appeals were filed by the patent proprietor (appellant I) and by the opponent (appellant II) against the opposition division's interlocutory decision that European patent No. 2 373 154, entitled "Barley and malt-derived beverages with low dimethyl sulfide level", amended according to auxiliary request 8, met the requirements of the EPC (Article 101(3)(a) EPC).
In the decision under appeal, the opposition division held that the subject-matter of claim 6 of the main request and of auxiliary requests 1, 3, 4, 6 and 7 was excepted from patentability pursuant to Article 53(b) EPC. The ground for opposition under Article 100(b) EPC was introduced into the opposition proceedings by the opposition division, which held that the subject-matter of claim 6 of auxiliary requests 2 and 5 did not meet the requirements of Article 83 EPC.
Claim 6 as granted (main request) reads:
"6. A barley plant, or part thereof, wherein the barley plant carries a mutation in the gene encoding methionine-S-methyltransferase (MMT) that causes a total loss of MMT function".
Claim 6 of auxiliary request 8 reads:
"6. A barley plant, or part thereof, wherein the barley plant carries a mutation in the gene encoding methionine-S-methyltransferase (MMT) that causes a total loss of MMT function wherein the mutation is a
G -> A mutation of base no. 3076 of SEQ ID NO:3,
with the proviso that the barley plant has not exclusively been obtained by means of an essentially biological method".
Appellant II submitted that the claimed barley plants fell under the exception to patentability defined in Article 53(b) EPC because they were the direct product of an essentially biological process. Appellant II was of the view that such plants had been excluded from patentability at least since the adoption of the EU Biotech Directive 98/44, which became an integral part of the EPC in 1999 via the adoption of Rules 26 to 29 EPC. They argued that the Enlarged Board of Appeal, in its Opinion G 3/19, should not have set 1 July 2017 (the date when Rule 28(2) EPC came into force) as the date when the new interpretation of Article 53(b) EPC, determined in the Opinion G 3/19, was to be applied.
The board notes that the EBA has, in Opinion G 3/19, already dealt with the considerations raised by Appellant II. The EBA further decided that "the new interpretation of Article 53(b) EPC given in this opinion has no retroactive effect on European patents containing such claims which were granted before 1 July 2017, when Rule 28(2) EPC entered into force, or on pending European patent applications seeking protection for such claims which were filed before that date".
Since the patent was granted before 1 July 2017, the subject-matter of claim 6 (and dependent claims 7 to 9 and 16) is not excepted from patentability in view of Article 53(b) EPC as interpreted by the decisions of the EBA G 2/12 and G 3/12.
With regard to the claim request considered allowable by the opposition division, appellant II submitted that the subject-matter of claim 6 (of auxiliary request 8 and of main request) lacked an inventive step in view of the disclosure in document D1 alone or in combination with common general knowledge.
D1 is the closest prior art and reports that the function of S-methyl-methionine (SMM) and its cycle was investigated by isolating and characterizing insertional knockout (null) mutants of MMT in Arabidopsis and maize (Zea mays), which both have single MMT genes, and the finding that SMM was dispensable, but that eliminating it caused an increase in the adenosine-methionine level and in the methylation ratio.
The difference between the claimed plant and those described in document D1 is the plant species, i.e. barley rather than maize or Arabidopsis. The technical effect of this difference is that MMT is knocked out in barley as opposed to maize or Arabidopsis. Due to the loss of MMT function, the claimed barley plants produce kernels which, when germinating, have lower SMM levels than their non-mutant equivalents. Malted barley kernels, when used in the production of beer, result in beer having a low level of dimethyl sulfide (DMS), e.g. below 20 ppb and a low level of SMM, e.g. less than 20 ppb. This beer has an improved taste profile due to lower DMS levels.
In view of the above differences and the effects thereof, the objective technical problem can be seen as provision of additional plants with an MMT null mutation.
Document D1 discloses that insertional MMT mutants of Arabidopsis and maize lacked the capacity to produce SMM from methionine (Met) and S-adenosyl-methionine (Ado-Met) and thus had no SMM cycle. The mutant plants nevertheless grew and reproduced normally, and the seeds of the Arabidopsis mutant had normal sulfur contents. Document D1 does not mention barley and discloses no connection between the effect of knocking out the MMT gene and any potential use in the production of beer with improved flavour. Moreover, there is no mention of DMS or of any link to the problem of undesirable flavour in beer, which might have provided an incentive to create MMT null mutant barley plants. Thus, the skilled person seeking to solve the problem formulated above and starting from document D1 would have had no incentive to choose barley as an alternative plant for making MMT null mutants.
The board concludes that the subject-matter of claim 6 was not obvious to the skilled person. Claim 6 and its dependent claims therefore meet the requirements of Article 56 EPC.
In the decision under appeal, in respect of claim 6 of auxiliary request 2 which differs from claim 6 of the claims as granted only in that it includes a proviso that the barley plant has not exclusively been obtained by means of an essentially biological method, the opposition division held that the requirements of Article 83 EPC were not met.
The opposition division considered that the only methods given in the patent to obtain the claimed mutants was mutagenesis and subsequent screening, thus relying on identification of a chance event and that in view of the number of plants that would have to be screened to arrive at the claimed invention, it was undue burden to identify further mutants.
The board considers that the mere fact that mutagenesis is a random process and that large numbers of mutant barley plants might have to be screened does not, in the present case, represent an undue burden the skilled person. In the present case, the invention is reproducible without undue burden because there is evidence that the chance event can be identified frequently enough to guarantee success.
In view of the above considerations, the board concludes that the invention of claim 6 and its dependent claims meets the requirements of Article 83 EPC.
The claims of the patent as granted and their subject-matter are considered to meet the requirements of the EPC.
The patent is maintained as granted.

https://www.epo.org/law-practice/case-law-appeals/recent/t190420eu1.html