T 0636/21 (Keratinaceous material/TESSENDERLO) of 27.6.2023

Summary of Facts and Submissions

I. Opponents 1 and 2 (appellants 1 and 2) lodged appeals against the opposition division's interlocutory decision holding the main request allowable.

II. With their notices of opposition, opponents 1 and 2 had requested that the patent be revoked on the grounds for opposition under Article 100(a) EPC (lack of novelty and lack of inventive step), Article 100(b) EPC and Article 100(c) EPC.

III. The opposition division decided that the subject-matter of claim 1 of the main request met the requirements of Articles 83, 84 and 123(2) EPC, was novel over D1 and D23, inter alia, and involved an inventive step.

IV. Claims 1 and 10 of the main request read as follows:

"1. Method for the production of highly digestible hydrolysed keratinaceous material comprising the steps of (iii) subjecting partly hydrolysed, partly insoluble keratinaceous material obtained from thermal and pressure hydrolysation with 20 wt% or more of the keratinaceous material having a molecular weight of about 5000 dalton or higher, to a chemical hydrolysis step, with a strong mineral acid to obtain a highly digestible hydrolysed material, and (iv) purifying the highly digestible material, wherein the highly digestible keratinaceous material has 95% by weight or more of material of a molecular weight of 5000 dalton or lower and an in vitro digestibility of 98% or more in both the ileal and pepsin digestibility test, wherein the ileal digestibility is measured according to S. Boisen, Livestock Science (2007) 309:182-185 and the pepsin digestibility is measured according to ISO 6655 (August 1997)."

"10. Highly digestible hydrolysed keratinaceous material, obtainable with the method of any one of claims 1-9, wherein the highly digestible hydrolysed keratinaceous material has an amino acid composition reflecting the amino acid composition of the raw material, wherein the amount of decarboxylated amino acids is less than 1000 ppm, preferably less than about 500 ppm, and more preferably less than about 300 ppm and wherein the highly digestible keratinaceous material has 95% by weight or more of material of a molecular weight of 5000 dalton or lower and an in vitro digestibility of 98% or more in both the ileal and pepsin digestibility test, wherein the ileal digestibility is measured according to S. Boisen, Livestock Science (2007) 309:182-185 and the pepsin digestibility is measured according to ISO 6655 (August 1997)."

Claims 2 to 9 of the main request are dependent method claims, claims 11 to 13 are dependent product claims, and claim 14 is a use claim.

Auxiliary request 1, orally submitted during the oral proceedings before the board (see the minutes of the oral proceedings), consists of nine claims, wherein claims 1 to 9 of auxiliary request 1 are identical to claims 1 to 9 of the main request.

V. The following documents were cited in the present case:

D1: US 3,006,809

D21: US 5,049,397

D22: US 4,172,073

D23: R.J. Steiner et al., "Effect of sodium hydroxide

and phosphoric acid treatment on pepsin and in

vitro digestibilities of steam hydrolyzed feather

meal", Proceedings, Western Section, American

Society of Animal Science, vol. 32, pages 56 to

59, 1981

D25: FR 2 448 297

D33: Experimental report filed by appellant 2

D34: Experimental report filed by the patent proprietor

(respondent)

VI. The parties' relevant arguments, submitted in writing and during the oral proceedings, are reflected in the reasons for the decision below.

VII. Requests

The appellants requested that the decision be set aside and that the patent be revoked.

The respondent requested that the appeal be dismissed (main request) or, as an auxiliary measure, that the patent be maintained on the basis of auxiliary request 1 submitted during the oral proceedings before the board.

Reasons for the Decision

MAIN REQUEST

1. Sufficiency

1.1 The appellants argued that the invention could not be carried out. As evidence to raise serious doubts that the product according to claim 10 could be obtained, they relied mainly on the experimental report D33. In the appellants' view, the method in claim 1 could not be carried out either, since some of the reworked examples in D33 failed to achieve the required digestibilities and, at the same time, the feature "wherein the highly digestible keratinaceous material has 95% by weight or more of material of a molecular weight of 5000 dalton or lower".

D33 is an experimental report in which examples 5, 7 and 10 of the patent have been reworked.

1.2 The respondent counter-argued that the invention could be carried out. In its view, the experimental counter-report D34 was suitable for demonstrating that the product according to claim 10 could be produced. Method claim 1 could be carried out as well.

D34 is an experimental report reworking example 10 of the patent on the same scale and on a scale which is 50% of the scale mentioned in example 10.

1.3 Claim 10

1.3.1 Claim 10 relates to a highly digestible hydrolysed keratinaceous material having the following features:

(i) wherein the highly digestible hydrolysed keratinaceous material has an amino acid composition reflecting the amino acid composition of the raw material,

(ii) wherein the amount of decarboxylated amino acids is less than about 1000 ppm, preferably less than about 500 ppm, and more preferably less than about 300 ppm,

(iii) wherein the highly digestible keratinaceous material has 95% by weight or more of material of a molecular weight of 5000 dalton or lower,

(iv) an in vitro digestibility of 98% or more in both the ileal and pepsin digestibility test.

1.3.2 A prerequisite for successfully contesting that the invention can be carried out and for demonstrating that the claimed product cannot be obtained without undue burden is that the appellants raise serious doubts substantiated by verifiable facts that the invention can be carried out.

1.3.3 Appellant 2 reworked examples 5, 7 and 10 of the patent in D33, from which it can be derived that the combination of features (i) to (iv) was not achieved, although the experiments were carried out closely in line with the details given in the respective examples of the patent (see in particular Tables C and E of D33).

Reworked examples 7 and 10 of D33 were carried out on a scale of 100 g starting material, and not 100 kg, as mentioned in examples 7 and 10 of the patent. Reworked example 5 of D33 was carried out on a scale of 100 g, which is exactly the amount mentioned in example 5 of the patent.

In reworked example 5 of D33, features (iii) and (iv) are not achieved.

In reworked example 7 N°1 of D33, feature (ii) is not achieved.

In reworked examples 10 N°1, 10 N°2, 10D and 10C of D33, features (ii) and (iv) are not achieved.

1.3.4 The board considers these experiments in D33 to be in line with the teaching provided in the patent, and not as being designed to fail.

The respondent argued that examples 7 and 10 required a larger scale of 100 kg of starting material, and not only 100 g, as used in examples 7 and 10 of D33.

The board is not convinced by this argument.

1.3.5 Example 5 of the patent, which is supposedly an example in line with the patent, uses 100 g of starting material, i.e. exactly the same amount as used in reworked example 5 of D33. The same acid mentioned in example 5 of the patent was used in reworked example 5 of D33 and the process conditions were in line with the conditions taught in the patent as well. Therefore, reworked example 5 of D33 is a bona fide attempt to try to produce the claimed product.

1.3.6 There is no teaching in the patent that a pilot scale of about 100 kg of starting material might be crucial for achieving the desired results. While scaling up processes may be problematic for various reasons, in the present case there is no reason why scaling down could be problematic. Example 5 of the patent uses an amount of 100 g as the starting material, which supports the fact that the claimed process is not limited to a certain scale.

Therefore, the board considers not only the reworked example 5 of D33 but also the reworked examples 7 and 10 of D33 bona fide attempts to try to produce the claimed product.

1.3.7 In this context, it is further noted that none of the examples in the patent mentions that the combination of features (i) to (iv), as now called for in claim 10, is achieved at the same time.

1.3.8 The respondent's criticism that when reworking example 5 only a "single feather" ("une plume") is used is not convincing. It is clear that what is meant in reworked example 5 of D33 is that one kind of feather is used, and not a single piece of keratinaceous material in the form of a feather, which of course cannot correspond to 100 g feather meal as mentioned in reworked example 5 of D33.

1.3.9 The board concludes that the failing reworked examples 5, 7 N°1, 10 N°1, 10 N°2, 10C and 10D (see point 1.3.3 above) raise serious doubts that the claimed product having the combination of features (i) to (iv) can be obtained without undue burden.

1.3.10 The respondent argued that its experimental counter-report D34 demonstrated that the claimed product can be successfully produced when reworking example 10 of the patent on a scale of 100 kg or 50 kg.

However, the crucial question is whether a skilled person is guided by the patent and their common general knowledge of how to render the failing reworked experiments of D33 successful. In the board's view, the patent does not contain sufficient guidance for a skilled person on how to render the failing experiments successful. While it might be expected that features (iii) and (iv) may be achieved by increasing the processing time and the acid concentration, it is doubtful whether features (i) and (ii) can be achieved when increasing the processing time, acid concentration and temperature. Therefore, achieving features (i) and (ii) conflicts with achieving features (iii) and (iv) at the same time, so in the board's view it is an undue burden for a skilled person to achieve features (i) and (ii) and, at the same time, features (iii) and (iv).

1.3.11 The respondent also argued that the starting material used in D33 was not suitable for achieving the required combination of features in claim 10; however, first, there is no particular limitation on the starting material in the patent. Second, the respondent did not explain which exact measures are necessary to select a proper starting material and which starting material might be suitable for achieving the specific combination of features required in claim 10. This information is not derivable from paragraph [0124] of the patent, either, which was referred to by the respondent and from which it may be derived that a starting feather meal of good quality should be used. There is no reason to assume that a feather meal or feathers of inappropriate quality were used in D33.

Therefore, as far as the product in claim 10 is concerned, the invention cannot be carried out (Article 83 EPC).

1.4 Claim 1

1.4.1 When assessing the question of sufficiency of the main method claim 1, it is to be noted that features (i) and (ii) (present in product claim 10) are not part of claim 1, but only features (iii) and (iv). Therefore, the issue of the conflicting features present in claim 10 does not exist in claim 1.

1.4.2 In this context, the appellants argued that it could be seen from the experimental report D33 (reworking examples 5, 7 and 10 of the patent) that any amount of acid for any time did not make it possible to obtain a highly digestible keratinaceous material having 95% by weight or more of material of a molecular weight of 5000 dalton or lower and an in vitro digestibility of 98% or more in both the ileal and pepsin digestibility test.

1.4.3 While it is correct that, in reworked example 5 of D33, the digestibility requirement and the molecular weight requirement could not be achieved simultaneously, it is noted that reworked examples 7 N°1, 7 N°2 and 10 N°1 and 10 N°2 achieve both requirements and examples 10D and 10C only fail to achieve the required pepsin digestibility. The board is of the opinion that a skilled person is aware that the pepsin digestibility of a hydrolysed keratinaceous material can be increased by increasing the processing time and/or the acid concentration (see for instance the teaching in D23). For a similar reason, a skilled person would expect that increasing the processing time and/or the acid concentration in example 5 of D33 would lead to a product in line with the requirements of the final product produced according to the method in claim 1.

1.4.4 The appellants further argued that claim 1 failed to mention the amount of acid, processing time and temperature, so a skilled person would not be given any guidance on how to obtain the final hydrolysed keratinaceous material in claim 1. This line of argument is not convincing, since the specification provides the required details for these conditions. For the assessment of sufficiency, the patent as a whole is to be considered, not just the claims.

Therefore, as far as the method in claim 1 is concerned, the invention can be carried out (Article 83 EPC). The same applies to the dependent method claims.

2. For the reasons given under point 1.3 above, the main request is not allowable.

AUXILIARY REQUEST 1

3. Auxiliary request 1 consists of nine claims, wherein claims 1 to 9 of auxiliary request 1 are identical to method claims 1 to 9 of the main request. Therefore, for the reasons given under point 1.4 above, the method in claims 1 to 9 meets the requirement of Article 83 EPC.

4. Article 123(2) EPC

4.1 The appellants argued that the subject-matter of claim 1 violated the requirement of Article 123(2) EPC.

4.2 For the following reasons, the board is not convinced.

4.2.1 Claim 1 is, inter alia, based on claims 4, 6 and 7 of the application as filed.

4.2.2 The objection against the term "thermal" raised by appellant 1 is unconvincing, since said term is used in independent claim 4 of the application as filed. Independent claim 1 of the application as filed, which does not contain the term "thermal", is not a basis for claim 1.

4.2.3 The features concerning the definition of the highly digestible material, and in particular the combination of the fraction having a specific molecular weight and the definition of the digestibility, are disclosed in paragraph [0008] (see also claim 6), paragraph [0088] and claim 14 of the application as filed.

4.2.4 The feature directed to the in vitro digestibility in both the ileal and pepsin digestibility test is disclosed in paragraph [0088] and claim 14 of the application as filed. The combination of the latter two digestibility features is disclosed in the application as filed, when taking into account the content of the whole application. Omitting the reference to "dry" material as used in paragraph [0088] does not lead to a violation of Article 123(2) EPC. The board also agrees with the opposition division's conclusion that a skilled person understands that drying or the mode of drying would not change the digestibility (see impugned decision, page 5, first paragraph).

4.2.5 The application as filed provides a basis for the feature "20 wt% or more of the kerationaceous material has a molecular weight of about 5000 dalton or higher", as introduced into claim 1 (see paragraph [0064] of the application as filed), which defines the partly hydrolysed, partly insoluble keratinaceous material obtained from thermal and pressure hydrolysation, and not the raw material before thermal and pressure hydrolysation.

In the board's view, there is no inextricable link between the features disclosed in the first sentence of paragraph [0064] and those disclosed in the second sentence in paragraph [0064]. In particular, weight percentages of material having a certain molecular weight expressed in dalton are disclosed throughout the application as filed without referring to the features relating to the solvent system referred to in the first sentence of paragraph [0064].

4.2.6 The methods for measuring the pepsin digestibility and ileal digestibility, as introduced into claim 1, are disclosed in paragraphs [0098] and [0099].

In view of the above, the subject-matter of claim 1 fulfils the requirement of Article 123(2) EPC.

5. Article 123(3) EPC

The appellants raised a criticism that example 6 of the patent, which uses a non-hydrolysed feather as a starting material and not a partly hydrolysed keratinaceous material as required in claim 1, is not specified as not being in accordance with the invention. In their view these circumstances raise doubts as to whether the claimed process requires a partly hydrolysed keratinaceous material as the material to be subjected to the chemical hydrolysis step as mentioned in claim 1, or possibly a non-hydrolysed feather as used in example 6 of the patent.

The board concludes that this alleged lack of adaptation of the description does not lead to a violation of Article 123(3) EPC. It is evident from the method in claim 1 that in step (iii) a partly hydrolysed, partly soluble keratinaceous material is to be used, not a non-hydrolysed feather.

6. Article 84 EPC

6.1 The appellants raised an objection under Article 84 EPC and argued that it was not clear which feature the expression "with 20 wt% or more of the keratinaceous material having a molecular weight of about 5000 dalton or higher" referred to. Moreover, the features newly introduced into claim 1 related to a result to be achieved, leading to a clarity problem, since the claimed subject-matter does not contain all the essential features. In addition, the term "strong mineral acid" in claim 1 was considered as being unclear.

6.2 For the following reasons, there is no lack of clarity (Article 84 EPC).

It is clear from the wording of claim 1 that the expression "with 20 wt% or more of the keratinaceous material having a molecular weight of about 5000 dalton or higher" refers to the partly hydrolysed, partly insoluble keratinaceous material, and not to the previous raw material before thermal and pressure hydrolysation. A skilled person reads claim 1 in such a manner.

The parametric definition of the in vitro digestibility in claim 1 does not lead to a lack of clarity either. Moreover, the claims as granted already contained a corresponding, even less detailed, definition (see in particular claim 14), and therefore the objection of allegedly missing essential features cannot be examined pursuant to G 3/14.

The term "strong mineral acid" is already present in claim 7 of the patent as granted, so it is not open to an examination of clarity (see G 3/14).

Therefore, the clarity objections raised by the appellants do not support a lack of clarity within the meaning of Article 84 EPC.

7. Novelty

7.1 The appellants raised novelty objections against the subject-matter of claim 1 in view of D1 and D23.

7.2 For the following reasons, the board does not agree.

Claim 1 requires that the highly digestible keratinaceous material have an in vitro digestibility of 98% or more in both the ileal and pepsin digestibility test. The board is unable to see that either of documents D1 or D23 unambiguously discloses such a high degree of in vitro digestibility in both digestibility tests. Even when considering the experimental report D33, the required in vitro digestibilities are not achieved.

In this context, the board does not share the appellants' view that the feature "in vitro digestibility of 98% or more" is to be interpreted more broadly when interpreting the digestibility values with a measuring uncertainty of ± 4%. There is no evidence on file that the uncertainty is indeed so significant. As can be derived from D23, for instance, the pepsin digestibility values given in Table 1 of D23 are given to one decimal place, so they are clearly distinguishable from each other and accurate to one decimal place. There is not sufficient evidence that the uncertainty when measuring the digestibilities is indeed as high as alleged by the appellants. In this context, it is noted that, as part of the assessment of sufficiency of disclosure, the digestibility values were discussed in detail and it was concluded that it was an undue burden to obtain the conflicting features of claim 10 of the main request at the same time. In this discussion, the digestibility values were given a precise meaning. The digestibility values now cannot be given any other meaning in the assessment of novelty.

In view of the above, it cannot be concluded that the high digestibilities required in claim 1 are indeed achieved in D1 and D23.

Therefore, the subject-matter of claim 1 is considered novel over D1 and D23. The same applies to the dependent claims.

8. Inventive step

8.1 Appellant 1 argued that the method in claim 1 did not involve an inventive step in view of D1 or D22 as the closest prior art in combination with D21. Appellant 2 argued that the method in claim 1 did not involve an inventive step in view of D23 as the closest prior art, whereas D25 did not constitute the closest prior art. In writing, appellant 1 also submitted arguments starting from D25 as the closest prior art, but at the oral proceedings relied on D22 as a starting point for inventive step.

8.2 For the following reasons, the inventive step objections raised by the appellants are not convincing.

8.3 D1 relates to a different technical field than the opposed patent, i.e. to methods of attracting and exterminating insects such as cockroaches. D1 does not mention that achieving a high digestibility and a high nutritional value is desired, but instead a very different purpose is intended in D1, i.e. exterminating cockroaches. Therefore, D1 is not an appropriate starting point for assessing inventive step.

8.4 D22 and D23 are suitable starting points for assessing inventive step.

8.4.1 D22 relates to a process for preparing a water-soluble keratinaceous protein using saturated steam and water and one of the objects is to provide a keratinaceous protein that is substantially wholly digestible by pepsin. Another object of D22 is to provide a substantially odourless keratinaceous protein which is suitable for use in food for animals or humans. There is no doubt that D22 is an appropriate starting point for assessing inventive step in the present case, given the similarities in technical field and purpose of the invention.

8.4.2 D23 is directed to studying the effect of, for instance, phosphoric acid treatment on pepsin and in vitro digestibilities of steam hydrolysed feather meal.

The objectives of this study were to determine if, for instance, acid treatment, in combination with steam processing, decreases the processing time required to produce a digestible feather meal product, and if chemical treatment influences pepsin digestibility of crude protein, for instance. Therefore, D23 equally qualifies as an appropriate starting point for assessing inventive step.

8.5 In view of the parties' submissions, the board is unable to see that D25 is a more promising starting point for assessing inventive step. Considering that neither appellant wished to rely on D25 as the closest prior art and that appellant 1 submitted arguments starting from D25 just in case the board followed the respondent's position to take D25 as the closest prior art, there is no need to assess inventive step starting from this document.

8.6 Under these circumstances, inventive step is dealt with in the following only in view of D22 and D23 as the closest prior art.

8.7 D22 as closest prior art

D22 does not disclose the step of chemical hydrolysis using a strong mineral acid as required in claim 1. To the contrary, as can be derived from the method in claim 1, D22 even explicitly excludes acids from being used.

Even if no effect were acknowledged over D22 and the objective technical problem were formulated as that of providing an alternative method for producing a highly digestible hydrolysed keratinaceous material, the claimed method involves an inventive step as outlined below.

With respect to the question of obviousness, the board notes that D22 explicitly teaches that no acids, bases or other chemical additives are used in the method for preparing the water-soluble keratinaceous protein (see column 2, lines 26 to 29, and claim 1). The board concludes from said passages that D22 provides teaching leading away from contemplating an acid hydrolysis step as required in claim 1.

In this context, appellant 1 argued that a skilled person wishing to increase the digestibility of the keratinaceous material would have been motivated by D21 to contemplate an additional acid hydrolysis step; however, as outlined above, this would go against the teaching of D22, which explicitly excludes the addition of acids (see claim 1 of D22). Therefore, the claimed method is considered a non-obvious alternative over D22 as the closest prior art.

In view of the above, the subject-matter of claim 1 involves an inventive step in view of D22 as the closest prior art. The same applies to the dependent claims.

8.8 D23 as the closest prior art

As can be derived from the section "Materials and Methods" in D23, feathers, and not a partly hydrolysed, partly insoluble keratinaceous material, are subjected to chemical hydrolysis with phosphoric acid as the strong acid (see section "Materials and Methods", right-hand column on page 1 of D23). As a second step in the method in D23, the treated samples were subjected to steam processing. Therefore, D23 does not disclose that a partly hydrolysed, partly insoluble keratinaceous material obtained from thermal and pressure hydrolysation is used in step (iii) as required in claim 1.

In addition, it cannot be unambiguously derived from D23 that it discloses the in vitro digestibility feature as required in claim 1. Although the pepsin digestibility in D23 is measured by applying a method using a higher pepsin concentration than the method specified in claim 1, the highest value achieved in D23 is only 94.6% (see Table 1, entry for 9.0% H3PO4 for 16 hours, in D23) which is below the 98% or more as required in claim 1. Under these circumstances, the board does not agree with appellant 2 that the digestibility requirement of claim 1 is implicitly fulfilled in D23 (see point 7. above).

In view of the above, the effect resulting from the distinguishing features is considered to be increased digestibility of the keratinaceous material, so the objective technical problem is considered that of providing a method for the production of a keratinaceous material having increased digestibility.

With respect to the question of obviousness, the board draws the following conclusion.

It is true that a skilled person wishing to increase the digestibility would simply increase the amount of acid and the processing time as explicitly taught in D23 (see section "Results and Discussion" on page 57 of D23).

While D23 teaches that an increase in acid concentration and processing time leads to higher digestibility, a skilled person is not motivated to change the order of the process steps taught in D23. While D23 requires that feathers are subjected to an acid treatment, claim 1 requires that in step (iii) a partly hydrolysed, partly insoluble keratinaceous material obtained from thermal and pressure hydrolysation is subjected to a chemical treatment with a strong mineral acid. In the board's view, this is neither taught in D23 nor is this modification to the method obvious in view of the teaching of D23. In D23 the effect of phosphoric acid treatment on digestibility properties is studied and, as a first step, feathers are subjected to acid treatment and, as a second step, a steam processing step is carried out. D23 does not motivate a skilled person to change the order of these steps. In addition, it is not obvious from the teaching of D23 to replace the feathers as the raw material with a partly hydrolysed, partly insoluble keratinaceous material obtained from thermal and pressure hydrolysation, since this would go against the purpose of the study in D23.

In view of the above, the subject-matter of claim 1 involves an inventive step in view of D23. The same applies to the dependent claims.

9. Therefore, auxiliary request 1 is allowable.

Order

For these reasons it is decided that:

1. The decision under appeal is set aside.

2. The case is remitted to the opposition division with the order to maintain the patent on the basis of auxiliary request 1 as submitted during the oral proceedings before the board (consisting of claims 1 to 9 of the main request, i.e. the set of claims held allowable by the opposition division) and a description to be adapted to this request.