6. The question arises, whether the Board's reliance on an objective problem that was never mentioned to the petitioner amounts to a fundamental violation of the right to be heard. In the Enlarged Board's view, this question cannot generally be answered in the affirmative. The application of the problem-solution approach can be viewed as a method of determining and reasoning whether a claimed invention fulfils the requirement of inventive step (Articles 52 and 56 EPC).
7. There is no obligation to apply the problem-solution approach. However, regardless of whether and how the problem-solution approach is used, the right to be heard means, at least, that the parties must be heard on the basis of the reasoning used in the decision. In the context of the problem-solution approach, there should normally have been a discussion on the relevant prior art, the differences between the prior art and the claimed invention, and the technical relevance of these differences. Within the framework of what has been addressed in the course of these discussions, the deciding organ should be free to apply the problem-solution approach as it sees fit, and even identify an objective problem that has not been explicitly spelled out as such during the proceedings. In any case, the objective problem eventually used in the reasoning has to be based on technical effects (or the lack of any) and the features of the invention causally linked to such effects, upon which the parties had an opportunity to comment.
8. In its letter of 22 January 2024 and during oral proceedings before the Enlarged Board, the petitioner basically agreed with this legal analysis. On the one hand, the petitioner accepted that, within the framework of what has been discussed with the parties, the deciding organ should be free to apply the problem-solution approach as it saw fit, and this could include the identification of an objective problem that had not been explicitly spelled out. On the other hand, the petitioner argued that the parties should be able to foresee the factual basis on which the deciding organ could base its problem-solution approach, and must not be surprised by the reasoning in the decision.
9. In this context, the Enlarged Board notes that, according to consistent case law, subjective surprise has no bearing on whether a party knew the issues and had an adequate opportunity to comment upon (see, for example, R 12/09 of 15 January 2010, Reasons 13; R 15/10, Reasons 11; R 5/16, Reasons 19). In addition, reasoning based on the submissions of another party cannot be surprising (R 4/08, Reasons 3.3). For the purposes of Article 113(1) EPC, it is sufficient if a reason corresponds to an argument forwarded by another party (R 1/13, Reasons 10). Whether a party can be considered to have been taken by surprise is assessed on an objective basis (R 4/14, Reasons 3).
Technical context
10. Claim 1 of the patent as granted (main request in appeal) reads (to simplify, one passage has been abbreviated):
"A pharmaceutical formulation in the form of an erosion matrix tablet comprising:
i) 10 % to 80 % by weight of [...] as an active substance;
ii) 1-50 % by weight of one or more rate-controlling agents; and
an enteric coating, wherein said enteric coating is applied at a level of 1.5 - 3.5 % by weight of the core,
wherein erosion of said erosion matrix permits controlled or sustained release of said active substance."
11. In claim 1 of auxiliary request 1, the rate-controlling agent (component ii) of the matrix) is specified as follows (emphasis added to highlight the difference to the main request):
ii) 1-50 % by weight of one or more rate-controlling agents, wherein the rate-controlling agent is a water-soluble polymer;
12. The active substance defined in feature i) is not a critical issue in the present proceedings. The active substance of the claimed pharmaceutical formulation, a coated tablet, is released in a controlled or sustained manner, in the gastric environment of the patient. The "enteric coating" is resistant to gastric acid and prevents dissolution or disintegration in the patient's stomach. In the body region where the active substance is released, the "rate-controlling agent", in which the active substance is embedded, provides for the claimed "controlled or sustained release" of the active substance.
13. The "matrix" formed by the active substance (i) and the rate-controlling agent (ii) is referred to as "erosion matrix", and "erosion" permits the controlled or sustained release of the active substance, according to claim 1.
14. The relevant technical issues of the claimed subject-matter, in view of the prior art, can be summarised as follows:
(a) the claimed amount of the enteric coating, which is smaller than in the prior art;
(b) the variability of the pharmacokinetic parameters of the individual tablets (expressed as the coefficient of variation, i.e. the ratio of the standard deviation to the mean, see paragraph [0045] of the patent); and
(c) the dissolution release profile or kinetic model, i.e. the amount of released active substance over time (see paragraphs [0162] to [0166] of the patent). Three kinetic models are described in said passage, the first referred to as "zero order". In the course of the proceedings, zero order was understood to refer to the release of active substance at a constant rate.
15. Paragraphs [0162] to [0166] form the only passage in the patent specification that refers to kinetic models. Neither "zero order" nor any of the other kinetic model is referred to otherwise; and they are not brought into connection with any technical feature of the claimed tablets or the prior art.
Discussion of the relevant grounds and evidence in appeal
16. The written reasons show that, with respect to the main request, the Board essentially endorsed the view it had already expressed in its communication. In particular it considered that
- D1 disclosed an erosion matrix permitting controlled release;
- the erosion matrix of claim 1 was not limited to any specific kind of release profile, in particular not a zero order profile;
- the only distinguishing feature over D1 was the amount of enteric coating;
- the technical problem was merely the provision of an alternative composition, since the improvement alleged by the proprietor, i.e. the reduced variability in pharmacokinetic parameters had not been credibly demonstrated;
- the choice of the specific amount of coating was an arbitrary choice and, as a routine modification, obvious for the skilled person.
17. With respect to auxiliary request 1, the Board's decision on inventive step, which gave rise to the petition, can be summarized as follows:
- D1 (example 16) remained the closest prior art;
- the objective technical problem was not the one proposed by the proprietor, i.e not the provision of an improved pharmaceutical formulation with a reduced variability in its pharmacokinetic parameters;
- the technical problem was rather the provision of a pharmaceutical formulation showing zero order release, and it was solved by the claimed subject-matter by means of the combination of water-soluble rate-controlling polymers and the thin enteric coating (point 5.4 of the Reasons, two last paragraphs);
- the solution would not have been obvious.
18. For the reasons given below, the Enlarged Board comes to the conclusion that the Board based its decision only on grounds that were objectively foreseeable by the parties, in view of their submissions and the Board's statements during the appeal proceedings.
19. During the entire proceedings leading to the decision under review, the zero order release profile - the provision of which was eventually adopted by the Board as the objective technical problem - was discussed, either as a quality of the erosion matrix or as a feature that was desirable per se. In its grounds of appeal, the petitioner stated in paragraph (50): "Moreover, zero-order release results in constant plasma concentrations of a drug and is consequently generally desirable for extended release formulation."
20. In the decision under review, zero order release was discussed in the context of the question as to whether and in what respect the subject-matter of claim 1 of the main request could be distinguished over example 16 of document D1. The Board did not follow the proprietor's position that D1 did not relate to erosion matrices and that the erosion matrix required by claim 1 necessarily provided a zero order release profile. The Board concluded that "the erosion matrix and supposedly linked release profile cannot constitute a further difference between the claimed subject-matter and the disclosure of D1" (point 1.2.2 of the Reasons).
21. In this context, the Board relied on Figure 1 of the patent, acknowledging that it showed the release of tablets having a zero order release profile. The Board, however, pointed out that the figure referred to specific examples of the patent, all of them comprising hydroxy propylcellulose, a water-soluble polymer, as rate-controlling agent. The functional feature "rate-controlling polymer" remained a general term, in the view of the Board, which did not reflect the specific type of (water-soluble) polymer used in the examples of Figure 1 (point 1.2.2 of the Reasons).
22. From this reasoning concerning the main request, it may already be concluded that there was a connection between the sort of polymer and the release profile.
23. In the course of review proceedings, the proprietor argued that, from reading section 1.2.2 of the decision, it was evident that the technical effect of zero order release was presented with the sole purpose of having it acknowledged as a distinguishing feature, and, therefore, it was obvious to put forward that effect for incorporation into the objective technical problem (letter of 1 October 2020, point 5.1). The petitioner replied to this argument as follows: "The patentee's position is essentially that the arguments they made in relation to the distinguishing feature for the main request disclosed the problem as defined by the TBA for the first auxiliary request" (letter of 5 November 2020, point (11)).
24. One has to conclude, from the file, that the discussion on the main request covered the zero order release profile in connection with the disputed distinguishing feature, the erosion matrix. Not only the problem eventually used in the context of auxiliary request 1 (to achieve a zero order release profile) but also the solution (the use of a water-soluble polymer) was explicitly discussed in the context of the main request. According to the minutes of oral proceedings before the Board, inventive step was discussed for both the main request and auxiliary request 1, before oral proceedings were interrupted for the Board's deliberation. The parties did not know the Board's conclusion on the main request, when auxiliary request 1 was discussed.
25. In situations in which requests are increasingly restricted in a converging manner (e.g. in view of specific examples or embodiments), the parties should be aware that certain effects of the claimed invention may be acknowledged by the deciding organ only for a higher-ranking request.
26. It must be concluded that the facts and evidence underlying the Board's decision on auxiliary request 1 were discussed in a way that gave the petitioner sufficient opportunities to be heard. As shown in the Board's reasons concerning the main request, the distinguishing feature "erosion matrix" and the relation of this feature with the release profile was discussed (see also points 22 ff above), although with the conclusion that "the erosion matrix and supposedly linked release profile cannot constitute a further difference between the claimed subject-matter and the disclosure of D1" (point 1.2.2 of the Reasons). However, the Board's reasons concerning the main request indicate how the additional distinguishing feature could be established, namely, by the use of a water-soluble polymer as a rate-controlling agent. In particular, it was noted that the examples depicted in Figure 1 of the patent, which showed a zero order release profile, comprised a water-soluble polymer (top of page 13 of the decision).
27. These considerations by the Board were based on discussions during written appeal proceedings. In its letter of 28 March 2019, the proprietor explained, in the context of auxiliary request 1, that examples 18 and 22 (as shown in Figure 1 of the patent), for which clinical data were provided, both employed water soluble polymers for rate control. Under these circumstances, it could not be surprising that the Board connected the additional limiting feature of claim 1 of auxiliary request 1 ("wherein the rate-controlling agent is a water-soluble polymer") with the generally acknowledged advantages of a zero-release profile, which profile was also set out for examples 18 and 22 in Figure 1 of the patent.
Conclusion
28. The Enlarged Board concludes that no fundamental violation of Article 113 EPC occurred, since the parties had the opportunity to comment upon the grounds and evidence on which the decision under review is based, in particular, on the additional limiting feature of auxiliary request 1 and the technical effect eventually used by the Board in its application of the problem-solution approach.
R 12/20 is online since October:
ReplyDeletehttps://register.epo.org/application?documentId=M1UO9T0F1AWQNQH&number=EP13820710&lng=en&npl=false