T 2259/22 28-11-2024

1. The subject-matter of the contested patent

1.1 The contested patent relates to a stent-based implant for treating an incompetent or regurgitant tricuspid valve, i.e. a tricuspid valve that does not perform its normal function of preventing the backflow of blood from the right ventricle to the right atrium when it closes during ventricular systole and allowing blood to flow from the right atrium to the right ventricle when it opens during ventricular diastole (paragraphs [0001] to [0003] of the patent).

1.2 An example of an implant (10) according to claim 1 of the main request is shown in Figures 3A, 3B and 4A, reproduced below.

FORMULA/TABLE/GRAPHIC

This implant comprises a tubular vena cava member (12) implantable in the superior vena cava (1) and the inferior vena cava (3) of a patient (see Figure 4A), with a fenestration (14) formed in a side wall of the vena cava member, and a blocking member (16) comprising a flap or cover pivoted to a portion of the vena cava member and arranged to block or unblock the fenestration. In the blocking configuration (see Figure 3B), the tubular vena cava member and the blocking member together have a closed cylindrical shape, as shown in Figure 3B. The implant can also comprise more than one fenestration and corresponding blocking member (see Figures 6 and 7). An overview of the functioning of the implant is given in paragraphs [0009] and [0010].

1.3 This implant provides an alternative to the complex and risky repair/replacement of the tricuspid valve (4) by open heart surgery (paragraphs [0004] and [0005]). For this purpose, rather than mimicking the structure of the tricuspid valve, the implant aims to functionally replace a regurgitant tricuspid valve, while avoiding the complex anatomy of the right ventricle (5) and the valve itself (paragraphs [0007] and [0008]).

2. Request for postponement of the oral proceedings; objection under Rule 106 EPC

2.1 During the oral proceedings before the Board, the opponent stated that it had only become aware of the proprietor's letter of 25 October 2024, in which the proprietor had further discussed the issue of novelty of claim 1 in view of D3, and of the auxiliary request 1a filed with that letter, during the ongoing oral proceedings. The opponent therefore requested that the oral proceedings be postponed - i.e. more precisely, that they be adjourned - to give the opponent sufficient time to consider the proprietor's submissions and to prepare a reply.

2.2 An internal investigation by the Registry following the oral proceedings has indeed revealed that, for some reason, the proprietor's letter of 25 October 2024 was not forwarded to the opponent as would normally have been the case.

2.3 The Board recognises that this is regrettable. However, for the following reasons, the Board considered that this failure, however unfortunate, did not justify the adjournment of the oral proceedings.

The discussion at the oral proceedings did not turn on auxiliary request 1a filed with the letter of 25 October 2024 but was limited to the patentability of the main request. It is true that the letter of 25 October 2024 also comprised submissions on the novelty of the main request in view of D3. However, as discussed in detail in point 3. below, the Board's conclusion that the subject-matter of claim 1 is novel in view of D3 was not taken on the basis of those submissions but rather on the basis of the arguments put forward by the proprietor at the oral proceedings, which supported the view that the implant disclosed in D3 is unsuitable for treating tricuspid insufficiency. The opponent orally replied to these arguments. As can be seen from the minutes of the oral proceedings before the Board and as summarised in point VI. above, it was indeed only at the oral proceedings, after both parties had been heard by the Board on this issue, that the Board took the view that the subject-matter of claim 1 was novel over D3, thus departing from its preliminary opinion expressed in its communication under Article 15(1) RPBA and reiterated at the beginning of the oral proceedings, which was in favour of the opponent.

The issue of whether the implant of D3 is suitable for treating tricuspid insufficiency was of relevance throughout the opposition proceedings (see, for example, point 2 of the minutes of the oral proceedings before the opposition division) and was discussed in the decision under appeal itself (see points 2.3.2.1(i) and 2.3.2.2.1 of the Reasons). At the oral proceedings, the proprietor merely emphasised and refined some of the arguments already put forward on this issue in its statement of grounds of appeal (see in particular point II.2.a and b on pages 5 to 10). Therefore, the proprietor's submissions at the oral proceedings before the Board on this issue - which, moreover, were easily understandable - could not have surprised the opponent.

The fact that some of the arguments put forward by the proprietor at the oral proceedings before the Board may already have been set out in the letter of 25 October 2024 is irrelevant and did not prevent the opponent from commenting on and rebutting these arguments, something the opponent in fact did.

Furthermore, although reference was made to the proprietor's letter of 25 October 2024 and to auxiliary request 1a at the very beginning of the oral proceedings before the Board, i.e. before the actual discussion of novelty in view of D3, the opponent nevertheless made its request for postponement of the oral proceedings only after the Chairman had announced the Board's conclusion that the subject-matter of claim 1 was novel over D3. Up to that point, the opponent never complained that its right to be heard had been violated. Nor did it request an interruption of the oral proceedings to have more time to consider the arguments presented orally by the proprietor or indeed that the arguments be disregarded.

In these circumstances, the Board saw no reason to adjourn the oral proceedings and consequently did not grant the opponent's request to do so.

2.4 The opponent then raised an objection under Rule 106 EPC, claiming that the Board had violated its right to be heard by refusing to adjourn the oral proceedings.

As explained above, the Board's refusal to adjourn the oral proceedings did not prevent the opponent from having the opportunity to address and present its comments on the proprietor's arguments presented at the oral proceedings on the novelty of claim 1 in view of D3, on which the Board's conclusion, as discussed in point 3. below, is based. It follows that, contrary to the opponent's contention, its right to be heard pursuant to Article 113(1) EPC was not infringed. The Board therefore rejected the opponent's objection under Rule 106 EPC.

3. Novelty in view of D3

3.1 Contrary to the opponent's view, D3 does not disclose a device comprising feature 1.1, and the subject-matter of claim 1 is therefore novel in view of D3.

3.2 It is common ground that the expression "tricuspid insufficiency treatment device" in feature 1.1 means nothing other than a device suitable for treating tricuspid insufficiency. Accordingly, any prior-art device which, in addition to including the features expressly mentioned in claim 1, can be used for this purpose will take away novelty from the claimed device. This is irrespective of whether the prior art mentions the stated use or purpose or whether the stated use is obvious. This is because claim 1 is directed to the device and not to its use.

3.3 It is also common ground that D3 does not address the treatment of tricuspid insufficiency. Rather, D3 discloses implants primarily intended for implantation in blood vessels, in particular for treating stenoses or aneurysms. The question therefore arises as to whether the implants of D3 are suitable for treating tricuspid insufficiency.

3.4 As argued by the opponent, these implants, such as the implant shown in Figure 3 reproduced below, comprise, similar to the implant of claim 1, a tubular stent-like member 10 ("rohrförmige Wandung") on which flaps 21 ("Klappen") are pivotally mounted so as to block and unblock multiple corresponding fenestrations 12 ("Zellen") defined in the side wall of the implant, in particular by the struts ("Stegen") 11 of the stent-like tubular member.

FORMULA/TABLE/GRAPHIC

In the embodiment of Figure 3, the flaps are only allowed to pivot outwards, meaning that the implant, like the implant of claim 1, has a valve function in that it allows blood to flow from the inside of the implant to the outside, but not vice versa (page 31, first paragraph: "Rückströmung blockiert"; page 33, second paragraph), in response to corresponding pressure gradients (page 4, second paragraph). In this way, blood can flow from a main vessel 41 in which the implant is implanted into a branched secondary vessel 42, while blood backflow from the secondary vessel 42 into the main vessel 41 is prevented.

3.5 The opponent argued that that this implant could therefore be successfully implanted in a patient's vena cava for treating tricuspid insufficiency, at least to some extent.

The Board disagrees. As argued by the proprietor at the oral proceedings before the Board and as set out below, the suitability of the device of claim 1 for the treatment of tricuspid insufficiency implies various requirements that the implants of D3, which are designed for a completely different purpose and environment, such as the treatment of stenoses and aneurysms in blood vessels, do not meet. This applies even if, as set out above, these implants are designed to have a certain valve function.

It is true that claim 1 does not limit the patient to a specific class of patients or the vena cava in which the vena cava member of the implant must be implantable to have specific dimensions. Therefore, given the great variability of dimensions of the vena cava even within a class of patients, it is indeed conceivable that an implant of D3, such as that shown in Figure 3, may have a diameter suitable for implantation in the superior vena cava and the inferior vena cava of a patient, like the claimed implant shown in Figure 4A of the contested patent.

However, as argued by the proprietor, the implant of D3, especially when designed for use in blood vessels with a stable, constant geometry, would not as such be able to withstand the highly dynamic and mechanically challenging environment of the right atrium and the vena cava, the geometries of which, unlike that of a blood vessel, change significantly with each heartbeat and with each respiratory movement. Firstly, the Board is not convinced that this implant, without some ad hoc modification of its construction - which D3 neither discloses nor suggests - would be able to accommodate these constant variations in shape and withstand the resulting mechanical stresses without deteriorating, in particular due to material fatigue. Secondly, it is also doubtful whether the implant would even remain in place in such a dynamic environment, with a substantial central part of the implant extending into the open space formed by the right atrium, thus leaving it without any support. In contrast, as argued by the proprietor, the implants of D3 are designed to maintain contact with the vessel walls and rely largely on the support of the vessel walls to function properly, with only a limited portion of the implant in the region of the branch left unsupported (see Figure 3).

Furthermore, as the proprietor also argued, the implant of D3, in particular because of its homogeneous structure with flaps uniformly distributed along its length, would not be able to reliably and safely block blood backflow in the highly dynamic vascular environment of the heart. This is because the constant deformation of the stent-like member 10 imposed by this environment would prevent the flaps from reliably blocking and unblocking the fenestrations primarily in response to blood pressure gradients between the vena cava and the right atrium, as expected of a device suitable for treating tricuspid insufficiency.

The Board therefore concludes, in agreement with the proprietor, that the implant of D3 is not suitable for treating tricuspid insufficiency as required by feature 1.1. Hence, the subject-matter of claim 1 is novel in view of D3.

4. Substantiation and admittance of the novelty objections in view of D1, D4, D5 and D8 and the inventive-step objections starting from D1, D2, D3, D5 or D8

Contrary to the proprietor's assertion, the Board does not consider the opponent's further objections to claim 1 to be unsubstantiated.

In point 2.4 of its statement of grounds of appeal, the opponent explained in detail why, in its opinion, "D1 disclose[d] each and every features of claim 1 as granted" (see fourth paragraph on page 6), in other words, why the subject-matter of claim 1 was not novel in view of D1.

It is true that the further novelty objections in view of D4, D5 and D8 and inventive-step objections starting from D1, D2, D3, D5 and D8 are not set out in detail in the opponent's statement of grounds of appeal (see points 2.6 and 2.7). However, for these objections, the opponent referred to specific passages of the notice of opposition, namely points III.A.4. to III.A.6. and III.B.1. to III.B.3., in which the opponent explained in detail why the subject-matter of claim 1 as granted, with which claim 1 is identical, was not novel or not inventive in view of these documents.

This enables the Board to understand without undue burden the reasons why the opponent requested that the decision under appeal concerning claim 1 be reversed or upheld regarding novelty and inventive step in respect of these documents. The Board thus considers that these further objections are substantiated as required by Article 12(3) RPBA, and there is therefore no reason for the Board not to admit them pursuant to Article 12(5) RPBA.

5. Remittal of the case to the opposition division

5.1 The opponent justified its conditional request for remittal of the case to the opposition division on the ground that D4, D5 and D8, which had been cited in the notice of opposition as prejudicial to the maintenance of the patent as granted, had not been considered by the opposition division. The opponent did not comment on this request again at the oral proceedings before the Board.

5.2 It is true that D4, D5 and D8 are not discussed in the decision under appeal. Indeed, as the opposition division found that the subject-matter of claim 1 as granted, with which claim 1 is identical, was not novel in view of another document, D3, there was no need to discuss the further objections to that claim based on D4, D5 and D8.

5.3 Nevertheless, the Board found it appropriate to exercise its discretion under Article 111(1) EPC to examine and decide on these objections itself.

The objections to claim 1 based on D4, D5 and D8 essentially depend on the suitability of an implant for treating tricuspid insufficiency (feature 1.1) and on what the person skilled in the art would consider to be a flap or cover pivoted to a portion of the vena cava member and a corresponding blocking member (features 1.4 and 1.5), i.e. similar issues to those considered in the decision under appeal, in particular as regards D3.

Furthermore, the objections based on D4, D5 and D8 were also addressed by the proprietor in its appeal submissions and by the Board in its communication under Article 15(1) RPBA.

The Board therefore considered that no special reasons under Article 11 RPBA had presented themselves for remitting the case and consequently decided not to remit the case to the opposition division.

6. Novelty in view of D1, D4, D5 and D8

6.1 Contrary to the opponent's view, none of D1, D4, D5 and D8 discloses an apparatus comprising all the features defined in claim 1. The subject-matter of claim 1 is therefore novel in view of all these documents.

6.2 It is common ground that D1 (see figure reproduced below) expressly discloses an implant suitable for treating tricuspid insufficiency (page 3, lines 24 to 26), comprising a tubular vena cava member 11 ("stentartige Tragstruktur") with a lateral opening 12 in which a biological heart valve 15 is arranged.

FORMULA/TABLE/GRAPHIC

However, even assuming, as alleged by the opponent, that the one or more leaflets of the biological heart valve 15 are mounted directly to the vena cava member, D1 does not directly and unambiguously disclose that the vena cava member and the one or more leaflets together have a closed "cylindrical" outer shape as required by feature 1.6.

D1 only discloses that the implant is tubular overall (page 3, last paragraph: "insgesamt rohrförmig"; page 5, second paragraph: "Rohrform"). In contrast, the term "cylindrical" in feature 1.6 requires that the outer shape of the vena cava member together with the one or more flaps is not merely as a whole tubular but also excludes protrusions from the stent graft body. This is in agreement with the description of the contested patent which stipulates "no element protruding towards or inwards from the stent graft body" (paragraph [0014]). The person skilled in the art would understand that this definition does not preclude that the flaps, due to their non-zero thickness, may slightly extend outwards from the outer surface of the tubular vena cava member, as long as they do not "protrude" inwards or outwards.

In the absence of any detailed description of the biological heart valve 15 in D1, the Board finds persuasive the proprietor's argument that, as a conventional biological heart valve, valve 15 may not be planar but instead seems to have a three-dimensional, tapered structure with a non-zero height to allow the leaflets (or parts of the single leaflet in the case of a monocuspid valve) to abut during coaptation, when the valve is closed. The valve therefore in this case constitutes an element which protrudes outwards from the vena cava member, meaning that the outer shape of the implant of D1 is not "cylindrical".

It follows that D1 at least does not directly and unambiguously disclose feature 1.6.

6.3 It is common ground that D4, D5 and D8 do not address the treatment of tricuspid insufficiency. Rather, like the implants of D3, the implants disclosed in these documents are primarily intended for the treatment of stenoses and aneurysms (see for example paragraph [0008] of D4; paragraphs [0004] to [0009] of D5; paragraph [0002] of D8).

Although these documents disclose that the implants might be used for other parts of the body, as argued by the opponent, the opponent's allegation that these implants are suitable for treating tricuspid insufficiency is not convincing. For reasons similar to those discussed for D3, the Board agrees with the proprietor that these implants could not be successfully used for this purpose without being specifically modified, something which D4, D5 and D8 neither disclose nor suggest. The opponent has not provided any convincing arguments to the contrary. It follows that D4, D5 and D8 do not disclose at least feature 1.1.

6.4 Furthermore, the implant of D4 shown in Figure 2B comprises a continuous helical stent member 280 and a continuous helical membranous covering 290 which together define the peripheral wall of a tunnel while allowing outward radial flow through this wall from the interior of the tunnel to the exterior. Contrary to the opponent's argument, this does not anticipate a blocking member comprising a flap or cover pivoted to a portion of the stent member, and adapted to block and unblock a corresponding fenestration formed in the side wall of the stent member (features 1.3 to 1.5).

The implant of D8 is designed for the treatment of type II endoleaks (paragraph [0002]). As shown in Figures 21 and 22, this implant is bifurcated and comprises two branch portions 185, 186, this making it unsuitable for implantation in a vena cava. D8 therefore does not disclose a vena cava member adapted to be implanted in a vena cava (feature 1.2).

7. Inventive step starting from D1 or D2

7.1 Contrary to the opponent's view and as set out below, the subject-matter of claim 1 involves an inventive step starting from D1 or D2.

7.2 As set out in point 6.2 above, the subject-matter of claim 1 differs from the implant of D1 at least by virtue of feature 1.6.

7.3 Similarly, it is common ground that D2 discloses (see Figures 2 and 3) a device for treating tricuspid insufficiency similar to the implant of D1, comprising a biological heart valve 40 laterally mounted on a tubular stented vena cava member 30 (see paragraph [0049]).

As the biological heart valve 40 projects outwards from the lateral surface of the vena cava member 30 (all the more so as the valve 40 is expressly a "stented" valve), these two parts together do not have a cylindrical outer shape as required by feature 1.6. It follows that the subject-matter of claim 1 also differs from the implant of D2 by virtue of feature 1.6.

7.4 Referring to paragraph [0030] of the contested patent, where the advantage of the closed cylindrical outer shape of the claimed device resulting from this feature is emphasised, the opponent formulated the objective technical problem to be solved starting from D1 as facilitating the sheathing and unsheathing of the device when loading and deploying it on a delivery catheter.

7.5 Even assuming this objective technical problem - which is contested by the proprietor - the Board is not convinced that the person skilled in the art, starting from D1 or D2 and faced with this problem, would have implemented feature 1.6 in the implant of D1 or D2 in an obvious manner and without hindsight, even taking into account D3.

Firstly, it is already questionable whether, as the opponent argued, the person skilled in the art starting from D1 or D2 would have consulted D3 at all, which does not relate to the treatment of tricuspid insufficiency but discloses implants with a completely different purpose and different construction (see section 3. above).

Most importantly, the Board agrees with the proprietor that the person skilled in the art starting from D1 or D2 would in any event not have departed from a biological heart valve, which is consistently presented to be at the core of the inventions of D1 and D2. Consequently, the person skilled in the art would not have combined D1 or D2 with D3 as alleged by the opponent since this would have required replacing the biological heart valve with a different construction based on one or more flexible flaps as disclosed in D3.

Rather, the person skilled in the art seeking to facilitate the sheathing and unsheathing of the implants of D1 or D2 in a delivery catheter would have modified the stent-like vena cava member to make it even more compressible, as indeed is suggested in D1 itself (page 8, first paragraph, last sentence), or would have mounted the biological heart valve deeper in the lateral opening of the vena cava member to minimise the extent of its lateral protrusion. However, none of these measures would have resulted in feature 1.6.

8. Inventive step starting from D3, D5 or D8

8.1 The opponent's inventive-step objections in respect of D3, D5 and D8 are based on the argument that the person skilled in the art, faced with the technical problem of providing a device suitable for treating tricuspid insufficiency, would naturally have considered using for this purpose the implants disclosed in these documents, even if the latter do not contain any indication to that effect.

8.2 The Board disagrees. As discussed in points 3.5 and 6.3 above, and contrary to the opponent's view, the implants disclosed in D3, D5 and D8 are not suitable to be implanted in a vena cava for the treatment of tricuspid insufficiency unless they are specifically modified for this purpose. In the absence of any disclosure or suggestion to that effect in these documents, the person skilled in the art starting from one of these documents would not, without the benefit of hindsight, have considered such modifications. For this reason alone, the opponent's objections are not convincing.

8.3 When looking for a device suitable for treating tricuspid insufficiency, the person skilled in the art would have instead chosen one of the implants disclosed in D1 or D2, not least because, in contrast to the implants of D3, D5 and D8, these implants are explicitly designed - and disclosed as such - as devices for treating tricuspid insufficiency. However, in doing so, the person skilled in the art would not have arrived at the subject-matter of claim 1, as set out in section 7. above.

8.4 The Board therefore agrees with the proprietor that the subject-matter of claim 1 involves an inventive step starting from D3, D5 and D8.

9. Conclusion

It follows from the foregoing that none of the objections raised by the opponent prejudice the maintenance of the contested patent as amended on the basis of the main request, contrary to the finding in the decision under appeal.