T 0662/02 (Divisible Tablet/TAKEDA CHEMICAL) 27-09-2005

I. European patent EP-0 531 964, based on application No. 92 115 410.0, was granted on the basis of three claims.

Independent claim 1 as granted read as follows:

"1. A tablet of round or oval configuration comprising

first and second surfaces opposite to each other and a side surface lying perpendicular to any one of the first and second surfaces;

a peripheral edge delimited between each of the first and second surfaces and the side surface, said peripheral edge being chamfered to provide a respective inclined edge face over the entire perimeter of the tablet;

a first generally V-sectioned score defined on the first surface so as to leave two tablet divisions of uniform size on respective sides of the first V-sectioned score;

a second generally V-sectioned score defined on the second surface in alignment with and parallel to the first V-sectioned score and wherein said V-sectioned side scores are also continued at the opposite end to opposite ends of the second V-sectioned score;

characterized by a pair or [sic] generally V-sectioned side scores defined on the side surface of the tablet at respective locations opposite to each other and continued at one end to opposite ends of the first V-sectioned score, wherein each of said side scores has a groove depth within the range of 7 to 20% of the length of the first score."

Independent claim 2 as granted read as follows:

"2. A tablet of round configuration comprising

first and second surfaces opposite to each other and a side surface lying perpendicular to any one of the first and second surfaces;

a peripheral edge delimited between each of the first and second surfaces and the side surface, said peripheral edge being chamfered to provide a respective inclined edge face over the entire perimeter of the tablet;

first and second generally V-sectioned scores defined in the first surface so as to extend perpendicular to each other while leaving two tablet divisions of uniform size on respective quadrants defined by the transversely extending first and second scores;

third and fourth generally V-sectioned scores defined on the second surface so as to extend perpendicular to each other and in alignment with and parallel to the first and second scores, respectively, and wherein said V-side scores are also continued at the opposite end to opposite ends of the first and second scores;

characterized by two pairs of generally V-sectioned side scores defined in the side surface of the tablet at respective locations opposite to each other and continued at one end to opposite ends of the first and second scores, wherein each of said side scores has a groove depth within the range of 7 to 20% of the length of any one of the first scores."

II. The following documents inter alia were cited during the proceedings:

(1) Physicians' Desk Reference, 19th ed., Medical Economics Inc., 1964; Product Information XX, 438-Schering-897 "Naqua" Tablets

(2) Physicians' Desk Reference, 42nd ed., Medical Economics Inc., 1988, p. 428, Schering "Naqua**(r)" Tablets

(3) US-A-4 258 027

(4) Excerpt from "Die Pharmazeutika Bestimmungsliste", 6th ed., IMP Kommunikationsgesellschaft mbH, Neu-Isenburg, Germany, 1989, Tavor**(r) and Ergocalm**(r) tablets

(8) US-A-4 824 677

(11) Drawing for "Tavor-Tabs 2,0 mg" from the Notter company (Notter GmbH Werkzeugbau) dated 20 May 1987, filed as an annex together with the drawings of the stamps for producing the tablets ("Anlage N2") to the appellant's letter of 3 September 2002.

III. Opposition was filed and revocation of the patent in its entirety was requested pursuant to Article 100(a) EPC on the grounds of lack of novelty and lack of inventive step.

IV. The appeal lies from the decision of the opposition division rejecting the opposition under Article 102(2) EPC.

The opposition division considered that the subject-matter of claims 1 to 3 as granted was novel over the Naqua**(r) tablet shown in documents (1) and (2), since the pictures depicted therein showed only the top (or bottom) surface of said tablet. The assumption that both surfaces were to be identical could not be made. In this context the opposition division did not accept the statement of 2 November 1999 by MediMedia Medizinische Medien Informations GmbH, Neu-Isenburg, Germany. This analysis also applied to the pictures shown in document (4). Accordingly, the opposition division considered that the only information which was unambiguously derivable from documents (1), (2) and (4) was the overall configuration of the top and side surfaces of the Naqua**(r) and Tavor**(r) tablets respectively at the date of publication of said documents.

Moreover, it was not possible in the opposition division's opinion to determine without ambiguity from the bad quality of the pictures whether or not there was a gap separating each of the ends of the top surface scores from the end of the closest side surface scores in the Naqua**(r) tablets or whether the side scores of the Tavor**(r) tablets were indeed V-shaped.

Furthermore, the opposition division was of the opinion that since the date of manufacture of the sample of Tavor**(r) tablets submitted by opponent II was unknown, it could not be considered to be an accurate reproduction of the Tavor**(r) tablet which was publicly available at the priority date of the contested patent.

Additionally, the opposition division stated that opponent I had not provided any evidence to prove unambiguously that the Naqua**(r) tablet depicted in documents (1) and (2) was indeed available on the market at the priority date of the contested patent.

Moreover, the opposition division considered that the subject-matter claimed in the patent as granted met the requirements of inventive step since the structural features of the tablet appearing in claim 1 were not rendered obvious by the cited prior art, in particular by the Tavor**(r) tablet of document (4) which was identified by the opponents as closest prior art.

V. The appellant (opponent I) lodged an appeal against said decision and filed grounds of appeal and new evidence as an annex to its letter of 3 September 2002 ("Anlage N2": letter from the company Wyeth of 21 August 2002 with the attached annexes corresponding to the drawings of the stamps and the drawing of the form of the tablet Tavor-tabs 2,0mg by company Notter for company Wyeth, numbered as document (11)).

VI. The respondent contested the appeal with arguments.

VII. A communication from the board was sent as an annex to the invitation for oral proceedings.

VIII. Oral proceedings were held before the board on 27 September 2005.

IX. During the oral proceedings, the respondent requested that the appeal be dismissed, i.e. that the patent be maintained as granted. He further requested that the patent be maintained on the basis of the set of claims filed with the letter of 7 August 2000 as auxiliary request.

Claim 1 of the first auxiliary request differs from claim 1 as granted only in the following passage introduced at the end of the claim:

"so that the length of the joint between the tablet pieces obtainable by dividing the tablet is greater than double the length of each side groove as measured along the direction of thickness of the tablet."

X. The appellant had no comments on the novelty of the subject-matter claimed.

With respect to the public availability of the drawing shown in document (11) the appellant stated that company Notter had made it for company Wyeth in order to produce the Tavor tablets. There was no confidentiality agreement between the two companies as shown by the letter from company Wyeth filed as an annex to the reply of 9 September 2005.

The appellant's arguments in respect of the inventive step of the claimed subject-matter may be summarised as follows.

The problem to be solved as stated in the patent in suit was to provide a tablet which could be divided into two identical pieces without breaking into small pieces (paragraph [0009] of the patent in suit). This problem had already been solved by document (8) and the Tavor**(r) tablets. Therefore the problem to be solved was to provide an alternative tablet to those known. The solution as defined in the claims related to the presence of a pair of V-sectioned side scores defined on the side surface of the tablet at respective locations opposite to each other and continued at one end to opposite ends of the first V-sectioned score, wherein each of said side scores had a groove depth within the range of 7 to 20% of the length of the first score.

The appellant developed two alternative routes for the inventive step analysis: either starting from document (8) and then combining it with the teaching of document (3) or starting from the Tavor**(r) tablets and further using the teaching of document (3).

The appellant's further arguments were as follows. It was irrelevant that the Tavor**(r) tablet had three scores on the top surface and three scores on the bottom surface since the condition relating to the division into two tablet pieces of uniform size was met when breaking the tablet using the score in the middle.

Document (3), Figure T, showed a round tablet with peripheral chamfered edge and having scores on the top and side surfaces. It was evident from Figure T in document (3) that the proportion between the groove depth of the side scores and the length of the score of the top surface corresponded more or less to the values given in claim 1 of the main request. Moreover, since there was no effect shown for the specific range of 7-20%, this feature did not contribute to the presence of an inventive step.

Furthermore, the difficulties encountered when breaking a tablet were dependent not only on the form but also on the composition of the tablet.

In the appellant's opinion a V-sectioned score was a wedge-shaped score, pointing to a sharp edge, but it included those scores ending in a curved or linear flat end. The all-round V-sectioned score was known from the prior art (8) and it was obvious for the skilled person that it would facilitate the division of the tablet. The chamfered peripheral edges and the V-sectioned score were features known from the tablets disclosed in document (3).

With respect to the first auxiliary request the appellant stated that the arguments put forward for the main request applied mutatis mutandis. Moreover, the condition introduced in claim 1 reflected the proportions of depth of the side groove to the length of the top surface score shown in the tablets depicted in Figure T of document (3).

XI. The respondent contested that it had been proven that the samples of Tavor**(r) tablets provided by the appellant corresponded to the Tavor**(r) tablets depicted in document (4) or (11). Moreover, there was no proof that such tablets had been commercialised before the priority date of the patent in suit.

Additionally, the respondent stated that document (11) did not form part of the state of the art since this document could not be considered to be publicly available due to the fact that company Notter was a contractor of Wyeth for providing the means to produce the Tavor**(r) tablets. In this context the respondent referred to unpublished decision T 799/91 of 3 February 1994. In the respondent's view the drawing of the tablet form shown in document (11), which contained both names Notter and Wyeth, was an in-house drawing between the companies Wyeth and Notter and hence was not publicly available. Furthermore, the respondent argued that the appellant had the burden of proof to demonstrate that the drawing had been made publicly available.

The respondent denied that Notter and Wyeth constituted the public.

The respondent stated that in case the board considered the Tavor**(r) tablet to be publicly available prior art it requested remittal to the department of first instance.

The respondent also referred to decision T 56/87 OJ EPO, 1990, 188 and argued that the values calculated from the pictures and figures of the prior art could not be used to invalidate the contested patent.

The respondent argued that document (8) concerned the provision of a tablet which had very small breaking surfaces in order to address the problem that upon division the new surface led to significant change in the release rate as compared to the whole tablet. Moreover, it was clear from Figures 2, 7 and 11 of document (8) that the score was not V-sectioned. the tablets according to document (8) would not provide for accurate breaking into two identical parts. Additionally, even if starting from the tablets according to document (8), there was no incentive for the skilled person to introduce the several structural modifications - V-sectioned score, chamfered edges, proportion of depth of side score to length of top surface score - which were needed in order to arrive at the claimed invention.

In this context the respondent referred to the additional data filed as Annexes I, II and III to the letter of 7 August 2000. The comparison made in Annex I served to demonstrate the improvement achieved by flat tablets with chamfered peripheral edge (tablet F) when compared to oblong tablets (such as the Tavor**(r) tablet) with a curved surface (tablet R). This conclusion was also valid for tablets having side scores.

In the respondent's opinion the comparison made in Annex I was a valid comparison for demonstrating the presence of an effect achieved by the claimed tablets, since an oblong tablet lay closer to a flat tablet with chamfered edges than a flat tablet without chamfered edges. When a tablet was divided, sharp edges were formed, giving rise to brittle small parts, especially in case of non-chamfered flat tablets. This problem was reduced when breaking, flat tablets with chamfered peripheral edges.

In the respondent's view the problem to be solved lay in the provision of a divisible tablet with superior effect when breaking and the solution related to the combination of the peripheral chamfered edge together with the all-round score. The solution was not rendered obvious by the cited prior art.

The respondent disputed the appellant's definition of a V-sectioned score since in its opinion the wedge-shaped score had to finish in a sharp end.

Furthermore the meaning of V-sectioned score was to be understood in the context of the patent in suit and was shown by the figures in the patent.

With respect to the first auxiliary request the respondent again cited decision T 56/87, which stipulated that specific values could not be derived from a schematic drawing.

XII. The appellant (opponent I) requested that the decision under appeal be set aside and that the European patent No. 0 531 964 be revoked.

The respondent (patentee) requested that the appeal be dismissed, or that the patent be maintained on the basis of the set of claims filed as first auxiliary request on 7 August 2000.