T 0762/07 (Estrogen receptor/ORGANON) 24-02-2009

Reasons for the Decision

Admissibility of the main request

1. Appellant I's submission that a patentee may always revert to the granted claims is, with one exception, correct. In decision T 386/04 of 9 January 2007, which made a thorough review of the relevant case law, it was said (see Reasons, point 1):

"There is therefore nothing in principle to prevent a patentee from later seeking to amend his request so as to ask for the patent to be maintained in the form as granted (or in more limited terms), either in the course of proceedings before the opposition division or on appeal. Indeed, he is entitled to as of right.... The exception to this principle is where it would amount to an abuse of procedure to allow the proprietor to revert to the granted claims."

2. Thus, the argument of Appellants II and III that the patentee in this case abandoned the granted claims is exaggerated. The patentee was perfectly entitled to file other claims in response to the notices of opposition and, at a later date, to revert to the granted claims in an attempt to avoid the opposition division's opinion and to take advantage of the decision in G 01/03 (supra) which had been issued meanwhile. However, Appellant I's arguments are also exaggerated. Its submissions that the opponents could have anticipated a further change of claims and that it was not to blame if the opponents could not see that re-introduction of the granted claims was the most elegant way to avoid the opposition division's opinion are disingenuous. Any party is entitled to rely on the position another party expressly adopts as being its true position and to have proper notice of any change in such position. Patent proceedings are not guessing-games.

3. The board must decide, ignoring the parties' exaggeration, whether or not the patentee's behaviour was an abuse of procedure such as to deny it the right to revert to the granted claims. In this respect the board has not read or heard any submissions from the parties which change the provisional view it expressed in its communication of 10 July 2008, namely that while it was understandable that the patentee might have had second thoughts after decision G 01/03 (supra) was issued, it was equally understandable that the opponents could infer from the lapse of two years thereafter that the patentee would not revert to a disclaimer in reliance on G 01/03 (supra), and that the most important factor was that the patentee gave no indication of second thoughts until the opening of the oral proceedings on 28 March 2006.

4. That the change of main request was not announced earlier because the need to change was only noticed by the new representative is not an acceptable reason for either surprise or lateness - the opponents had nothing to do with either the change of request or the change of representative. Any notice, however short, would have been better than none but the patentee elected to keep the change to itself until the last possible moment. That is not how litigation should be conducted: cards should be put on the table, not kept up the sleeve. Contrary to Appellant I's argument, depending on the circumstances any change - even reverting to granted claims - can be a surprise and can be late-filed.

5. Appellant III referred to T 446/00 of 3 July 2003 in which a patentee specifically stated, in answer to a challenge from the opponent, that it would not rely on a certain claim and then later re-introduced that claim without explanation. That was held to be an abuse of procedure (see Headnote 2 and Reasons, points 4.1.1, 4.1.2 and 4.5.3). In the present case there was no such specific retraction, but the effect of three years silence broken only at the very last possible opportunity must be viewed as having much the same effect. In T 1449/03 of 26 September 2006, a patentee's departure for the first time at oral proceedings from a position previously and persistently held was not allowed inter alia because the opponent might have been lulled into a feeling of false security (see Reasons, points 2.8 and 2.9).

6. In all the circumstances, the board finds that the manner in which Appellant I reverted to the claims as granted was an abuse of procedure which the opposition division should not have allowed. It follows that the same request should not be admissible on appeal since otherwise Appellant I would be allowed to avoid the consequences of its abuse of procedure. Article 12(4) RPBA specifically refers to the power of the board to hold inadmissible requests which were not admitted in first instance proceedings; that power must inevitably extend to requests which were admitted by a decision of the first instance which is over-ruled on appeal.

First auxiliary request; claim 1

Articles 123(2)and 54 EPC; admissibility of the disclaimer,

novelty

7. Claim 1 relates to estrogen receptors identified by their percentages of homology to the human ERß estrogen receptor over two specific domains of the molecule, the DNA binding domain and the ligand binding domain. It contains a disclaimer of the specific rat ERß protein sequence disclosed in document (4) (Fig.1).

8. Document (4) is a patent application to be taken into account for the purpose of assessing novelty under Article 54(3) EPC, inasmuch as it enjoys priority from the two priority documents GB 9518272.1 and GB 9605550.4 respectively filed on 8 September 1995 and 15 March 1996, that is, earlier than the filing date of the earliest priority document of the patent in suit, EP 96200820 filed on 26 March 1996. It was published on 13 March 1997, i.e. shortly before the filing date of the patent in suit (25 March 1997).

9. Document (4) discloses not only the now disclaimed specific rat ERß protein sequence but it mentions also on page 4 that:

"An amino acid sequence which is more than about 89% identical with the sequence shown in Fig.1 ... is substantially the same amino acid sequence for the purposes of the present application", and

"An amino acid sequence functionally similar to the sequence shown in Fig.1 ... may be from a different mammalian species."

10. The Enlarged Board of Appeal's decision G 01/03 (supra; point 2.1 of the Order) establishes the purpose of a disclaimer:

"A disclaimer may be allowable in order to:

- restore novelty by delimiting a claim against state of the art under Article 54(3) and (4) EPC."

11. The point to be decided when assessing whether the disclaimer in claim 1 is allowable is, thus, whether or not it delimits the claimed subject-matter from the above mentioned teachings on page 4 of document (4). Otherwise stated, should a sequence being 89% identical to the rat ERß sequence be regarded as a sequence with at least 80% homology to the human ERß sequence in its DNA binding domain (SEQ ID NO:3) and with at least 70% homology to the human ERß sequence in its ligand-binding domain (SEQ ID NO:4) ?

12. A comparison of the rat ERß and the human ERß DNA binding domains (Fig.1, document (4) and SEQ ID NO:3) shows them to be 98.5% identical (one difference over 66 amino acids). A comparison between the rat ERß and the human ERß ligand-binding domains (Fig.1, document (4) and SEQ ID NO.4) shows them to be 92.7% identical (17 differences over 233 amino acids). It follows therefrom that molecules with 89% identity to rat ERß have 87.6% (98.5 x 89) identity and 82.5% (92.7 x 89) identity with, respectively, the DNA- and ligand- binding domains of human ERß. Such molecules are, of course, molecules with at least 80% homology to the DNA binding domain, SEQ ID NO:3 and at least 70% homology to the ligand binding domain, SEQ ID NO:4. They, thus, fall within the scope of the claim.

13. Appellant I argued that the disclosure in document (4) of molecules with 89% identity to the rat ERß molecule was a generic disclosure which, as such, could not take away the novelty of the claimed molecules identified by their percentages of homology to the human ERß molecule over specific domains which, as such, had to be considered a more specific disclosure than the disclosure in document (4). The board does not find this argument convincing. Disclosing an 89% identity to rat ERß would be understood by the skilled person as meaning that this percentage of identity is achieved over the length of the molecule. Indeed, there is no reason to believe that the 89% identity would be unevenly distributed with a percentage of identity higher than 89% being found in the domains other than the DNA- and ligand- binding domains and with a percentage of identity lower than 89% being found in these last two domains. In fact, it is even the contrary which could be expected to happen, since the N-terminal region (domains A/B) is highly variable in size and sequence whereas the DNA binding domain (domain C) is highly conserved and the ligand binding domain (domain D) is moderately conserved (patent in suit, page 3, [003] to [006]). Thus, as shown above, document (4) discloses molecules with 87.6% and 82.5% identity to the human ERß sequence in the DNA- and ligand- binding domains; this disclosure is no more generic than the definition of the claimed molecules. In fact, it could even be seen as more specific since "identity" is a narrower feature than "homology".

14. For the reasons given in point 12, supra, the disclaimer is considered to be insufficient to delimit the claimed subject-matter from the teachings of document (4).

15. A further argument was presented by Appellant II as to why the disclaimer may not be allowable, namely that it should have been inserted in the text of the application as filed which is the basis for the patent in suit because document (4) was published on 13 March 1997 i.e. before the filing date of said application. Although dealing with this point is not strictly necessary in view of the findings in point 14, supra, the following observations are made. Article 54(2)(3) EPC reads as follows:

"(2) The state of the art shall be held to comprise everything made available to the public by means of a written or oral description, by use, or in any other way, before the date of filing of the European patent application.

(3) Additionally, the content of European patent applications as filed, the dates of filing of which are prior to the date referred to in paragraph 2 and which were published on or after that date, shall be considered as comprised in the state of the Article"

As for Article 89 EPC, it establishes that:

"The right of priority shall have the effect that the date of priority shall count as the date of filing of the European patent application for the purposes of Article 54, paragraphs 2 and 3, and Article 60 paragraph 2."

Reading these articles of the law in combination leaves absolutely no doubt that the provisions of Article 89 EPC are to be applied before those of Article 54 EPC.

16. In the present case, the effective filing date of the patent in suit is, thus, either one of its priority dates i.e. 22 November 1996 or 26 March 1996 and document (4) is certainly not a pre-published document, the teaching of which would have had to be disclaimed in the application as filed. Appellant II's argument is, thus, irrelevant.

17. As the disclaimer is not allowable under Article 123(2) EPC (see point 14 supra), the subject-matter of claim 1 lacks novelty under Article 54(3) EPC over the teachings of document (4).

Auxiliary request IIb; claim 1

Article 123(2) EPC; admissibility of the disclaimer

18. The disclaimer in claim 1 now comprises sequences which are more than 89% identical with the rat ERß protein sequence. At oral proceedings, Appellant II presented for the first time the argument that while document (4) disclosed molecules which were more than 89% identical with the rat ERß protein, this disclosure did not enjoy priority because in the relevant first and second priority documents pertaining to document (4), it was molecules with 90% identity with rat ERß which were disclosed. Therefore, in its view, the "more than 89% identity" was not a disclosure under Article 54(3) EPC and the disclaimer in fact removed more than was necessary to establish novelty. For this reason and following the principle established in point 3 of the decision G 01/03 (supra) that a disclaimer should not remove more than was necessary to establish novelty, the disclaimer in claim 1 should not be allowed.

19. This argument is a fully new argument and what would be the relevant evidence, namely the first and second priority documents pertaining to document (4), is not on file. As it stands, this appraisal of document (4) was even "left aside" by appellant II itself during the oral proceedings when the first auxiliary request was discussed. Then, appellant II took the view that the disclaimer of "only the specific rat ERß" was not allowable under Article 123(2) EPC since such case law as T 1120/00 (supra) established that a disclaimer was not properly drafted when it failed to comprise the intermediate generalisations (i.e. sequences defined by way of homology to a given specific sequence) which an intermediate document may contain. In document (4), the intermediate generalisation is precisely molecules with 89% identity to the rat ERß specific sequence. Under the circumstances, the board decides to disregard the argument as being both late filed and not properly substantiated.

20. Appellants II and III further argued that the disclaimer was not sufficient because it failed to mention molecules functionally related to rat ERß, a teaching to be found on page 4 of document (4) (see point 9, supra). However, this teaching is so vague that it is totally unclear whether or not it covers any molecules falling within the scope of claim 1. For this reason, there is no need to disclaim it.

21. It is concluded that the disclaimer in claim 1 fulfils the requirements of Article 123(2) EPC.

Article 84 EPC, clarity

22. In accordance with the case law (see e.g. T 190/99 of 6 March 2001), a patent must be construed by a mind willing to understand, not a mind desirous of misunderstanding. In the board's judgment, the person skilled in the art would find it perfectly clear that the expression "a sequence which is more than 89% identical with that sequence" found at the end of the disclaimer was part of the disclaimer and that the term "that sequence" within it referred to the specific rat ERß sequence directly above, which is also part of the disclaimer.

23. Whereas it is true that two "measuring systems" (percentage of identity vs. percentage of homology) are used in claim 1, this does not introduce a lack of clarity because firstly, there is no doubt as to with which molecules the identity or homology criteria should be used and, secondly, standard methods were known in the art to establish percentages of homology.

24. It is concluded that the requirements of Article 84 EPC are fulfilled and furthermore that since the disclaimer is allowable under Article 123(2) EPC, the claimed subject-matter is novel under Article 54(3) EPC over the teachings of document (4).

Article 56 EPC; inventive step

25. The closest prior art is the oral disclosure by Prof. J-A. Gustafsson on 22 March 1996 at the Keystone Symposium - Nuclear Receptor Superfamily as reflected by document (9), namely the notes taken by Dr U. Fuhrmann who was a member of the public attending the presentation. As would be expected, these notes are written in very much of a short-hand style. However, it has not been disputed that they convey the following information :

A novel estrogen receptor (ERß) DNA had been cloned from rat prostate tissue. The ERß protein showed 95% identity to the prototype of the hormone receptor family, identified as ER or as alpha, in the DNA binding domain and 55% identity to this protein in the ligand binding domain. A corresponding ERß receptor existed in human tissues such as prostate, ovaries, uterus tissues, even in the central nervous system. The ERß receptor DNA of human origin had been or could be cloned with the help of a rat DNA probe.

26. It should be noted that post-published document (18), only to be taken as an expert opinion, also reported the same information when reviewing what had been disclosed at the symposium.

27. Starting from the closest prior art, the problem to be solved may be defined as reducing to practice the suggestion made by Prof. J-A. Gustafsson during his presentation (cf. document (9)) of isolating human ERß DNA/human ERß receptor protein.

28. The solution provided is to isolate ERß cDNA from a human testis cDNA library using primers, the sequences of which were derived from an ERß cDNA fragment, itself isolated from a cDNA library from human peripheral blood leukocytes. This fragment was obtained by using degenerate primers based on conserved regions of the DNA binding and ligand binding domains of the human hormone receptor family (patent in suit, Example A, [0059] to [0065]).

29. As the presence of ERß in human tissues was known from the presentation of Prof. J-A. Gustafsson (cf. document (9)), the fact of attempting to isolate ERß DNA from human tissues does not in itself contribute to inventive step. The issue to be decided is whether or not the person skilled in the art would have had a reasonable expectation of success when doing so. It is noted in this respect that Prof. J-A. Gustafsson during his presentation (cf. document (9)) provided the information that the rat ERß protein is 95% identical to the prototype of the hormone receptor family, namely ERalpha (sequence described in prior art document (2)), in the DNA binding domain and that there also exist 55% identity between the two in the ligand binding domain. For the skilled person, that must have been a most useful item of information because it suggested that human ERß could be expected also to have a high degree of identity to prototype ERalpha. Of course, the observation made by Prof. J-A. Gustafsson during his presentation (cf. document (9)) related to sequence identity at the protein level. Yet, the percentages of protein sequence identity which he mentioned were high enough to strongly encourage the use of oligonucleotide primers derived from conserved regions in the DNA- and ligand- binding regions of members of the hormone receptor family (ERalpha). In fact, this was the strategy used in the patent in suit in the first step in the cloning of the human ERß DNA (see point 23). It was never argued that once an initial ERß DNA fragment had been isolated, any difficulties had been encountered in carrying out the cloning to its end.

30. Appellant I would seem to regard the use of a cDNA library from human testis tissue as indicative of inventive step, remarking that a successful post-published attempt at cloning human ERß DNA (document (21)) had also made use of testis tissue as starting material. In this respect, a first observation is that the ERß cloning as described in the patent in suit was initiated with a cDNA library from human peripheral blood leukocytes. This certainly goes against the idea that the use of a testis cDNA library in the last steps of the experiment was a purposive choice indicative of inventive step. Apparently, nothing would have prevented the appellant from starting with the cDNA library from testis tissue as this was how the cloning was done in post-published document (21). Furthermore, the choice of testis tissue does not necessarily imply that the cloning could not have been achieved with a reasonable expectation of success starting from human prostate tissue which was disclosed by Prof. J-A. Gustafsson during his presentation (cf. document (9)) as containing the ERß molecule.

31. Appellant I pointed to the fact that earlier experiments failed to isolate rat ERß DNA from brain tissue (cf. prior art document (6)). Of course, this is not necessarily indicative that inventive step would be needed to isolate human ERß DNA from testis tissue.

32. To summarize, the person skilled in the art knew from the presentation by Prof. J-A. Gustafsson (cf. document (9)) that a human analog to rat ERß existed and the possibility of cloning human ERß DNA had already been envisaged in the art. He/she also knew that rat ERß protein was very much identical to the ERalpha prototype of the family of hormone receptor in the DNA binding domain, which suggested that human ERß might have the same property. This knowledge made it obvious to start the cloning of human ERß DNA with primers originating from conserved sequences in the DNA encoding the DNA binding site. No specific difficulties were encountered when cloning, the solving of which might have warranted an acknowledgement of inventive step. None of the post-published information provides any evidence that the success in cloning was due to the specific choice of a cDNA library from testis tissue.

33. For these reasons, the subject-matter of claim 1 which relates to molecules having homology to human ERß in the DNA- and the ligand-binding domains does not fulfil the requirements of Article 56 EPC.

34. In the course of the written and oral proceedings, further objections were raised by Appellants II and III against the patentability of other claims. These need not be reviewed as a decision could be reached on the basis of claim 1 alone.