T 0234/07 (Back-staining/NOVOZYMES) 24-04-2009

1. Main request

1.1 In the oral proceedings the Proprietor confirmed that the feature of Claim 1 "wherein each cellulase displays at least 30% of its maximum activity at pH 7" is a restrictive parameter. Thus, this feature has to be used by the person skilled in the art to select cellulases suitable for the claimed method.

1.2 Some explicit examples of suitable enzymes are given in the description of the patent-in-suit, however, the wording of Claim 1 covers many more enzymes.

It is established case law that the disclosure of an invention is only sufficient if it enables the skilled person to obtain substantially all embodiments falling within the ambit of a claim (cf. T 0409/91 EPO OJ 1994 653, point 3.5 of the reasons), i.e. also the cellulase enzymes according to the wording of the claims which are not explicitly disclosed.

1.3 In relation thereto the Proprietor referred to the assay according to paragraph 47 of the patent as granted. This passage reads as follows:

"The cellulase endo-activity is determined by the reduction of viscosity of CMC (carboxy-methyl cellulose) in a vibration viscosimeter. 1 ECU (endo-cellulase unit) is the amount of activity which causes a 10-fold reduction of viscosity when incubated with 1 ml of a solution of 34.0 g/L of CMC (trade name Aqualon 7LFD) in 0.1 M phosphate buffer (pH 7.5), 40ºC for 30 minutes."

1.4 When analysing the cited passage carefully, it becomes apparent that the alleged "assay" does not give any instructions on how to perform the determination of the cellulase activity.

The first sentence simply states that CMC is used as a substrate and that the test is carried out in a vibration viscosimeter. No details are given as to temperature, time, buffer or concentrations.

The second sentence relates to the definition of a specific unit, the ECU. Although this definition includes more information concerning the process parameters, it has to be emphasized that the passage neither is to be seen as instructions relating to a working method, nor does it give any details how to carry out the tests at conditions other than the ones specified, e.g. at different pHs.

1.5 Also the remaining disclosure of the patent does not show how to identify enzymes meeting the criterion concerning maximum cellulase activity.

1.6 Even when arguing, that the skilled person would transform the information given in the ECU definition into a working method to carry out tests at different pHs, there would still not be sufficiency of disclosure:

Paragraph 47 refers to cellulase endo-activity and endo-cellulase units. The wording of Claims 1 is not restricted to such endo-cellulases. This has been explicitly confirmed by the Proprietor during the oral proceedings.

Thus, even if the ECU definition were considered to be suitable as a working method for determining the activity of endo-cellulases at different pHs, there would still not be any teaching on how to determine suitable exo-cellulases.

1.7 Furthermore, the argumentation that the problems encountered when putting the invention into practice relate to a lack of clarity rather than insufficiency of disclosure can also not be followed. The passage of Claim 1 relating to maximum activity of the cellulases is not ambiguous or open to interpretation. Simply no information is given in the patent on how to identify enzymes meeting this requirement.

1.8 In addition, Proprietor's arguments concerning lack of evidence that proper identification of cellulases from Bacillus/Humicola is not possible, is also not found by the Board to be valid. As stated above and confirmed by the Proprietor, also exo-cellulases are covered by Claim 1. The patent-in-suit does not contain any teaching how to identify such exo-cellulases. In this respect the Board does not regard any further proof by the Opponent to be necessary.

1.9 Consequently, the main request lacks sufficiency of disclosure (Article 83 EPC).

2. First auxiliary request

2.1 Claim 1 of the first auxiliary request differs from Claim 1 of the main request by the additional feature "wherein the first component is at a concentration of 10-1000 ECU/l".

2.2 Since the first auxiliary request was filed during the oral proceedings, i.e. at a very late moment of the procedure (as objected to by the Opponent), included features from the description and is not suitable to overcome the problems with regard to sufficiency of disclosure as discussed above, the Board decided in accordance with Art. 13(1) RPBA (EPO OJ 11/2007 536), that the first auxiliary request is not admissible.

3. Second to seventh auxiliary request

3.1 Each of these auxiliary requests contains in Claim 1 at least one reference to a cellulase having an abrading activity or a reference to Bacillus or Humicola.

3.2 Since all of these definitions encompass a large number of specific strains producing different types of enzymes, the problem on how to identify suitable cellulases displaying at least 30% of their maximum activity at pH 7, as discussed above, remains.

3.3 Thus, for the same reasons as for the main request the second to the seventh auxiliary request are not considered to meet the requirement of Article 83 EPC.

4. Eighth auxiliary request

4.1 The subject-matter of the eighth auxiliary request differs from the previous requests in that two very specific enzymes from Humicola insolens DSM 1800, namely EG I and EG V, are used.

4.2 Sufficiency of disclosure

Although the feature relating to the enzymes' activity at pH 7 is still part of Claim 1, the person skilled in the art does not need to carry out tests to find suitable enzymes, because only two specific enzymes are used in the method according to Claim 1. Thus, the requirement concerning sufficiency of disclosure is considered to be met.

The Opponent shared this point of view in the oral proceedings.

4.3 Clarity

The only objection raised by the Opponent concerning the eighth auxiliary request is with regard to clarity of the term "essentially" in Claim 1. However, the term was already present in dependent Claim 11 as granted.

According to established jurisprudence of the Boards of Appeal, features being present in the claims as granted are usually not re-examined in appeal phase for lack of clarity.

Opponent's argumentation that it has only become apparent after the combination of Claims 1 and 11 as granted, that the term "essentially" lacks clarity, cannot be followed.

Although only present in a dependent claim, examination of the meaning of this term was part of the tasks of the Examining Division before granting the patent. The meaning of this feature did not change at a later stage of the procedure, when it was incorporated into the independent claim 1. Consequently there is no need to re-examine the question of clarity.

The requirements of Article 84 EPC for the eighth auxiliary request are considered to be met.

4.4 The Board does not have any reason to object the requirement under Art. 123(2) EPC, novelty or inventive step of the claimed method. Since the Opponent did not contest this (see point VI), there is no reason to give a detailed reasoning why the claimed method is novel over the cited prior art and not obviously derivable or why the requirement of Art. 123(2) EPC is met.