T 1823/11 - Sufficiency of disclosure - how to do it right.

Keypoint

• The Board shows how to do the assessment of sufficient of disclosure of a second medical use claim.
• A claim for the use of phaseolamin as an anticaries agent can be novel and inventive over a document describing use of an plant extract, which inherently contains the protein, for inhibiting the adherence of plaque-producing bacteria to the teeth. In particular since another compound was believed to be the active ingredient.

T 1823/11

Dated 20 May 2015, publication date 29.05.2015 - for the decision, click here.

Reasons for the Decision

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2. Article 83 EPC

2.1 In its decision to refuse the application for non-compliance with the requirements of Article 83 EPC, the examining division pointed out two deficiencies, namely the absence of indications as to the preparation of phaseolamin and the absence of any information as to the pH conditions.

2.2 With regard to the absence of information as to the preparation of phaseolamin, the appellant explained during the examination proceedings that this protein was well known and even commercially available at the date of filing (letter of 14 December 2010).

Indeed documents D2 (see page 4, lines 8 to 25) and D3 (see example 22) indicate that phaseolamin was known before the priority date of the application. This is also confirmed in the post-published document D7 in which the protein phaseolamin is described by reference to an article published in 1992 (page 1, lines 16 to 28).

Document D2 is also evidence for the appellant's statement that phaseolamin was commercially available. This document, published nearly two years before the priority date of the present application, indicates that phaseolamin is available in two grades of purity and provides the name of a commercial source of the product (page 4, lines 18-21). From document D2 the skilled person would also derive the information that phaseolamin is a glycoprotein which inhibits alpha-amylase and can be extracted from Phaseolus vulgaris (page 4, lines 8 to 17). Detailed information concerning the isolation from Phaseolus vulgaris of proteins inhibiting alpha-amylase are furthermore disclosed in document D6 (page 32, "Material and methods").

2.3 From the above the Board concludes that phaseolamin was a protein sufficiently known at the filing date of the application. Thus, even in the absence of any instruction with regard to its preparation, the skilled person would have easily retrieved information with regard to its commercial availability or with regard to the methods for extracting it from Phaseolus vulgaris.

2.4 The second deficiency considered by the examining division, in relation to the assessment of sufficiency of disclosure, concerns the absence of information as to the pH of phaseolamin.

The examining division did not explain why such information would be essential to the skilled person in order to carry out the invention. In this respect the Board notes that in the submissions made during the first-instance proceedings (letter of 14 December 2010), the appellant explained that caries is caused by acid-producing bacteria which lower the pH of saliva. Phaseolamin, which exerts its activity at acidic pH, would therefore be inevitably activated by the pathogenic mechanism underlying caries formation.

The acidogenic nature of the bacteria causing caries is indeed confirmed by D5 (column 1, lines 12 to 32), while from D6 (see Figure 4) it can be seen that the alpha-amylase inhibitor extracted from Phaseolus vulgaris exerts its activity in acidic conditions (see also point 2.5 below). These documents support the arguments of the appellant and justify the absence of information in the application in relation to the pH at which phaseolamin is to be used.

2.5 Independently from the considerations made above, in the Board's opinion, testing phaseolamin under different conditions of acidity in order to verify in which range of pH it maintains a sufficient enzymatic activity, is an activity that would not require any undue effort. In this respect it is observed that only pH values compatible with an oral use would need to be investigated.

Moreover, documents D6 provides extensive information concerning the characterization and functional properties of the alpha-amylase inhibitor extracted from Phaseolus vulgaris. D6 indicates inter alia that the enzyme is active in a range of pH comprised between 4 and 5.5 and shows a maximum of activity at pH 4.5 (see abstract and Figure figure 4).

2.6 In the light of the considerations made in points 2.4 and 2.5 above, the Board concludes that the absence of information with regard to the pH of phaseolamin would not affect the capacity of the skilled person to carry out the invention.

2.7 Hence, the reasons adduced by the examining division to conclude that the requirements of Article 83 EPC were not met, are not tenable.

3. Remittal of the case to the examining division (Article 111(1) EPC)

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Thus, the Board concludes that in the circumstances of the present case, it is necessary to remit the case to the first instance for further prosecution (Article 111(1) EPC).

3.2 The following observations need to be taken into consideration for the further prosecution of the examination.

3.2.1 In the Board's opinion to complete the assessment of the requirement of sufficiency of disclosure it is necessary in the present case to investigate also a further relevant issue.

Claim 1 is drafted as a purpose-limited product claim in accordance to Article 54(5) EPC. Hence, the technical effect of phaseolamin of being useful as an anticaries agent, is expressed in the claim.

When the technical effect is expressed in the claim, the issue as to whether this effect is indeed achieved over the whole scope of the claim is a question of sufficiency of disclosure (G0001/03, OJ 2004, 413, Reasons 2.5.2). This general approach applies in particular to claims including a therapeutic effect as a feature of the claim, such as purpose-limited product claims in accordance with Article 54(4) and 54(5) EPC or claims drafted in accordance with the "Swiss-type" format (see for instance: T906/10, Reasons 23; T1616/09, Reasons 6.2; T1869/11, Reasons 3.2.1).

Thus, in order to establish whether the requirement of sufficiency of disclosure is met it needs to be assessed whether the application discloses the potential suitability of phaseolamin to act as an anticaries agent or whether this information can be derived from the prior art.

3.2.2 As discussed above (see points 2.4 to 2.6), the concerns expressed by the examining division related to the question of whether the pH has an effect on the enzymatic activity of phaseolamin. However, the examining division has not addressed in its decision the issue as to whether phaseolamin is potentially suitable to be used as an anticaries agent, nor does it appear that this question has been treated in any of the communications. Therefore, this issue will have to be considered by the examining division in the context of the assessment of the requirement of sufficiency of disclosure.

3.2.3 With regard to the requirement of inventive step, the examining division has expressed the opinion that the claims would not be inventive in view of the teaching of document D5. The opinion is given as an obiter dictum, in a paragraph with the title "Additional remarks".

In that respect, the Board wishes to make some comments in relation to the content of D5 since this document was initially considered by the examining division to affect the novelty of the claims (see III above), and in the "Additional remarks" it was considered to render them obvious.

3.2.4 Document D5 relates to compositions containing one or more lectins useful for inhibiting the adherence of plaque-producing bacteria to the teeth (see column 1, lines 6 to 11 and 46 to 57). The lectins are derived from the seeds of various plants including Phaseolus vulgaris (column 2, line 65 to column 3, line 6 and claim 1). Document D5 does not mention anywhere that the extracts of Phaseolus vulgaris or of any other seed may contain also phaseolamin. This protein is actually never mentioned in D5. Moreover, the document clearly identifies lectin as the active ingredient of the compositions (column 2, line 65).

Document D5 therefore does not disclose, even implicitly, the use of phaseolamin as an anticaries agent.

3.2.5 The examining division appears to have considered that an extract of Phaseolus vulgaris would also contain phaseolamin and that the use of this extract in accordance with the teaching of D5 would result in the use of phaseolamin in the treatment or prevention of caries.

Even assuming that the examining division was correct in concluding that an extract of Phaseolus vulgaris would also contain phaseolamin, none the less document D5 does not disclose the use of this protein in the treatment of caries. In this respect the Board underlines that in determining what a prior art document discloses the question to be decided is what has been made available to the public, rather that what may be have been "inherent" in what has been made available (G6/88, OJ 1990, 114, Reasons 8 to 8.2). Attaining an anticaries effect with phaseolamin is technical information which is not made available by D5, irrespective of any consideration concerning the pH. This aspect should be considered when assessing the patentability of the claims in view of this document.

Order

For these reasons it is decided that:

1. The decision under appeal is set aside.

2. The case is remitted to the department of first instance for further prosecution.