T 0018/08 (Device for drug delivery/BOSTON SCIENTIFIC) 17-08-2010

Reasons for the decision

1. The appeal is admissible.

2. Admissibility of auxiliary request 1

The amendments in this request were occasioned by the respondent's and the board's arguments during the oral proceedings.

In addition, the independent claim of this request is merely a combination of dependent claims from the application as originally filed, which have already been discussed in the proceedings before the opposition division (see decision of the opposition division, page 3, first paragraph under point 2.2 and patentees' reply to the notice of opposition, dated 3 November 2006, page 2, last but one paragraph). Thus, the amendments are clear-cut and bona fide attempts to answer the arguments brought forward during the oral proceedings.

The request is therefore admitted into the proceedings under Article 13(1) of the Rules of Procedure of the Boards of Appeal (RPBA).

3. Article 123(2) EPC; main request

3.1 The wording of claim 1 of the main request differs from claim 1 as granted in that the words "substantially" before "saturated solution with a concentration and …" and "of" in the term "limit of solubility" are omitted.

3.2 The subject-matter of claim 1 of the main request, however, cannot be derived from original claim 30 as alleged by the appellants.

Original claim 30 relates to

"a system … comprising a medical device that delivers the therapeutic agent at a pressure of from about 0 to about 5 atmospheres …".

The pressure-related feature contained in original claim 30 at least means that the system must be suitable for administration of the therapeutic agent in the defined range of pressure. Deleting this feature amounts to adding subject-matter to this claim since the restriction inferred to it by characterising its suitability ceases to apply.

3.3 As regards a disclosure without pressure-related features, it is to be noted that the subject-matter of claim 1 of the main request relates to three different ways of associating a substantially saturated solution of a therapeutic agent with an expandable catheter as the claimed device:

"… a therapeutic agent

- which is incorporated into the expandable catheter

- or coated onto the surface of the expandable catheter per se

- or as part of a coating …"

The comprehensive explanation of the meaning of the term "associated with" in connection with the substantially saturated solution is to be found on page 5 of the description as originally filed, lines 24 to 33:

"The substantially saturated solution is associated with the medical device in that the therapeutic agent

- is held in a cavity(ies) of the device, such as in an infusion style catheter such as a channel balloon catheter;

- or the therapeutic agent is coated onto the surface of the device as a coating per se

- or as part of a coating;

- or the substantially saturated solution is held within or passes through the medical device, such as in a needle injection catheter." (letters in bold by the board)

If the alternative "the substantially saturated solution is held within … the medical device" is disregarded - as was done during the proceedings till now and is continued in order to avoid further complications in the case - this comprehensive explanation contains four different ways in which a substantially saturated solution of a therapeutic agent may be associated with medical devices. The kind of devices is illustrated in the form of examples presented under the wording "such as".

"Such as" in this presentation of examples means that the forms of "association" described are not restricted to these examples, for instance the way of association mentioned under the forth bullet-point "… passes through the medical device" may relate to a "needle injection catheter" but can also relate to any other suitable catheter. Therefore, the "passes through …" way of association does not necessarily qualify as inapplicable if the device is restricted to expandable catheters and a needle injection catheter is not an expandable catheter.

Consequently, the mentioning of the three ways of association with an expandable catheter as contained in the current claim 1 of the main request, with respect to the comprehensive explanation on page 5 of the description as originally filed, lines 24 to 33, is an arbitrary choice out of a list of possibilities.

As far as the restriction of the device to an expandable catheter itself is concerned, there are several lists of "suitable catheter[s], such as, for example" to be "used with the present invention" (see description, page 6, lines 8 and 9) or as "medical devices within the scope of the present invention" (see page 5, line 36 to page 6, line 1). The most general one of these lists on top of page 6 of the description as originally filed is introduced by "The present invention is described herein with specific reference to an expandable catheter as the medical device. Other medical devices …" (see page 5, lines 34 to 36). This introduction, however, means nothing other than that the expandable catheter is chosen in order to be used to specifically describe features of the "invention". It does not confer any state of preferred embodiment on the expandable catheter, be it literally or by consistent interpretation of the phrase.

Thus, also the restriction of the device to the expandable catheter amounts to an arbitrary choice of this specified embodiment from the teaching of the application as originally filed.

3.4 In addition, in no other part of the description is the totality of the three ways of association, together or as an agglomeration of the single ones, mentioned in context with the substantially saturated solution of the therapeutic agent and/or an expandable catheter. Either the description refers to the "expandable portion of a catheter", which is not a synonymous term for "expandable catheter", or there is no context with a substantially saturated solution, or both of these deficiencies apply. This relates in particular to page 6, lines 8 to 21 and page 8, lines 24 to 31, parts of the application as originally filed on which the appellants relied as source of original disclosure.

3.5 Consequently, directing the subject-matter of claim 1 of the main request to its combination of three ways of association with an expandable catheter as the device results in claiming embodiments of the teaching of the application as originally filed that are not individualised there and therefore appear in sum as an arbitrary choice. The requirements of Article 123(2) EPC therefore are not met.

3.6 Under these circumstances, the additional arguments of the appellants with respect to Article 123(2) EPC cannot succeed.

A majority or all examples in an application as originally filed having one feature in common does not limit the subject-matter of a claim to this common feature and therefore is no valid basis for a corresponding restriction. Thus, all the examples being directed to expandable catheters, even if undisputed, cannot represent the source of original disclosure of expandable catheters being the only device referred to in claim 1 of the main request.

4. Auxiliary request 1

4.1 Article 123(2) and (3) EPC

4.1.1 Claim 1 of auxiliary request 1 can be derived from claims 34, 33 and 30 in combination with page 5, lines 15 to 21 of the application as originally filed.

It is restricted to the way of association of the substantially saturated solution (as explained on page 5, lines 15 to 21 of the original description and set out in claim 1 as granted) with the expandable catheter (now in terms of a "catheter including an expandable portion") that corresponds to the wording

"a therapeutic agent … coated onto the surface of the expandable catheter … as part of a coating".

Since the term "surface" in claim 1 as granted is not further specified (e.g. as inner or outer surface or something similar) the meaning of the wording "said expandable portion being coated with a polymer coating" without mentioning the word "surface" is regarded as not exceeding the teaching of claim 1 as granted.

4.1.2 Thus, claim 1 of auxiliary request 1 meets the requirements of Article 123(2) and (3) EPC.

4.2 Auxiliary request 1; Article 83 EPC 1973

4.2.1 Auxiliary request 1 refers to a system for localized delivery of a therapeutic agent comprising a catheter and a substantially saturated solution of said therapeutic agent in a solvent.

The substantially saturated solution of said therapeutic agent in the solvent is characterised by a minimum value above which the concentration of the therapeutic agent in said solvent is to be found.

By this means, the parameter "concentration … of at least 75% of the limit solubility …" being a concentration in relation to the limit solubility (relative concentration) is considered to deliver information necessary to describe the claimed system.

Consequently, in order to carry out the invention characterised by that parameter, the skilled person must be able to measure in a very clear and complete way the relative concentration of therapeutic agent in the substantially saturated solution contained in any one of the systems he tries to produce according to all the features set out in claim 1 of auxiliary request 1 (reproducible measurement on the same sample with the same apparatus under the same conditions) and he must be sure that the measured value is the same as the appellants obtained for their substantially saturated solution contained in their corresponding device before filing their application (repeatable measurement on another sample of the same kind with another apparatus, but under the same conditions).

4.2.2 In order to measure the relative concentration, the reference concentration "limit solubility" must be known.

"Limit solubility", however, or "limit of solubility" (as is used in claim 1 as granted) are not common terms known in the world of the person skilled in the art. In addition, these terms are also not defined in the description as originally filed.

4.2.3 Under these circumstances it does not matter that claim 1 as granted as well as claims 1 of the current auxiliary requests 4 and 5 relate to "limit of solubility" while claims 1 of the current main request and the auxiliary requests 1, 2 and 3 contain the term "limit solubility". Each of the terms "limit of solubility" and "limit solubility" is nowhere defined and since in the description as originally filed "limit of solubility" is used in order to describe the term "substantially saturated solution" (see page 5, lines 15 to 21) and is unequivocally meant as source of disclosure for claim 1 of auxiliary requests 1, 2 and 3 too, the present decision generally uses "limit of solubility" below.

4.2.4 Since there is no definition of the term "limit of solubility" and what the skilled person would do to give it any meaning is open, the person trying to carry out the invention never knows whether a device produced by him would meet the features of claim 1 as filed under auxiliary request 1, because he can never be sure whether another skilled person would give it another meaning transferring his device from being covered by the claim to not being covered. Thus, he is not in a position to carry out the invention as described by this claim.

4.2.5 In the circumstances of the case, the arguments of the appellants with respect to Article 83 EPC 1973 cannot succeed:

The appellants' arguments result in the opinion that the person skilled in the art would automatically read "limit of solubility" as synonymous with "saturation" of a solution and refer to experiments to determine the maximum concentration of therapeutic agent in a pure solvent using standard conditions of temperature, pressure etc. and keeping pure agent and solution under equilibrium.

However, since the term is not generally defined, the skilled person could equally read "limit of solubility" as an invitation to exceed these equilibrium conditions in some way, for instance by trying to produce oversaturated solutions stable under particular conditions and taking their concentration as reference for "limit of solubility".

On the other hand, even if committing himself to equilibrium conditions the person skilled in the art could apply "limit of solubility" either with respect to the equilibrium concentration at room temperature or at the temperature at which the system was finally to be used, 37ºC.

In any case, a system produced under one particular definition of "limit of solubility" could fall under the scope of the claim and equally be out of this scope under another definition.

Thus the skilled person never knows whether he is staying within the scope of the claim or not and therefore cannot purposively carry out the invention.

5. Auxiliary requests 2 to 5; Article 83 EPC 1973

It is clear from the argumentation under point 4.2 of this decision that the use of the undefined term "limit of solubility" results in a teaching of claim 1 that cannot be carried out in the sense of Article 83 EPC 1973.

In claims 1 of auxiliary requests 2 to 5 the term "limit of solubility" still exists and it is used in the same way as in claim 1 of auxiliary request 1. Therefore, these auxiliary requests 2 to 5 do not meet the provisions of Article 83 EPC 1973 either.