Thursday, 29 July 2010

T 788/06 – Double Agents Are Troublesome

Claim 1 of the main request read:

A pharmaceutical composition in the form of a tablet, wherein said composition comprises, based on weight:
(a) from 20 to 70% irbesartan or a pharmaceutically acceptable salt thereof,
(b) from 1 to 70% diluent,
(c) from 2 to 20% binder,
(d) from 1 to 10% disintegrant,
(e) from 0.1% to 5% antiadherent,
(f) from 0.2 to 5% lubricant,
(g) from 0.2 to 6% surfactant,
wherein the surfactant is a poloxamer, wherein the tablet formed from said composition has a dissolution performance such that 80% or greater of the irbesartan or salt thereof contained in said tablet dissolves within 30 minutes.

[3.1] A 100(b) defines lack of the invention to be disclosed in a manner sufficiently clear and complete for it to be carried out by a person skilled in the art as a ground for opposition. One of the provisions for the resulting requirements to be fulfilled is that the skilled person must be in a position to recognise whether or not the result of one of his reproductive experiments corresponds to the teaching of the patent in suit.

[3.2] In the present case, claim 1 in all the requests seeks protection for a pharmaceutical composition as a product per se.

The pharmaceutical composition is characterised by %ranges for the ingredients selected from at least five groups of substances:

(b) diluents,
(c) binders,
(d) disintegrants,
(e) antiadherents,
(f) lubricants,

The %ranges are essential technical features in the corresponding claims since they characterise the limits within which the sums of percentages of different ingredients (substances) selected from any of the groups must remain.

In order to enable the skilled person to produce an embodiment as subject-matter covered by such a claim, the groups and the %ranges for them in the product as claimed must be defined unequivocally.

[3.3] The groups from which the ingredients of a pharmaceutical composition are to be selected are characterised in terms of the functions that any ingredient should perform in the pharmaceutical composition and not in structural terms of chemical substances (main request and auxiliary request 1) or in structurally defined groups of substances with their function as additional remarks (auxiliary requests 2 and 3).

[3.3.1] In the description of the patent, it is set out that a single compound may perform two or more functions […].

In particular, from claim 4 of the main request and auxiliary request 1 and claim 1 of auxiliary requests 2 and 3 follows that alginic acid, sodium alginate, carboxymethylcellulose sodium, starch and pregelatinized starch may be binder or disintegrant.

Microcrystalline cellulose may be diluent or disintegrant.

Talc may be antiadherent or lubricant.

[3.3.2] If, under these circumstances, for instance, a pharmaceutical composition
− contains binder in an amount at the upper limit claimed for binder (20%) and
− the binder already contains starch
− and now a certain amount of additional starch is added,
there are two arbitrary ways of classifying this additional amount of starch:
− as a disintegrant or
− as further binder.

Depending on the outcome of that choice, the pharmaceutical composition resulting from the addition of starch is or is not contained in the claimed subject-matter.

If the additional starch is classified as a disintegrant and its percentage remains beneath the upper limit of the %range claimed for disintegrant materials, the pharmaceutical composition resulting from the addition must be regarded as subject-matter as claimed.

If, however, the additional starch is classified as binder, the claimed range of binder is exceeded and the resultant pharmaceutical composition constitutes subject-matter which is beyond the limits of the claim.

Thus, two totally different conclusions can be reached in answering the question whether the pharmaceutical composition is subject-matter as claimed or not, despite the material having the identical composition. These two conclusions, one being the complete opposite of the other, are simply the result of the fact that some of the ingredients of the pharmaceutical composition can be classified arbitrarily.

[3.3.3] The same effect is to be observed when the amount of ingredients of the different groups is changed slightly compared with the example mentioned above; for instance, it is not at all necessary to start with binder in an amount exactly equal to the upper limit as claimed. This special case has only been taken above for convenience and ease of explanation of the facts and effects.

[3.3.4] Thus, in quite a lot of cases, the skilled person trying to carry out the teaching of the claims, i.e. the claimed invention, does not know whether or not he will get a pharmaceutical composition as claimed, which amounts to the problem that he cannot carry out the teaching at all.

[3.3.5] The question of starch belonging to both the binder and the disintegrant groups applies to all of the main request and auxiliary requests 1 to 3. The same problem arises with the other functionally defined groups of ingredients as defined above under point [3.3.1] of this decision.

[3.4] To summarise, for the skilled person, with respect to the main request and auxiliary requests 1 to 3, there is no unequivocal definition in the patent in suit of the %ranges for binder and disintegrant, for diluent or disintegrant, or for antiadherent or lubricant in the pharmaceutical composition as claimed. Consequently, this feature leaves the actual subject-matter covered by the claim in doubt.

Therefore, in the board’s judgement, claim 4 according to the main request and auxiliary request 1 and claim 1 of the auxiliary requests 2 and 3 fail to meet the requirement of sufficient disclosure imposed by the ground for opposition under A 100(b). […]

[4] In addition, the further argument of the respondent cannot succeed: The skilled person may be able to recognise the primary function of an ingredient, but only in general terms when looking at a particular composition. A sound, clearly distinguishing correlation will not be possible for each and every percentage being claimed and for each and every environment as given by the percentages of the other ingredients. Moreover, even the wording “primary function” already indicates that there may be a doubt as to whether or not the secondary function would have to be taken into account or even if it would prevail in a particular case. Thus, the teaching with respect to the compositions as claimed supplies no clear and complete basis for carrying it out.

If you wish to download the whole decision, just click here.