Saturday, 11 December 2010

T 1293/06 – What’s Hidden Won’t Help

Independent claim 1 as granted read as follows: 

“A pharmaceutical composition comprising ceftiofur hydrochloride, a biocompatible oil, and 0.5 to 200 mg/ml water.”

The Opposition Division (OD) revoked the patent.

Claim 1 of the main request before the Board differed from claim 1 as granted, in particular with regard to the definition of the range of water being present. It was worded as follows:

“A pharmaceutical composition comprising ceftiofur hydrochloride, a biocompatible oil, and 2.5 to 22.0 mg of water/ml of composition.”

The Board found this claim to be novel and then examined its compliance with A 56.

The opponent presented experiments showing that there was no amelioration of the physical stability of the claimed products and a worsening of the chemical stability in the time of storage, such that the problem of improvement was not solved over the claimed range of water content.

The patent proprietor dismissed these experiments by pointing out that results at odds with its own experiments could find their explanation solely in steps used during the production procedure by the respondent, that were not “perfect” in the art of production of dispersions. In particular the phenomenon of caking would have been avoided by the skilled person in routinely optimising the order of the preparation, stirring and dissolution steps.

Here is the verdict of the Board:

[4.1] Document D11 represents the closest state of the art.

[4.2] The definition of the technical problem underlying the patent in suit relies on the claimed effect, i.e. the improvement of the physical stability of the pharmaceutical formulation in the form of resuspendability while not abandoning the usefulness of the preparation in the pharmaceutical field in the form of the chemical stability of ceftiofur hydrochloride as far as required by the authorities, meaning usually less than 10% decrease in potency during shelf life […]. In order to establish a valid basis for the assessment of inventive step, this effect necessarily must be caused by the sole feature in the claim differing from the state of the art, i.e. the amount of water incorporated in the pharmaceutical composition of the claimed invention (see point 3.1 of this decision).

[4.2.1] Since claim 1 of the main request concerns a product per se, the claimed subject-matter is independent of the manner of its production. Vice versa, with respect to the question of patentability based on the claimed effect, this effect also has to be achievable independently, i.e. the product as claimed has to exhibit this effect no matter how it is produced, as far as it is “prepared by any method known in the art for the preparation of injectable suspensions”, as inherently confirmed by the [patent proprietor] via the patent in suit […].

[4.2.2] The [opponent], in the production of its samples, undoubtedly used another process of preparation than the [patent proprietor]. As a reaction to the questions raised by the [patent proprietor …], the [opponent] explained its process of production during the oral proceedings. The [patent proprietor] at least in part commented on differing steps as used in its own process of preparation.

On this basis, the board has no reason to doubt the [opponent’s] professional conduct of its process of preparing the samples of documents D12 and D20.

Consequently, the board finds that the claimed effect of better resuspendability could not be affirmed in the case of application of the process of production as conducted by the [opponent], who is a skilled person applying his knowledge with usual care.

As set out in documents D12 and D20, two lots falling under the scope of the claim were assessed: lot B-1 (11,1 mg of water per ml of composition) exhibiting at least no better resuspendability than lot A (2.3 mg/ml) after 15 days and 3 months, and lot B-2 (21.0 mg/ml) exhibiting an even worse one.

Lot A was produced according to document D11 as closest prior art, since the components ceftiofur hydrochloride and biocompatible oil were used as mentioned there without adding water […]. According to claim 1 of the main request, with ceftiofur hydrochloride and biocompatible oil as the only mandatory components in the claimed composition, there was no addition of lecithin and sorbitan monooleate.

[4.2.3] Consequently, the effect of better resuspendability is not exclusively caused by the choice of the claimed amount of water alone, but at least also or even only by undefined other effects, e.g. another “method known in the art for the preparation of injectable suspensions”. Therefore, this effect cannot be acknowledged as a basis for the problem to be solved when assessing inventive step.

[4.2.4] Thus, the problem underlying the invention, i.e. the improvement of the physical stability of the pharmaceutical composition, is not successfully solved by the provision of a pharmaceutical composition characterised by the features of claim 1 of the main request, and has therefore to be reformulated in a less ambitious way.

It is therefore only to be seen in providing a further pharmaceutical composition containing ceftiofur hydrochloride.

[4.3] According to claim 1 of the main request, one solution to this problem is the adjustment of the water content in a pharmaceutical composition comprising ceftiofur hydrochloride and a biocompatible oil to 2.5 to 22.0 mg of water/ml of composition.

[4.4] The board is convinced that this problem has been solved.

[4.5] In [… D2], however, it is disclosed that ceftiofur hydrochloride based on this process of preparation may contain 0.5% to 7% of water or other solvents, usually 1% to 3%, meaning in a 1 ml sample according to example 7 of document D11 a content of 100 mg of ceftiofur hydrochloride and as the upper limit 7 mg or 3 mg of water.

Accordingly, the teaching of the application in suit only puts into practice what is already known to the skilled person from document D11 together with document D2; at most, the teaching of the patent in suit presents itself as an arbitrary modification of the preparation of the state of the art (document D11) with respect to its water content, the variations of which are known from document D2.

[4.6] Consequently, the board concludes that the subject-matter of claim 1 of the main request does not involve an inventive step (A 56).

Should you wish to read the whole decision, just click here.

If you want to have a look at the file wrapper, click here.