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T 1989/19 – Acknowledgement of IS on the basis of post published experimental data under G 2/21 - Is it always correct?

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The patent relates to micronised crystalline tiotropium bromide. The corresponding application is a divisional of EP 03708206/EP 1 487 832.

Brief outline of the case

The four opponents have appealed the rejection of their oppositions. Eventually one opponent was left.

The board confirmed the rejection of the remaining opposition.

The case is interesting since the board decided to consider a technical effect shown in post-published documents in the light of decision G 2/21.

The opponent’s point of view with respect to IS

The claimed crystalline micronisate of tiotropium bromide differed from that of D9=CPA in that its water content ranged from 1% to 4.0%.

The opponent argued, inter alia, that the experimental data in D23 and D65 were post-published and that the originally filed application contained no reference to the technical effect of improved storage stability shown in D23 and D65. Therefore, this effect should not be taken into account when assessing IS.

The board’s decision on IS

The water content is the distinguishing feature compared to D9, and no water content is disclosed in D9.

The proprietor relies on the technical effect of improved storage stability demonstrated by means of D23 and D65. The assessment of whether this technical effect can be taken into account in the examination of inventive step has therefore be made from the perspective of a person skilled in the art using his general technical knowledge and of the application as originally filed.

From point 93 of the reasons in G 2/21, the board concluded that for a technical effect to be recognised in the context of the assessment of inventive step, it is not a prerequisite that this claimed effect must be expressly mentioned in the application as originally filed or proven therein.

Rather, a technical effect proven by post-published evidence can be recognised within the meaning of point 2 of the decision formula of G 2/21 if it can be derived as encompassed by the technical teaching of the application as originally filed and as embodied in the same invention as originally disclosed. This in turn means that, with regard to this technical effect, the nature of the claimed invention is not changed with respect to the originally disclosed invention.

The application as originally filed focuses on the use of the claimed micronisates as inhalation powders and teaches that a certain particle size range is required for administration by inhalation. Since a certain time necessarily elapses between the preparation of a medicament and its administration, it can be inferred from the application as originally filed that particle size stability (corresponding to the storage stability demonstrated in D23 and D65) is an essential requirement for the administration of the medicament as claimed in the application.

Moreover, as submitted by the proprietor at the OP, prior to the priority date of the application, it was common knowledge of the skilled person that the stability of the particle size is of crucial importance for the administration of a pharmaceutical by inhalation.

Based on this technical knowledge concerning the necessary particle size/particle size distribution in the use of inhalation powders for medical administration, the skilled person would recognise, on the basis of the originally filed version of the application, that the tiotropium bromide also has adequate particle size stability due to the disclosed particle sizes and its intended use. This stability corresponds to the technical effect of storage stability referred to by the proprietor for the acknowledging IS. The skilled person would therefore directly infer the storage stability of this product from the use of the claimed micronisate as an inhalation product as described in the application as originally filed.

In the board’s view, once the above-mentioned criterion of the derivability of a technical effect is fulfilled, this applies equally to the improvement of this effect. Therefore, if a certain technical effect, such as storage stability in the present case, is derivable for the skilled person within the meaning of point 2 of G 2/21, from the originally filed application, its improvement is also to be regarded as implicitly derivable.

Thus, the fact that the technical effect relied on by the proprietor consists in a storage stability that is improved over the closest prior art does not prevent it from being taken into account in the light of decision G 2/21.

Consequently, the technical effect of the improved storage stability shown in the post-published documents D23 and D65 does not change the nature of the claimed invention.

Based on the technical effect of improved storage stability, the objective technical problem is to provide a tiotropium inhalation powder with improved storage stability.

Neither in D9 nor in the further prior art cited by the opponent is there any indication that this problem can be solved by the crystalline micronisate of claim 1. Nor has the opponent put forward any arguments to show that the claimed subject-matter would not involve an inventive step if the technical effect of improved storage stability were recognised and taken into account.


The present decision is to be seen in comparison with T 681/21, commented on this blog. In T 681/21, the board concluded that in the absence in the description as filed of the mention of a synergy effect, it is much more difficult to justify IS on a later alleged synergy effect.

The present decision goes a bit further than T 681/21. Whether it is reasonable to accept such later discovered effects in order to acknowledge IS is at least doubtful. In the case at the basis of G 2/21, at least some synergy was present, if not for the type of moths at stake.

The only stability mentioned in the application as filed is that a high stability of the active ingredient during the grinding process (micronisation) is an absolute necessity. Storage stability is not at all mentioned.

After all, for any medicament it appears trivial that storage stability has to be given if there is some time between its manufacture and its use. It appears difficult to acknowledge IS on the basis of such a trivial consideration. It is at best a bonus effect which should not be taken into account when assessing IS.

It is to be feared that G 2/21 has actually created a loophole by which proprietors can claim an effect, i.e. a contribution to the state of the art, which they never envisaged at the time of filing, or which has to be given in view of the use of the product.

Strong doubts are permitted that such a way to acknowledge the presence of IS at all correct. An applicant/proprietor should not be rewarded for something it has never conceived or which is actually trivial.

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6 replies on “T 1989/19 – Acknowledgement of IS on the basis of post published experimental data under G 2/21 – Is it always correct?”


I agree that doubts are permitted and justified, if not more than just that. The gist of G 2/21 does not seem to be followed by this T decision. If applying a “could-would” to the effect, the T decision’s reasoning seems rather a “could” than a “would”, and hence not the correct approach for inventive step, as G 2/21 provides essentially a “would” reasoning.

Avatar photoDaniel X. Thomassays:

@ Anonymous,

Thanks for your comment.

Your thoughts about the could/would are very interesting and I can agree with them.

It remains that the effect claimed in view of D9 has never been envisaged originally. This renders the application of G 2/21 problematic, as for any medicine, storage capability is an intrinsic and important factor.

Max Dreisays:

Daniel, I have some questions. I could answer them to some extent by reading various docs on the EPO file but it is more illuminating to ask you instead. I hope it will not be a waste of your time.

Did D9 disclose micronisate powder for inhalation or only powder for some other purpose? If the former, then its readers can assume that its powder already has a storage stability good enough for inhalation. I note that D23 and D35 evidence “improved” storage stability, but improved relative to what? D9 has no disclosure of water content so how do we know whether the storage stability of the claimed powder is superior to that of any of the powders disclosed in D9?

I can see that the skilled reader of the patent application as filed reads into the disclosure a level of storage stability adequate for an inhalation powder. Where I’m struggling is with the idea that the skilled reader derives from the application as filed an”improved” storage stability (or that anybody would need a storage stability that is more than adequate). To repeat: improved relative to what?

Avatar photoDaniel X. Thomassays:

Dear Max Drei,

Thanks for your comment/questions.

The answer to your first question is very clear: D9 disclose micronisate tiotropium bromide powder for treating inflammatory or obstructive airways diseases and not for some other purpose.

What the proprietor has argued is that his micronisate tiotropium bromide powder has allegedly a better storage capacity than that of D9 in which no water content has been defined.

It is well known that, as a powder, tiotropium bromide can easily clog. Stability of storage is thus an important aspect, be it in D9 and in the patent.

Defining the proper water content, is thus of utmost importance. I am therefore inclined to consider that determining the proper water content of the powder is to be carried out by routine experiments.

By alleging that the claimed tiotropium bromide has a better stability than that of D9, in which no water content is given, I am inclined to say the proprietor has compared apples with pears. The answer to your second question is thus also clear an alleged improvement over D9 is more than doubtful.

I would go one step further. In the patent, the proprietor has insisted on the stability of the tiotropium bromide during the micronisation. As the micronisate in D9 and in the patent are identical, to the water content, the process to micronisate the tiotropium bromide must at least be comparable. D9 is, alas, silent with respect to any process of manufacture.

I cannot say that the decision is incorrect, but a reasonable suspicion with the regards to the application of G 2/21 is permitted.

Max Dreisays:

Daniel, you have whetted (haha) my appetite to find out more about the case. On a TV quiz program last week I learned that coffee tastes better if you add to the weight of coffee beans in the grinder a few percent of liquid water before you press the button to start grinding. Who could have known? Who would have guessed?

On reading your comments I am thinking that IF the D9 powder is indeed useful for inhalation (that is, storage-stable) it can only be useful if it has been given a non-zero water content. Even if the manufacturer of the D9 powder had no idea of the importance of greater than zero water content, the water must have been there otherwise the powder they were making would not have been storage-stable. Under such circumstances, there would have been a novelty attack (even if one under Art 56 EPC would have failed).

But how to prove it. That’s the problem, in practice, for an opponent relying on D9. Perhaps the Board dismissed the opposition not because they thought that the claim was valid but because the Opponent (carrying the burden of proof) did not have enough evidence of its invalidity.

Perhaps the Opponent would have had better success with Art 115 observations prior to grant, a D9-based “poor man’s opposition” being more effective than that of a rich man?

Anyway, Daniel, Merry Christmas and all the best from me for 2024.

Avatar photoDaniel X. Thomassays:

Dear Max Drei,

Thanks for your further comments.

At a whisky tasting event, I learned that adding a few drops of water brings the aroma of whisky to bloom. I was sceptical, with my name no surprise, but it works!

The more I think of this case, the more I have doubts that the claimed product presents the required IS. N is given as there is one difference over D9.

It is common knowledge that powders have a tendency to clog when wet. Dry powder also can be explosive. Determining the water content which avoids clogging is the mere result of routine experiments. In view of the manufacturing process disclosed in the patent, reducing the water content after micronisation is necessary. The claimed water content appears to be the result of a mere bonus effect.

The application of G 2/21 in such a circumstance appears not to be correct. But you are right, it is also a question of argumentation.

On the other hand, tiotropium bromide powder is a golden nugget for the proprietor Böhringer Ingelheim (e.g. sold under the TM Spiriva Respimat). It has sued generic manufacturers.

From my side as well. Merry Christmas and all the best for 2024.

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