T 2321/15 - Problem invention accepted

Key points

• The Board accepts inventive step based on a problem invention.
•  "Consequently, the Board considers that the problem posed by the contested patent [the presence of air pockets in the freeze dried porous microspheres, and the resulting difficulties in rehydrating the particles] is an unrecognized problem in D4 [the closest prior art]."  
• " The discovery of a yet unrecognised problem may give rise to patentable subject-matter in spite of the fact that the claimed solution is retrospectively trivial and in itself obvious ("problem inventions"). The question regarding the inventive step, in relation to the modification of the process of D4, is not whether the skilled man could have added a sealing and storage step under vacuum, but whether he would have done so in expectation of some improvement or advantage. " 
• " Since the process disclosed in D4 appears to be satisfactory, the addition of a further process step would have appeared superfluous, wasteful and devoid of any technical effect. In view of the recognition that a sealing and storage step under vacuum has a substantial proven effect, the outcome was not predictable and the claimed modification involves an inventive step on this basis. "

EPO T 2321/15 - link

3. Main request - Article 56 EPC

3.1 The invention relates to methods for formulating easily rehydratable dried pharmaceutical compositions made from swelling particles, which are used as chemo-embolic compositions. One problem with freeze drying gels, such as porous microspheres is that air pockets develop within the microspheres as the water is removed during the drying process, which is problematic when the dry beads are rehydrated.

3.2 The closest prior art is D4, which discloses the preparation of PVA porous microspheres comprising an active agent for embolization, by a method involving a freeze-drying step (see pages 8-9 and examples 23-26). This document does not disclose a sealing step under vacuum, but mentions that "the vials can be sealed, in situ, under a protective atmosphere if required" (see page 10, lines 8-9). Examples 25 and 26 of D4 mentions the rehydration of microspheres.

[...]3.4 As a solution to this problem, claim 1 of the main request proposes a packaging step carried out under reduced pressure and that the package containing the particles is substantially airtight and has an interior under vacuum. [...]

Consequently, there is sufficient evidence supporting the alleged effect, namely that said step(s) performed under vacuum suppresses the unwanted air pockets, and improves the rehydration properties and also the dispersion properties of the particles.

3.6 The question remaining is whether the skilled person, starting from the disclosure of D4 would arrive at the subject-matter of claim 1 of the main request in an obvious manner in order to solve the problem posed.

3.6.2 In the present case, D4 does however not mention the presence of air pockets in the porous microspheres and any of the problems linked thereto. Examples 25 and 26 of D4 show the rehydration of the microspheres composition and do not mention any problem linked with said rehydration.

D4 suggests on page 10 of the description the use of a protective atmosphere during the lyophilisation step and the sealing, which demonstrate rather a concern about stability and protection against degradation due to atmosphere. Hence, said passage on page 10 also suggests that the problem linked with the presence of air pockets in the porous microsphere was not identified in D4, since the use of a protective atmosphere during the sealing step would not allow to suppress the air pockets.

Consequently, the Board considers that the problem posed by the contested patent is an unrecognized problem in D4. The discovery of a yet unrecognised problem may give rise to patentable subject-matter in spite of the fact that the claimed solution is retrospectively trivial and in itself obvious ("problem inventions"). The question regarding the inventive step, in relation to the modification of the process of D4, is not whether the skilled man could have added a sealing and storage step under vacuum, but whether he would have done so in expectation of some improvement or advantage. Since the process disclosed in D4 appears to be satisfactory, the addition of a further process step would have appeared superfluous, wasteful and devoid of any technical effect. In view of the recognition that a sealing and storage step under vacuum has a substantial proven effect, the outcome was not predictable and the claimed modification involves an inventive step on this basis. There is therefore no indication, incentive or suggestion, when starting from D4, to make a sealing and storage under vacuum.

The Board can therefore not follow the decision of the opposition division, which made an ex post facto analysis of the situation.

[...]

3.7 The solution according to the subject-matter of claim 1 is therefore not obvious and it follows that the process of claim 1 involves an inventive step.

The main request meets the requirements of Article 56 EPC.

Order

For these reasons it is decided that:

1. The decision under appeal is set aside.

2. The case is remitted to the opposition division with the order to maintain the patent on the basis of the main request and a description to be adapted.