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Case law 8 Nov 2021

Unallowable intermediate generalisation

For this examination Appeal the applicant amended a claim towards an embodiment that was only disclosed in the examples. In doing so, the Applicant generalized features that were present in these examples. The invention concerned a controlled release system for a specific drug, risperidone. The Board assessed whether the combination of features as claimed would have affected the outcome of the examples (the drug release profile). Considering that the application itself described these features as relevant for the drug release, this was deemed to be the case and the Board judged that an unallowable intermediate generalization was at stake.
The question was whether these features ‘determine the properties of this embodiment as a whole to a significant degree'

The invention is directed to a sustained delivery system for risperidone which is an antipsychotic medication. The sustained delivery system concerns an injectable polymer matrix that forms upon injection a subcutaneous gel implant which releases the risperidone over a time period of 1-3 months. The polymer concerned is poly(DL-lactide-co-glycolide), abbreviated as PLGH.

The appeal concerns a divisional application that was refused by the Examining Division. This divisional was filed with a claim directed towards a flowable composition comprising, amongst others, PLGH with a weight ratio of lactide to glycolide from 75-85 to 25-15. Although the end-values of this range (i.e. 75/25 and 85/15) were in the application as filed, the range was not and the ED considered this range therefore to violate article 123(2). As a response, the Applicant limited to a weight ratio of 80/20 and referred to example 4 for basis.

After several further amendments made during examination the ED finally refused the application on the basis of an unallowable intermediate generalization of the embodiment disclosed in example 4 and therewith violating article 76(1) and 123(2). The refused claim 1 was as follows:

A flowable injectable composition comprising:
15 weight % risperidone in;

  • (i) 45 weight % of a biodegradable thermoplastic polymer that is at least substantially insoluble in body fluid, wherein the polymer is a 80/20 poly (Dl lactide-co-glycolide) with a terminal carboxy group;
  • (ii) 55 weight % of N-methyl-2-pyrrolidone;

wherein the biodegradable thermoplastic polymer has a molecular weight of 10,000 Daltons to 45,000 Daltons, optionally 15,000 Daltons to 40,000 Daltons;
wherein the composition has a volume from 0.3 ml to 1.0 ml."

The applicant appealed the refusal decision; in Appeal this issue was discussed by the Board as follows.

Firstly in reason 1.3 the well-developed case law for intermediate generalization was discussed and T 714/00 was referred to: ‘extracting an isolated feature from an originally disclosed combination and using it for delimiting claimed subject-matter can only be allowable under the concept of Article 123(2) EPC if that feature is not inextricably linked with further features of that combination and thus not so closely associated with the other features of the combination as to determine the properties of this embodiment as a whole to a significant degree.

Example 4 concerned purified PLGH (PLGHp) and a molecular weight of 42,000 Daltons. Example 5 which concerns the same composition as example 4 disclosed volumes of 0.4, 0.6 or 0.6 ml. The examples concerned the effects on risperidone release. Claim 1 was broader than the example considering the claim does not mention purification, has a wider range of molecular weight and a wider range of volumes. Question was if the broader features in the claim are allowable. In more detail and following T 714/00 question was whether these features ‘determine the properties of this embodiment as a whole to a significant degree’.

For answering this question the Board brings forward under reason 1.5 that the application itself explains that purification has an influence on the ‘burst qualities’ and that molecular weight inversely affects the rate of risperidone release. ‘Burst quality’ also relates to risperidone release. The Board therefore found that these properties determine the embodiment as a whole, so the claim concerned an unallowable intermediate generalization.

In addition, also the generalization of the volume range was deemed unallowable since  specific dosing was tested together with specific concentrations of risperidone in the context of a pharmacokinetic and pharmacodynamics study in dogs. These specific volumes are therefore closely associated and cannot be generalized.

Auxiliary request 1-4 that were on file were deemed unallowable for similar reasons as the main request. The applicant also filed auxiliary request 5 during the oral proceedings. Even though this amendment remedied the Article 76(1) and 123(2) problems on file, the Board did not allow this request. The Board saw no exceptional circumstances according Article 13(2) RPBA (2020). The conclusion of the Board on the main request and AR’s 1-4 was not different from the preliminary opinion, so the applicant should have acted earlier. Moreover the Board was still not fully convinced on Article 76(1) and 123(2) considering the tests in example 4 and 5 were on dogs; the Board had doubt if the result could be translated to humans.

In the end the Appeal was dismissed.

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