Assessment of unity of invention

Avoid literal or over-technical approaches

6.36 In addition to the actual tests applied in the unity consideration, there is significant variation in the “strictness” of approach applied by Examiners. The PCT Guidelines provide some general examples of where unity may or may not arise, but in practice the unity determination is largely a matter of individual judgment based on the facts of the case. In this regard, the Guidelines set out that:

Although lack of unity of invention should certainly be raised in clear cases, it should neither be raised nor persisted on the basis of a narrow, literal or academic approach. There should be a broad, practical consideration of the degree of interdependence of the alternatives presented, in relation to the state of the art as revealed by the international search or, in accordance with Article 33(6), by any additional document considered to be relevant. If the common matter of the independent claims is well known and the remaining subject matter of each claim differs from that of the others without there being any unifying novel inventive concept common to all, then clearly there is lack of unity of invention. If, on the other hand, there is a single general inventive concept that appears novel and involves inventive step, then objection of lack of unity does not arise. For determining the action to be taken by the Examiner between these two extremes, rigid rules cannot be given and each case is considered on its merits, the benefit of any doubt being given to the applicant.

6.37 Lack of unity a posteriori is particularly open to a “narrow, literal or academic approach” since in theory any novelty or inventive step objection could potentially result in a further objection on lack of unity for any further variations not covered by the novelty/inventive step objection. In such cases each and every further variation could be considered a further invention (in the chemistry area this could amount to thousands of additional inventions). This is clearly not the intention of the unity requirement. If an a priori consideration of the claims has determined that the claims have unity, then careful consideration needs to be made as to whether the prior art significantly impacts on that decision.

6.38 Notably, the PCT Guidelines set out two extremes – situations where the common feature is well known and unity clearly is lacking and those where there is clearly a novel and inventive feature in common and unity is evident. Between these the situation is less clear, but it could be considered that unity might be raised if a feature is not well known, but rather is disclosed in a document that might not ordinarily constitute common general knowledge (essentially the feature is public knowledge rather than common general knowledge). Situations where unity would be unlikely to be raised, except in exceptional circumstances, would be where a document provides only a generic disclosure of the feature, or where the features are obvious in view of a combination of documents.

6.39 As noted in the PCT Guidelines the applicant should be given the benefit of doubt. An objection of lack of unity can potentially lead to the applicant filing divisional applications for additional inventions. This can be costly for the applicant, who will need to pay significant additional costs to prosecute these divisional applications.

6.40 Furthermore as set out in the PCT Guidelines, there should be a broad, practical consideration of the degree of interdependence of the alternative inventions. Depending on the specific circumstances of the case, a lack of unity may be “technical”, and the key issue may instead lie in whether the claims are inventive, fully supported or clear in scope. Thus, a practical approach might be to consider inventive step, full support or clarity rather than unity. For example, if an initial consideration of the dependent claims does not identify any feature that would confer inventive step then a “broad brush” approach can be taken under inventive step rather than taking a “technical” objection of lack of unity. Another example would be if the claims have an unduly broad scope and are only partially supported by the disclosure, the Examiner adopting a practical approach may limit the search to the supported subject matter instead of raising a unity objection. More examples are provided below to further illustrate the consideration for lack of unity.

6.41 In some cases the common technical feature may not be readily apparent and can result from different properties of the invention. For example:

1. A polypeptide having activity X comprising SEQ ID No: 1 wherein the sequence possesses mutations at one or more of the positions 4, 19, 143 and 244

In this case the different point mutations are at quite different and remote positions of the peptide. Prima facie, these are different inventions. However, the activity of the peptide may relate to the binding at a particular receptor site. Proteins may adopt a tertiary structure where an active site comprises quite distant amino acids. In this case the mutations may be related to a single binding site where mutations of the amino acids result in changes to the same binding site, which has a technical effect not previously disclosed in the art. This could therefore be the special technical feature the different proteins have in common.

6.42 Similarly, if the invention relates to a new property of a related group of articles (some of which are known and some of which are new), then the group will comprise a single inventive concept based on the new property. An a posteriori lack of unity does not arise as a result of some of the articles being known. Such situations are likely to arise in the chemical area. For example, if a group of related chemical compounds comprising a number of known compounds as well as a number of unknown compounds is useful in treating a certain disease, then claims to the new use, compositions for the particular use, claims to any novel compounds and methods for the preparation of the novel compounds would constitute a single invention.