Now that the Boards of appeal are not competent for the review of invitations to pay additional search fees under the PCT (Rule 40.2 PCT; old-timers will remember the “W” decisions) any more, unity of invention has become a relatively rare issue in Board decisions.
In the present case the application under consideration had been refused for lack of inventive step and unity of invention.
The independent claims on file before the Board read:
1. A method of optical imaging of oesophageal cancer and Barrett’s oesophagus of an animate subject involving administering an optical imaging contrast agent to the subject and generating an optical image of at least a part of said subject to which said contrast agent has distributed; wherein said contrast agent has a molecular weight below 14,000 Daltons and an affinity for an abnormally expressed biological target associated with oesophageal cancer or Barrett’s oesophagus, said biological target being selected from: E-cadherin, CD44, P62/c-myc (HGF receptor), p53 and EGFR/erB-2.7. Use of the contrast agent as defined in any one of claims 1 to 4 in the manufacture of a diagnostic agent for use in a method of diagnosis of oesophageal cancer and Barrett’s oesophagus involving administration of said diagnostic agent to an animate subject and generation of an image of at least part of said subject.8. The contrast agent as defined in any one of claims 1 to 4 for use in a method of diagnosis of oesophageal cancer and Barrett’s oesophagus.
The Board examined whether there was unity of invention:
[2.1] When deciding on unity of invention, it is mandatory under A 82 to determine whether or not the inventions or groups of inventions as claimed form a single general inventive concept. According to R 44, the requirement of unity of invention under A 82 shall be fulfilled only when there is a technical relationship among those inventions involving one or more of the same or corresponding special technical features, i.e. features which define a contribution which each of the claimed inventions considered as a whole makes over the prior art.
According to the established jurisprudence of the boards of appeal (see e.g. W 11/89 [4.1]), the assessment of unity of invention requires as a precondition an analysis of the technical problem or problems underlying the respective group(s) of invention(s) based on the disclosure of the application as originally filed. As a next step, it has to be determined whether or not the solution to this problem makes a contribution over the prior art.
[2.2] In the present case, the problem underlying the present invention may be defined as the provision of contrast agents for optical imaging of oesophageal cancer or Barrett’s oesophagus in patients […]. This problem was solved by the subject-matter according to present claim 8 comprising five groups of contrast agents, characterised by their affinity to either E-cadherin, CD44, P62/c-myc, p53 or EGFR/erB-2. These five groups of contrasts are a priori linked by (a) a molecular weight of < 14,000 Daltons and (b) by the common effect of having affinity for an abnormally expressed biological target associated with oesophageal cancer or Barrett’s oesophagus. It is therefore possible to formulate a common concept, which can be defined as follows: provision of a contrast agent for optically imaging of oesophageal cancer or Barrett’s oesophagus, wherein said contrast agent has a molecular weight below 14,000 Daltons and an affinity for an abnormally expressed biological target associated with oesophageal cancer or Barrett’s oesophagus. In the absence of any prior art, the thus defined common concept also constitutes a priori a single general inventive concept as required by a 82.
[2.3] The objection of the examining division was, however, directed to lack of unity a posteriori, taking into account the teaching of document D2.
Document D2 discloses optical imaging agents comprising a fluorescent dye conjugated to a short-chain peptide having affinity to somatostatin receptors, VIP receptors or neurotensin receptors, all of which are abnormally expressed in tumoral cells. Said compounds are particularly suitable for the diagnosis or hollow organs including the oesophagus […]. Compared to antibodies the short-chain peptides carrying the fluorescent dye are characterised by advantageous properties such as reduced blood half-live and less allergenic side effects […].
It follows therefrom that the common concept defined in paragraph [2.2] above is not novel in the light of document D2. In this context, it is noted that document D2 does not explicitly mention contrast agents with a molecular mass of below 14,000 Daltons. However, a molecular mass of below 14,000 Daltons is implicitly disclosed therein, as the fluorescent dye is covalently bonded to short-chain peptides […], so that the molecular mass of the resulting product is automatically below 14,000 Daltons. In view of the fact that the above-mentioned common concept is not novel and that it is not possible to formulate an alternative common concept for the invention claimed in claim 8, there is lack of unity of invention.
Alternatively, making reference to R 44, it can be reasoned that in the light of the teaching of document D2, claim 8 does not contain any special technical features, either of the same or the corresponding type, which could make a contribution over the prior art.
The requirements of A 82 are therefore not met.
[2.4] The above reasoning applies mutatis mutandis to the further independent claims, which concern a method claim (claim 1) and a Swiss-type claim (claim 7) involving the same contrast agents.
Further arguments of the appellant
[2.5] Regarding the argument that there was no teaching in document D2 that the somatostatin receptors, VIP receptors or neurotensin receptors were involved in oesophageal cancer, reference is again made to page 3, lines 1-28, according to which these receptors are overexpressed in tumour cells and tumour tissue which can be used for diagnosing hollow organs such as the oesophagus. This means that diagnosis of tumours which are located in the oesophagus constitutes a preferred embodiment of the more general teaching, according to which the receptors mentioned above are used for diagnosing tumours in hollow organs. The fact that document D2 does not contain a specific example describing the diagnosis of the oesophagus is of no consequence, as the description […] contains numerous fluorescent dyes and short-chain peptides which […] are suitable for diagnosing hollow organs including the oesophagus. As a consequence, this argument cannot succeed.
[2.6] In view of this finding, the evaluation of inventive step is not necessary.
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