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Case Law of the Boards of Appeal

 
 
6.3. Level of disclosure required for antibodies

In T 431/96 the skilled person seeking to reproduce the invention would have had to produce monoclonal antibodies by routine methods and test them singly in an assay. Although this might possibly involve some tedious and time-consuming work, it was nothing out of the ordinary since the techniques for the production and selection of hybridomas were common routine techniques at the priority date of the patent in suit.

The board found that the essential issue to be considered in T 601/05 of 2.12.2009 was whether or not the patent enabled the production of human monoclonal antibodies binding with high affinity to soluble TNF and, consequently, whether or not the skilled person could practise the invention over the whole scope of the claim (following T 792/00). On the evidence before the board it did not.

In T 1466/05 the question arose whether the availability of a hybridoma producing one specific antibody together with a general description of the epitope recognised by this antibody put the skilled person in the position to obtain further antibodies with the same specificity. The board observed that similar questions had arisen in various cases decided by the boards of appeal, and different boards had given different answers depending on the circumstances of each case (T 510/94, T 513/94, T 349/91, T 716/01).

In T 1466/05 the claim was not restricted to monoclonal antibodies defined by reference to the deposited hybridoma. As the application did not disclose any specific antigen for preparing further antibodies as claimed, the board considered that a skilled person seeking to prepare such antibodies would have had to embark on a research programme without any teaching in the application as how to achieve the desired specificity which amounted to an undue burden.

The claim at issue in T 405/06 was directed to immunoglobulins with certain stated features. The question to be answered was whether a skilled person would have found at the filing date in the application as filed a sufficiently clear and complete disclosure of the precise structure of such an immunoglobulin in order to be in a position to prepare it over the broad range of the claim. Although the claim was not limited to immunoglobulins obtained from camelids, the experimental part of the description as a whole and the corresponding figures dealt exclusively with camel immunoglobulins and the general part of the description did not contain a complete disclosure of any non-camelid immunoglobulin either. The requirements of Art. 83 EPC 1973 were thus not satisfied, as the skilled person would be left with the task and burden of finding out how the teaching relating to camelid immunoglobulins could be extended to products of different origins (e.g. human immunoglobulins) falling within the broad area of the claim.

The application the subject of T 433/07 concerned broadly reactive opsonic antibodies that react with common staphylococcal antigens. The board held that the invention was insufficiently disclosed; the application did not disclose either any serotype cross reactive monoclonal antibody or the isolation of an antigen associated with the serotype cross protective response required by the claim. A European patent application containing a claim referring to a method of production had to provide the skilled person with the means to produce the desired product. If this was not the case, this shortcoming could not be overcome by telling him exactly how the desired product had to look and which screening criteria had to be applied to find it.

In T 617/07 the claim at issue concerned monoclonal antibodies and synthetic and biotechnological derivatives thereof defined by structural and functional features. The board found that, given his common general knowledge, the skilled person would be able, in a possibly time-consuming but straightforward manner, to provide antibody variants having the functional requirements indicated in the claim. There was no doubt that the structural definition in the claim included antibodies that did not have the desired function but, when attempting to rework the invention the skilled person would on the basis of his knowledge be able to avoid non-functional variants. Therefore, because the skilled person knew how to achieve antibodies with the desired function on the basis of a particular known antibody, he was not in the situation of having to sort out non-functional variants in a burdensome manner.

In T 386/08 the patent concerned humanized antibodies with framework sequences. It disclosed not only one, but many examples. The board pointed out that the concept of sufficiency of disclosure over the whole scope of the claim did not mean that, for a disclosure to be considered as sufficient, it had to be demonstrated that each and every conceivable embodiment of a claim could be obtained; see G 1/03 (OJ 2004, 413). There may be situations where the specification contains sufficient information on the relevant criteria for finding appropriate alternatives ("variants") over the claimed range with reasonable effort. Under these circumstances the non-availability of certain variants encompassed by the claim at the priority date is considered immaterial for the sufficiency of disclosure. For an example where this was not so, see T 601/05. The current situation however was different in that the patent described quite a number of appropriate alternatives and in that the allegedly non-obtainable variants were "hypothetical" variants. The requirements of Art. 83 EPC were fulfilled.