Wednesday, 21 December 2011

T 866/08 – Of Mice And Dogs

The patent proprietor filed an appeal against the decision of the Opposition Division (OD) to revoke the opposed patent on the ground of insufficiency of disclosure.

The OD argued that the therapeutic effect of the claimed vaccine had not been established. The prior art did not contain a disclosure of the use of a polynucleotide vaccine formula for treating dog diseases. In view of document D12, which had been published after the effective date of the patent, there were doubts as to whether the polynucleotide vaccines could replace the existing effective vaccines. Therefore, it was not possible to extrapolate the results obtained with mice .

Claim 1 of the main request before the Board read:
1. A vaccine inducing a protective response for canidae comprising a plasmid containing and expressing the G gene of the rabies virus and a suitable vehicle.
Here is what the Board had to say on sufficiency of disclosure:

*** Translation of the French original ***

[2] According to the established case law, when a claim covers a therapeutic application of a substance or a composition, it is not enough for the requirements of A 83 to be fulfilled that the skilled person can realize or obtain the compounds to be used based on the invention that is disclosed in the patent and/or on his common general knowledge; it is also necessary to establish that the claimed compound does indeed have a direct effect on a metabolic mechanism that is specifically linked to the disease to be treated. This mechanism may be known from the prior art or indicated in the application as such, e.g. via experimental trials. Once this has been proven, it is possible to take into account evidence that has been published at a later stage in order to support these conclusions (see T 609/02 [9]).

[3] In the present case, the patent does not provide any experimental data establishing that a plasmid expressing the G gene can induce a protective response against rabies in canidae.

[4] However, the OD has pointed out, in substance, that at the date under consideration there was no use of polynucleotide vaccines for treating dog diseases in the prior art for vaccinating dogs against rabies. Moreover, in view of document D12, which has been published after the effective date of the patent, there were doubts as to whether polynucleotide vaccines could replace the existing effective vaccines such as the vaccines against rabies. Based on these arguments, the OD was convinced that it was not possible to extrapolate in a systematic way the results of document D1, which had been obtained with a polynucleotide vaccine expressing the G gene in mice, to dogs, and that a vaccine tested on mice absolutely had to be tested on dogs in order to determine its effectiveness.

[5] The Board notes that the present patent under consideration covers a compound, the G protein of the rabies virus, which has been identified in the prior art as having the direct effect of producing an immune response in a great number of animals such as canidae (see e.g. documents D6 […], D13 […] and D18). In view of the common knowledge of the skilled person in the technical field under consideration, there was no doubt on the immunological effect of the claimed compound , i.e. its direct effect on the relevant metabolic mechanism, nor has the OD explicitly formulated such doubts.

[6] As a consequence, the impugned decision has to be understood as questioning the fact that polynucleotide vaccines carrying the G protein of the rabies virus can indeed induce the claimed effect (i.e. that the carrier used can produce the claimed effect in canidae) in view of the disclosure of document D12, which has been published at a later stage, rather than expressing doubts regarding the direct effect of the this gene on the immune system.

[7] First of all, the Board notes that document D12 has been published shortly after the priority date of the present patent and, therefore, was not part of the general knowledge of the skilled person. Moreover, table 1 of this document sums up 29 scientific articles that had been published during the three years preceding its publication and which deal with “DNA vaccines ... to induce some form of immunity against a dozen or more infectious agents” […], thereby establishing the functionality of those structures in a great number of animals. As the OD nevertheless indicated, document D12 expresses doubts as to whether polynucleotide vaccines could replace the existing effective vaccines. However, the Board notes that this does not shed doubt on the technical usefulness of those vaccines but only their superiority with regard to the existing effective vaccines. Therefore, the Board cannot endorse the opinion of the OD according to which document D12 can raise doubts that a polynucleotide vaccine such as the one claimed could lack functionality.

[8] The Board also notes that […] the impugned patent refers to document D1. It contains the statement that “as regards rabies, protection of mice against virulent challenge has been demonstrated after treatment with a polynucleotide vaccine expressing the gene for the G protein under the control of the SV40 virus early promoter [reference to D1], a similar result being achieved by using the CMV IE promoter.” The Board notes that document D1, therefore, also discloses that a vaccination with a plasmid carrying the gene for the G protein of the rabies virus induces a protective response against the rabies virus in mice.

[9] As a consequence, the Board considers that the disclosure of the prior art is such that the vaccine according to claim 1 is likely to be useful for the therapeutic application at which the claim is directed. Under these circumstances, the disclosure in documents D23, D29, D41 and D45 to D49, which have been published at a later stage, may be taken into account for supporting these conclusions. As a matter of fact, examples 20 and 21 of document D45, i.e. the U.S. patent that is equivalent to the impugned patent, contain experimental data which extensively disclose the short and long term protection of dogs that have been vaccinated with the plasmid disclosed in example 16 and administered according to the teaching of example 19 of the impugned patent.

[10] This is why the impugned patent is considered to disclose the invention in a manner sufficiently clear and complete for it to be carried out by a person skilled in the art, as required by A 83.

Should you wish to download the whole decision (in French), just click here.

The file wrapper can be found here.