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Sufficiency and lack of data

Article 83 of the European Patent Convention (EPC) states thatThe European patent application shall disclose the invention in a manner sufficiently clear and complete for it to be carried out by a person skilled in the art.”  This means that the description must describe the invention in a manner which makes the claimed invention credible. This may be by providing details of at least one way in which the invention may be successfully carried out, or by providing sufficient data to demonstrate that a claimed effect is observed across the scope of the claims. The person skilled in the art should be able to use the specification to put the invention into practice without undue burden, and without needing to exercise inventive skill.

When assessing a patent application to determine whether this standard has been met, consideration should be given both to the teaching provided in the specification and to the common general knowledge at the filing date. Where an examiner considers that this has not been met, the application may be objected to for lack of sufficiency.

It is important to be aware of the need for an application to be sufficient at the point of drafting, as lack of sufficiency cannot be remedied by the later submission of data: the application must be sufficient at the point of filing. It is therefore important to ensure that sufficient data and examples are included in any patent application to make the claimed invention credible.

If you get an objection of lack of sufficiency then, provided that the application contains some data and is not purely speculative, it may be possible to address the objection by limiting the claims to match the subject-matter for which data has been provided more closely. For example, where a claim covers a large number of compounds defined by a broad Markush formula, but data is only provided to show that a small number of compounds with a limited set of substituents are effective, then limitation to that small set of compounds may overcome the sufficiency objection.

The EPO does not require that evidence be provided to demonstrate that every permutation of the claimed invention is effective, and a reasonable extrapolation from the data should be permitted. However, options for amendment may be limited by the EPO’s strict approach to added subject matter. If intermediate fall-back positions are not clearly outlined in the specification, then amendment to such a position may not be possible, and it may be necessary to limit the claims to the specific examples for which data has been provided in order to meet both the requirement for sufficiency and the prohibition on adding subject matter.

The best time to ensure sufficiency is during the drafting process. Some tips for drafting to maximise the chance your application will be found to be sufficient are:

  • Ensure examples and/or data are provided to show that the claimed invention is credible.
  • Make sure at least one successful method of carrying out the invention is described.
  • For chemical cases in which a compound is defined by a broad Markush formula, provide a number of examples showing efficacy over a range of the claimed compounds with varying substituents.
  • Where the claims include parameters, ensure that the application describes the methods to be used in taking measurements (particularly where there are multiple options and/or where these are not common general knowledge).
  • Provide intermediate fall-back positions between the broadest statement of invention and the specific examples for which data is provided.

If you have any queries about this, please contact us and we would be happy to advise you.

You can also read previous article regarding sufficiency: Transferring the burden of proof in sufficiency to the patentee

Author: Katherine Wright

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