Practical Tips for Patenting Antibodies in Europe

The patenting of proteins is well established in Europe as long as they meet the requirements of novelty and inventive step.Antibodies are a specific type of protein, and to obtain useful patent protection for these, there are specific requirements to take into consideration.We have previously written about the European Patent Office's Guidelines for Examination in this area.Here we provide some practical tips for preparing a robust patent application to protect antibodies that may be of commercial interest.

As with patent applications for any invention, the description needs to include enough information to "teach" the skilled person how to make and use the invention.Essentially the patent specification has a specific format and content defined by law, which is intended to enable the reader to understand the invention sufficiently so that they can appreciate the nature of the invention and can put the invention into practice. For patent applications in the field of biotechnology, it is also important that the information in the description make it plausible that the invention works across the scope claimed, and at least some experimental data is usually required to demonstrate this. There are further special requirements for antibody patents.

A successful patent application will often tell a story relating to how and why the claimed subject matter is inventive.For an invention relating to antibodies, the following information is generally necessary to enable the drafting of an effective patent application:

1) A description of the nearest known technology (prior art), and an indication of the problems with that technology that are solved by the invention.

2) Full details of each of the antibodies to be protected, including structure and sequence information, preferably for both the target binding region and the constant region.This must include at least the six CDR sequences (unless there is experimental evidence that one or more of the CDRs does not interact with the target epitope).

3) A description of the elements expected to be commercially important (for example, specific fragments or combinations).

4) A description of how to make and use the antibodies/fragments, for example possible pharmaceutical formulations (this could refer to published standard methods if applicable).

5) Functional data to show that each antibody specifically binds to the target and has some functional effects as a consequence. Details of the test used, the conditions under which this was measured, and at least one full experimental example are required.This should ideally be described in general terms (optionally by reference to standard texts) and also include the specific experimental conditions that apply to the determinations of binding that were actually conducted: temperature, ionic strength, nature of target etc.

6) Direct experimental evidence showing that each antibody (and different combinations thereof if applicable) has an unexpected technical effect compared to pre-existing antibodies to the same target.This should be in the form of comparative data with known antibodies if possible.This could relate to improved affinity, improved therapeutic activity, reduced toxicity or immunogenicity or an unexpected species cross-reactivity. Affinity alone may not be sufficient to establish inventive step, so if this is important it may need to be combined with another characteristic.This should be accompanied by an explanation of why the technical effect was unpredictable.

7) An indication of what element of each antibody provides the unexpected technical effect should be provided.For example, whether it can be attributed to the CDR sequences alone, or whether the effect is also dependent on the framework regions. Experimental data demonstrating this should be included to support the claims.

8) For all experimental data, a description of what was done, how it was done (e.g. materials and methods), and a discussion of what the results demonstrate should be provided.

9) An indication of any further techniques/modifications.These should be real and reasonable. They should not include speculative additions which may not work or which cannot at this stage be described in sufficient detail to enable a skilled person to put them into practice.If the invention could be used in other applications or could be more versatile with certain changes or development, these should be mentioned.

10)An indication of all of the advantages of the antibodies to be protected and of preferred features.These should preferably be supported by experimental data.

It is perhaps a recognition of the increasing importance of antibody patents that the European Patent Office Guidelines for Examination now include an entire section (G-II-5.6) dedicated to antibodies and how they may be defined in a European patent application.