Anonymous medical client

Taking a scalpel to a European patent

We work with a well-known multinational medical devices company. Our client became aware of a competitor’s European Patent which had been granted by the European Patent Office (EPO) with very broad claims after limited examination.

Case Study

Case Type

Mitigating FTO risks


Patent opposition


Patent entirely revoked

Dr Andrew Alton

By Dr Andrew Alton



The breadth of the granted patent caused potential Freedom to Operate (FTO) risks for our client in an area of commercial interest. A cost-effective way of mitigating that risk was needed.


Rather than spend our client’s time and money on unnecessary work, we dissected the competitor’s patent to find a rare attack to reduce our client’s commercial risks.

We prepared an opposition to the patent based on prior art supplied by our client, and our detailed legal analysis of the patent. Further research identified other sources of potentially relevant prior art, which would otherwise have been hard to find.

A careful review of how the patent application had progressed, from first filing in the US through examination at the EPO, enabled us to identify a potentially fatal flaw in the patent, one which was not spotted by the original EPO Examiner. We prepared detailed legal arguments explaining why the invention described in the patent was not the same as the invention actually claimed by the patent, an argument which only succeeds in 1% of cases.

We also identified an unorthodox added matter attack — that the invention as presented in the application as filed, and the invention as presented in the granted patent, were different.


The strength of the arguments in the initial opposition meant that no further arguments needed filing during the opposition procedure, despite further submissions by the patent owner. This kept costs proportionate to the perceived relevance of the patent to our client at the time.

Unusually, the Opposition Division started the Oral Proceedings with our ‘insufficiency of description’ attack on the patent. The patent owner could not overcome the objections, and all five of the patent owner’s requests to try and amend and fix the patent were refused. We managed to revoke the patent entirely for not accurately describing the invention it actually protected.

Relatively few EPO oppositions (about one in four in 2017) result in the patent being entirely revoked. In addition, very few patents for mechanical inventions, such as this, are finally revoked for insufficiency (less than 5% in 2014).

The EPO’s decision to revoke the patent has, however, been appealed and we have been instructed to handle the appeal at the EPO.

For more information please contact Andrew Alton

0113 245 2388

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