12 February 2020
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Case 4 - T 801/06 (EPO Board of Appeal, 4 March 2009)

Now cited in the EPO’s “White Book” of case law, this decision offered illumination as to the level of disclosure required to claim a medical use.

With one of the strongest life sciences’ patent teams in Europe, we’ve always played an active role at the EPO – and in some of the most important legal decisions of the Boards of Appeal cited in the “White Book” or in the EPO Guidelines for Examination. In this series, we’re reviewing the ones we feel are most memorable in terms of making the law.

The patent in question here related to using a mutant herpes simplex virus (HSV) to treat cancer. The claims were directed to treating metastatic tumours in the central nervous system (for example occurring in the brain and spinal cord) and to treating melanoma. 

Metastatic tumours are cancerous tumours that start in one part of the body and then spread to another.  

The examples of the patent provided a variety of experimental data. This showed both infection of cultured melanoma cells with the HSV and infection of melanoma cells in a mouse brain using the HSV. The latter example used human melanoma cells that had been injected directly into a mouse’s brain, rather than mouse-derived cancer cells which had spread to the brain from a different area of the body. 

As a result, during opposition, the opponent argued that the examples did not provide data that reflected a “real” metastatic tumour – in other words, one that had spread to the brain of the same body.

An important outcome

The patent was maintained in amended form during opposition and Life Sciences Partner Richard Clegg (Mewburn Ellis, Manchester) handled the subsequent appeal for the patent proprietor. It was very important to the proprietor at the time to secure claims to the use of HSV in oncology. Happily, the Board of Appeal (BoA) overturned the decision during opposition, instead deciding to maintain the patent as granted. 

The fact that the experiments in the patent were not carried out with a ‘real’ metastatic tumour was not sufficient to deny sufficiency of disclosure.”

The BoA concluded that “a claimed therapeutic effect may be proven by any kind of data as long as they clearly and unambiguously reflect the therapeutic effect”. Therefore, the fact that the experiments in the patent were not carried out with a “real” metastatic tumour was not sufficient to deny sufficiency of disclosure. Also in the proprietor’s favour was the fact that the examples followed a “well-recognised system” for testing HSV. 

The BoA’s conclusion is cited in the compendium of EPO case law with respect to sufficiency of disclosure. The decision provided clarity on the level of disclosure required to claim a medical use.

It also paved the way for applicants to rely on in vitro data and model systems to support claims describing a therapeutic effect. Such data tend to be easier to provide compared to those obtained by in vivo studies.

Find the decision here.

This blog was drafted by Anna Mudge.

Richard is our Managing Partner and is responsible for leading the Management Board to devise and deliver the firm's strategy.  He has extensive experience in the biotechnology and pharmaceutical sectors. He works closely with clients to establish a compelling commercial IP position. Richard and his team help clients to generate active and valuable patent portfolios, defending key patents on a global basis, conducting freedom to operate analyses and taking effective action against competitors.

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