29 January 2020
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Case 3 - T 1642/06 (EPO Board of Appeal, 23 August 2007)     

The Technical Board of Appeal was persuaded that the application described a different approach to targeting tumours.

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 application concerned sigma receptor ligands, which have been shown to induce apoptosis (cell death) preferentially in tumour cells, while sparing non-diseased cells.

The application included claims concerning the use of sigma ligands in methods of treatment, leading to altered survival of normal endothelial cells (which form the lining of blood vessels).

The examining division argued that these claims lacked novelty, because a prior art document disclosed the treatment of breast cancer using a sigma ligand. The examining division determined this was the same clinical situation covered by the claims.

Indirect effect

Representing the applicant in the appeal, Life Sciences Partner Simon Kiddle argued that although a sigma ligand may be known to treat breast cancer, the invention in the application lay in the identification of a new technical effect – namely altering the proliferation or survival of endothelial cells.

“The invention in the application lay in the identification of a new technical effect”

The prior art document disclosed use of sigma ligands to induce tumour cell division cycle arrest or apoptosis. In other words, it described a direct effect on cancer cells.

In contrast, the new technical effect in the application related to the indirect influence of sigma receptor ligands on cancer cells via the inhibition of the neovascularisation (new blood vessel formation) of tumours.

New clinical situation

This new technical effect therefore identified a new clinical situation, in which it could be preferable to target the supporting vasculature of a tumour instead of the cancer cells themselves. For example, the new effect could be useful in cases where cells are resistant to chemotherapeutic drugs.

It was concluded, then, that the claims were novel in view of the cited prior art document.

This decision supports the principle that if a new clinical situation can be identified, treating patients suffering from the situation with a compound can form the basis of a novel claim – even if that compound is known. 

Find the decision here.

This blog was written by Daniel Yin.

Simon is a Partner and Patent Attorney at Mewburn Ellis. He also heads up the firm’s Life Sciences practice group and is a member of our management board. Simon has more than 30 years’ experience in original patent drafting, patent strategy European oppositions and appeals, including complex multi-party proceedings, and due diligence work, across the life sciences field for both large and small molecule therapeutics. He has worked on the portfolios covering many top selling biologics and has been at the forefront of patenting in the field of precision medicine and life cycle management for therapeutics.

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