EPO: Proving plausibility before the EPO

Managing IP is part of Legal Benchmarking Limited, 1-2 Paris Gardens, London, SE1 8ND

Copyright © Legal Benchmarking Limited and its affiliated companies 2025

Accessibility | Terms of Use | Privacy Policy | Modern Slavery Statement

EPO: Proving plausibility before the EPO

A common dilemma for inventors and applicants before the European Patent Office is whether an invention is sufficiently mature for a patent application to be filed. Although a proof-of-concept is often established at the date of filing, an inventor does not always have the opportunity to investigate every aspect of their invention before a patent is filed.

Typically, the EPO has been more relaxed than the USPTO or SIPO regarding this issue, and if an applicant at the EPO encounters an objection that a particular aspect of a claimed invention is not sufficiently disclosed, such an objection can typically be overcome by providing experimental evidence to the EPO that the aspect in question actually works as proposed. Experimental evidence of this nature can be post-published, i.e. the patent application can be supported by experiments carried out after the filing date.

EPO case law requires in principle that a patent claim should be examined for compliance with the requirements of sufficient disclosure (Article 83 EPC) on the basis of the application documents as originally filed. In practice, however, this requirement has not been strictly applied, and patents and patent applications often survive objections of lack of sufficiency, especially if post-published data can be provided.

Some recent decisions of the EPO Boards of Appeal in the pharmaceutical field have developed the existing case law around how plausible the technical effect of an invention must be at the filing date of the patent application.

In decisions T 0488/16 (Dasatinib I) and T 0950/13 (Dasatinib II), the Board required that the technical problem underlying the invention was at least plausibly solved at the filing date. This required technical evidence if the effect is "neither self-evident nor predictable or based on a conclusive theoretical concept". Post-filed evidence and declarations by experts that the products did in fact work as envisaged were not sufficient, and the patents were deemed to lack inventive step.

Decision T 2500/12 (Alzheimer) concerned an immunogen for a pharmaceutical composition in the accepted second-medical use form (for use in the treatment, prevention or amelioration in an animal of Alzheimer's disease or other diseases characterised by amyloid deposits). The Board was not convinced that the suitability of the immunogen claimed for the particular treatment was shown in the application as filed, or in the prior art. The patent claim was found to be insufficiently disclosed.

If these decisions form part of a trend, obtaining valid patent claims on the more speculative aspects of an invention may prove to be more difficult before the EPO.

Edward J Farrington

Inspicos A/S

Kogle Allé 2

DK-2970 Hoersholm

Copenhagen, Denmark

Tel: +45 7070 2422

Fax: +45 7070 2423

info@inspicos.com

www.inspicos.com

more from across site and SHARED ros bottom lb

More from across our site

National groups for the UK and the Netherlands have flagged concerns with the choice of venue, following a formal complaint from Australia’s national group
Rasenberger is the CEO at the Authors Guild in the US
Vold-Burgess is the client director at Acapo Onsagers and the former CEO at Acapo in Norway
Williams is the CEO of the UKIPO in the UK
Orliuk is director of the Ukrainian IP office
Julie is chief IP counsel at Teva in the US
Ludlam is chief IP and litigation officer at Lenovo, while Maharaj is chief licensing officer for Ericsson in the US
Campinos is the president of the EPO in Munich
AlSwailem is the CEO of Saudi Authority for Intellectual Property in Saudi Arabia
Ridings, Orozco and Diego-Fernández Andrade are appeal arbitrators at the WTO in Switzerland
Gift this article